HK1022108A - Intraluminal radiation treatment system - Google Patents

Description

Intraluminal radiation therapy system

The present invention relates generally to an intraluminal radiation treatment system for delivering a treatment unit to a selected site in an intraluminal passage of a patient via a catheter. More particularly, the present invention relates to an improved delivery device for operating and delivering a treatment unit to a catheter and an improved catheter assembly.

Background

Balloon angioplasty has been widely used since the seventies to open coronary artery occlusions. Briefly, this technique allows for the dilation of an artery by advancing a balloon catheter to the site of the arterial stenosis and then inflating the balloon to dilate the artery and thereby open the artery for a greater volume of blood to pass through. Atherectomy techniques (atherectomy techniques) in which the artery is occluded or removed, or reduced in size, may also be used for the same purpose.

Although balloon angioplasty has proven to be an effective method of opening an artery, in extreme cases, the artery may become re-constricted at the site of initial balloon dilation, a constriction referred to as restenosis. Restenosis is believed to be caused by the formation of scar tissue at the site of angioplasty, which is the result of injury to the artery due to balloon dilation.

Recently, intraluminal radiation therapy has been applied to treat diseased sites in arteries following angioplasty or atherectomy to prevent cell proliferation and wound healing responses, thus helping to prevent restenosis from occurring. Methods and apparatus for such intraluminal radiation therapy are disclosed in related, co-pending patent applications having patent application numbers and filing dates, respectively, of 4.4. 08/628,231,1996, the contents of which are incorporated herein by reference. The above-mentioned patent application generally discloses a device comprising a catheter which is inserted into a lumen of a patient and advanced to the site of the area to be treated; and a delivery device that assists in advancing or withdrawing each radiation treatment unit or "seed" to or from the treatment site, either hydraulically or pneumatically, along with the catheter.

As with any device inserted into the vascular system, the device must have substantial integrity to ensure that no components or units are separated or dislodged from the device and into the vascular system. This is particularly true for treatment units that are moved towards or away from the distal end of the catheter. In addition, because the device employs a radiation therapy unit, safety is further needed to prevent the patient or operator from being exposed to radiation that should not be obtained.

The device disclosed in the above-identified, co-pending patent application finds several areas in its use that can be improved to reduce the likelihood of the treatment unit falling out of the system, thereby increasing patient and operator safety.

It is therefore a primary object of the present invention to provide a delivery device and catheter assembly having increased safety for protecting the patient and operator.

More particularly, it is an object of the present invention to provide a delivery device/catheter assembly in which the catheter is not inadvertently detached from the delivery device unless all of the treatment units are present in the delivery device. It can also be said that it is an object of the present invention to provide a delivery device/catheter assembly in which no treatment unit can exit the delivery device unless a catheter is attached to the delivery device.

It is another object of the present invention to ensure that the hydraulic or pneumatic pressure experienced by the delivery device/catheter assembly does not exceed a predetermined "safe" pressure during advancement and retrieval of the treatment unit.

It is a further object of the present invention to provide a method and system that can detect the presence or absence of a treatment unit in a delivery device and can display the results of the presence or absence of a treatment unit.

Summary of The Invention

These objects, as well as others which will become apparent upon reference to the detailed description set forth below, are accomplished in one aspect by an actuation assembly for operating a delivery device, the actuation assembly including a valve member movable between a first position preventing access to a catheter lumen and a second position permitting access to the catheter lumen. The valve is movable to the second position only when the conduit is connected to the delivery device. The actuating assembly includes a switch member which is biased to a first position in which it prevents movement of the valve member to its second position unless the switch member is moved from the first position in which it interferes with movement of the valve member when the conduit connection is received by the central aperture of the transfer device. In addition, a trigger element is provided which, when the catheter connector is arranged in the central bore, is brought into a state in which it locks the connector and can be released by means of a separate release button.

In another aspect of the invention, a pressure indicator is provided which includes a transparent elongated cylinder visible to a user of the delivery device, the cylinder housing a piston slidable therein. The cylinder includes an inlet for the passage of a pressurized fluid therein and the piston is displaced so that the relative position of the piston and the cylinder visually indicates the relative fluid pressure in the transfer device. The pressure indicator may include a portion having an inner diameter larger than the portion of the cylindrical member in which the piston is disposed, and an outlet communicating with the enlarged diameter portion of the cylindrical member. As a result, when the fluid pressure is sufficient to move the piston to the enlarged diameter portion of the cylinder, fluid leaks through the piston and exits the cylinder through the outlet. Alternatively, the pressure indicator may be connected in parallel fluid communication with a pressure relief valve of a known construction.

In another aspect of the invention, the catheter is provided with a connector at its proximal end, with the connector being received within a central bore in the delivery device. The connector is provided with at least one detent to secure the connector in the central bore of the delivery device, which detent must be manually manipulated to enable the catheter to be released from the delivery device.

It is a further aspect of the present invention to provide a method of determining whether a therapy unit is present in a delivery device. The method comprises the following steps: encapsulating the treatment unit in a material having a known wavelength/reflectance ratio; illuminating light of different wavelengths into the area where the treatment unit is normally stored in the delivery device, either before or after introduction of the treatment unit into the catheter; measuring the reflectance of two reflected lights reflected from the conveyor; determining the wavelength/reflectance ratio of the reflected light; comparing the measured wavelength/reflectance ratio to a known wavelength/reflectance ratio; indicating whether the measured ratio is substantially the same as the known ratio.

In another aspect, the present invention provides a system for implementing the above method, the system comprising: a power source; a first light source optically coupled to the target site in the delivery device and emitting light having a first wavelength; a second light source optically coupled to the target site in the delivery device and emitting light having a second wavelength; a light sensor optically coupled to the target site in the delivery device, for measuring reflected light from the target site and generating a signal in response thereto; a window detector for determining whether the signal generated by the light sensor falls within a predetermined wavelength band corresponding to a signal generated by light having the first and second wavelengths reflected by the treatment unit; an illuminated indicator illuminates if the signal generated by the light sensor falls within the predetermined wavelength band.

Brief description of the drawings

FIG. 1 is a schematic view of an intraluminal radiation treatment system including a delivery device, a delivery catheter, and a connector connecting the two;

FIG. 2 is an exploded view of the transfer device of the present invention;

FIG. 2A is a cross-sectional view of the transfer device of FIG. 2 in an assembled state;

FIG. 3 is a cross-sectional view of the rear housing of the transfer device;

FIG. 4 is a bottom view of the rear housing of the transfer device;

FIG. 5 is a perspective view of the fluid lever;

FIG. 6 is a perspective view of the fluid control switch;

FIG. 7 is a bottom view of the fluid control switch;

FIG. 8 is a cross-sectional view of a housing of the delivery device, the housing including a quartz sleeve for receiving the radiation therapy unit;

FIG. 9 is an enlarged cross-sectional view of a portion of the rear housing of the transfer device interfacing with the seed cavity of the quartz sleeve;

FIG. 10 is a plan view of the distal face of the center housing;

FIG. 11 is a plan view of the actuator switch;

FIG. 12 is a plan view of the valve;

FIG. 13 is a plan view of the proximal face of the valve housing;

FIG. 14 is a plan view of the distal face of the valve housing;

FIG. 15 is a plan view of the proximal face of the flange housing;

FIG. 16 is a plan view of the release trigger;

FIG. 17 is a plan view of the release switch;

FIG. 18 is a top view of the release switch;

fig. 19 is a front housing proximal face plan view;

FIGS. 19A-19C illustrate the interaction of the release trigger and the release switch in the connector insertion trigger device;

fig. 20 is a front housing side view;

FIG. 21A is a schematic view of an intraluminal radiation treatment system embodying the present invention with the rear housing of the delivery device in an alternative configuration;

FIG. 21B is an exploded perspective view of the rear housing/fluid control switch of FIG. 21A;

FIG. 21C is a cross-sectional view of a delivery device in an assembled state with an alternative embodiment of the rear housing/fluid control switch of FIG. 21B;

FIG. 22 is a top view of the rear housing shown in FIG. 21B;

FIG. 23 is a side view of the rear housing shown in FIG. 21B;

FIG. 24 is a perspective view of the fluid control switch of FIG. 21B, showing the proximal side of the switch;

FIG. 25 is a perspective view of the fluid control switch of FIG. 21B, showing the distal side of the switch;

FIG. 26 is a plan view of the fluid control switch of FIG. 21B, showing the proximal side of the switch;

FIG. 27 is a plan view of the fluid control switch of FIG. 21B, showing the distal side of the switch;

FIG. 28 is a schematic view of an intraluminal radiation treatment system of the present invention;

FIG. 29A is a perspective view of another embodiment of the delivery device of the present invention further showing a syringe cartridge connected thereto;

FIG. 29B is a perspective view similar to FIG. 29A, except that the top half of the conveyor housing is removed to show the internal structure thereof;

FIG. 30 is a plan view of the conveyor housing shown in FIG. 29A;

FIG. 31 is an exploded perspective view of the conveyor shown in FIG. 29A;

FIG. 32A is a transverse cross-sectional view of the conveyor shown in FIG. 29A;

FIG. 32B is a longitudinal cross-sectional view of the delivery device shown in FIG. 29A;

FIG. 32C is an enlarged cross-sectional view of one of the internal components of the transfer device shown in FIG. 29A;

FIG. 32D is a longitudinal cross-sectional view of the transfer device shown in FIG. 29A, taken perpendicular to the cross-sectional view shown in FIG. 32B;

FIG. 33 is a side view of the conveyor shown in FIG. 30;

FIGS. 35A-35D illustrate a pressure indicator/pressure relief valve, and components thereof, which can be conveniently used in the delivery device of FIG. 29A;

FIG. 37 is a perspective view of selected internal components of the transfer device of FIG. 29A mounted on a support;

FIG. 38 is a perspective view of a release switch used in the transfer device of FIG. 29A;

FIGS. 39A-39B are perspective views of an assembly of needle valves for use in the delivery device of FIG. 29A;

FIGS. 40A-40D illustrate a needle/release switch safety interlock used in the delivery device of FIG. 29A;

FIGS. 41A-41E illustrate a catheter connector and its various accessories as used in the present invention;

FIGS. 42A-42D show a catheter employed in the present invention and a cross-sectional view thereof (FIG. 42D);

FIG. 45 is a logical block diagram of a system for treatment unit verification that can be effectively employed with the delivery device of FIG. 29A;

FIG. 46A-1, FIG. 46A-2; FIG. 46B; and FIG. 46C-1, FIG. 46C-2, and FIG. 46C-3 are circuit block diagrams for performing the functions presented in the logic block diagram of FIG. 45;

FIG. 47 is a plan view of a housing of another embodiment of the transfer device;

FIG. 48 is a perspective view of the transfer device of FIG. 47 with the top half of the housing removed to show internal details thereof;

FIG. 49 is an end view facing the distal end of the delivery device shown in FIG. 47;

FIG. 50 is an exploded perspective view of the conveyor shown in FIG. 47;

FIGS. 51A and 51B are longitudinal cross-sectional views of the delivery device of FIG. 47;

FIG. 51C is a transverse cross-sectional view of the conveyor shown in FIG. 47;

FIG. 52 is an exploded perspective view of a pressure indicator gauge and pressure relief valve used in conjunction with the delivery device shown in FIG. 47;

FIG. 53 is a cross-sectional view of the pressure indicator gauge and pressure relief valve of FIG. 52, schematically illustrating the passage of fluid therethrough;

FIGS. 54A and 54B are perspective views of a latch member used in conjunction with the transfer device of FIG. 47;

FIG. 55 is a perspective view of a sear used with the conveyor of FIG. 47;

56A, 56B and 56C illustrate an assembled latch mechanism including a latch body member in perspective view, a latch sear in plan view and a latch button in cross-sectional view, respectively;

FIGS. 57A and 57B show, in perspective and cross-sectional views, respectively, a skirt connector used in conjunction with a catheter connector;

FIG. 57C is a proximal cross-sectional view of the catheter connector showing an intermediate plug member;

FIG. 58A is a plan view of a catheter in which the present invention is used;

FIG. 58B is an enlarged transverse cross-sectional view of the catheter shown in FIG. 58A;

FIG. 58C is an enlarged longitudinal cross-sectional view of the distal end of the catheter shown in FIG. 58A;

FIG. 59 is a plan view of a seed array of therapeutic units for use in the present invention;

FIG. 60 is a logical block diagram of a treatment unit verification system for use with the delivery device of FIG. 47;

FIG. 61A-1, FIG. 61A-2, FIG. 61A-3; FIG. 61B; FIG. 61C-1, FIG. 61C-2 is a circuit block diagram for performing the functions set forth in the logic block diagram of FIG. 60;

FIG. 61D is a schematic diagram of a power panel used in the treatment unit testing system of FIGS. 60 and 61A-61C;

FIGS. 62A-62C are printed circuit boards showing the mechanical layout profile applied to the treatment unit inspection system of FIGS. 60 and 61A-61D;

FIG. 63A is a schematic diagram showing the electrical connections between the various parts of the treatment unit inspection system;

FIG. 63B is a circuit diagram, which is equivalent to FIG. 63A.

Detailed Description

Figure 1 illustrates an intraluminal radiation treatment system 10 of the present invention which includes a delivery device 12, a delivery catheter 14 and a connector 16 for securely connecting the delivery catheter 14 to the delivery device 12. The delivery catheter 14 and connector 16 are substantially as described in the above-identified, co-pending patent application, the contents of which are incorporated herein by reference.

The function of the delivery device 12 is to house and shield a radiation treatment source set (not shown), which may include a non-radioactive marker seed, and to control the fluid flow direction to fill the delivery device 12 and the catheter 14 and to effectively deliver and retrieve each radiation treatment unit.

The transfer device 12 is shown in a perspective exploded form in fig. 2 and consists of three main assemblies: a rear housing and fluid control switch assembly 18, a middle housing and actuator switch/shuttle valve assembly 20, and a front housing 22. The rear housing and fluid control switch assembly and the middle housing and actuator switch/shuttle valve assembly disclosed in this patent application are interchangeable with the corresponding parts disclosed in the above-identified, co-pending patent application.

The rear housing 18 includes a cylindrical member 24, preferably made of polycarbonate, which is provided with through holes 26 for receiving two screws 28 for connecting the rear housing 18 and the middle housing 20. The threads of the screw 28 may directly engage the polycarbonate material of the center housing 80, or the internal threads of the through bore 26 may receive a helical, spiral-shaped wire insert that mates with the threads of the screw 28. Alternatively, the bore of the middle housing 80 that mates with the screw 28 may be provided with an internally threaded metal insert (not shown) that may be secured within the bore, for example, by ultrasonic welding, such that the threads of the screw 28 engage the internal threads of the metal insert, thereby providing a more durable connection between the rear housing 18 and the middle housing 80.

The cylinder 24 is provided with a cylindrical recess 30 for receiving a fluid control switch 44, the latter of which will be discussed in more detail below. The cylinder 24 includes two Luer connectors or Luer fittings 32, 34. the Luer fittings 32,34 are preferably made of a polycarbonate and are secured to the cylinder 24 with an ultraviolet curable adhesive (UV-cure adhesive). The luer fittings 32,34 may be partially or fully recessed into the rear housing 18. The luer fitting 32 is seated in a recess 32a in the cylinder 24 and communicates with a fluid inlet passage 36 (best seen in fig. 3). The luer 32 is connected to a fluid or gas filled device (not shown) for hydraulically or pneumatically delivering and retrieving the radiation therapy source sets from the delivery catheter 14.

The luer 34 is seated in a recess 34a in the cylinder 24 and communicates with a fluid outlet passage 38 (see fig. 4). Luer 34 may be selectively connected to a fluid collection bag or trough (not shown). The cylinder 24 also includes a fluid return passage 40 (see fig. 4) and a seed delivery passage 42 (see fig. 3). Each of the passages 36,38,40 and 42 communicates with the cylindrical recess 30.

The fluid control switch 44 may selectively provide communication between the various channels 36,38,40, and 42 for delivering and/or retrieving the radiation therapy unit and the identification seed from the delivery catheter 14. To facilitate manipulation of the fluid control switch 44, a paddle-shaped lever 46 is secured to the fluid control switch 44 and the cylindrical member 24 by a set screw 48 which passes through a central bore in the lever and through the switch 44 and into the cylindrical housing 24. The bottom of set screw 48 abuts a stop screw 49 to limit the movement of screw 48 and prevent screw 48 from being loosened by operation of switch 44. The locking cap 50 closes the central opening of the lever 46. As best seen in FIG. 5, the fluid control handle 46 is provided with a paddle-shaped portion 52 that may be ergonomically shaped to make it easier for a user to manipulate the fluid control switch 44.

The head of the set screw 48 may optionally be notched to allow a locking pin (not shown) to be inserted therebetween. Such locking pins prevent rotation of the set screw 48 so that counterclockwise rotation of the fluid control handle 46 does not loosen the screw 48. A shallow bore is provided in the fluid control stem 46 at the head of the set screw 48 for receiving the locking pin.

To limit the extent to which the fluid control switch 44 can be rotated, a fluid control notch 54 (see fig. 6, 7) is provided in the bottom of the switch 44 and cooperates with an adjustment pin 56 (see fig. 2) that is secured in a hole in the recessed area of the rear housing 18. To enable the switch to be reliably in the "off", "delivery" and "return" positions, etc., the fluid control switch 44 is also provided with three recesses 58 (see fig. 6) which cooperate with a detent ball 60 and spring 62 (see fig. 2) which is seated in a short bore 64 (see fig. 3) in the cylinder 24.

As best seen in FIG. 7, the bottom of the fluid control switch 44 is provided with a C-shaped connector passage 66 and an oval connector passage 68. The control switch 44 may be released at the C-shaped and elliptical connector passages 66,68 to seat o-rings 70 and 72, respectively, which seal the connector passages 66,68 against the recess 30. To further prevent fluid from escaping around the fluid control switch 44, an O-ring 74 (see FIG. 6) is disposed in an O-ring channel 76 formed around the periphery of the fluid control switch 44 and an O-ring 78 is disposed in an O-ring channel formed around the periphery of the distal opening of the switch 44. The O-rings 70,72,76 and 78 are preferably made of nitrile rubber or ethylene propylene.

In operation, when the fluid control switch 44 is in the "delivery" position, both the fluid injection passage 36 and the seed delivery passage 42 are in communication with the C-shaped connector passage 66. While the fluid return passage 40 and the fluid discharge passage 38 communicate with the oblong connector passage 68. Thus, fluid may flow through the fluid injection passage 36 and into the seed delivery passage 42 through the C-shaped connector passage 66. Fluid bypassing the treatment unit passes to the distal end of the delivery catheter 14 and then returns to the fluid return channel 40 and flows through the oblong connector channel 68 into and through the discharge channel 38.

When the fluid control switch 44 is in the "back" position, both the fluid injection passage 36 and the fluid flow return passage 40 are aligned through the C-shaped connector passage 66. At the same time, the seed transport passage 42 and the fluid discharge passage 38 are aligned by the oblong connector passage 68. As a result, fluid may flow through the fluid injection passage 36 into the C-shaped connector passage 66 and then through the fluid return passage 40. When the treatment unit is returned from the distal end of the catheter to the delivery device 12 by hydraulic pushing, fluid can flow from the seed delivery passageway 42, through the oblong connector passageway 68 and into the fluid discharge passageway 38.

When the fluid control switch 44 is in the "off" position, only the fluid injection passage 36 is aligned with the C-shaped connector passage 66. Thus, there is no outlet for fluid flowing from the fluid injection passage 36 into the C-shaped connector passage 66.

The delivery device 12 preferably includes a pressure relief valve (not shown) so that the system 10 does not create an overpressure. Once the pressure exceeds a predetermined value, the pressure relief valve may open to allow fluid in the system 10 to escape. When the pressure in the system returns to a safe level, the pressure relief valve closes. One form of pressure relief valve is spring operated such that the spring is compressed to open the pressure relief valve when the fluid pressure is greater than a predetermined value and the pressure relief valve is closed by the spring when the fluid pressure drops below the predetermined value. In addition, the delivery device 12 is preferably provided with an accumulator (not shown) or similar device to allow a sufficient amount of pressure to be exerted on the radiation therapy source set and marker seeds when they are at the distal end of the catheter 14 so that they do not become detached from the distal end of the catheter 14 and the treatment site during radiation therapy. The accumulator may also be used to maintain a sufficient amount of pressure on the treatment unit and marker seed so that they remain entirely within the lumen of the quartz cannula 84 and visible to the user when not being used for radiation therapy.

Attached to the distal end of rear housing 18 is a middle housing and actuator switch/shuttle valve assembly 20. Proper alignment between the rear housing 18 and the middle housing and the actuator switch/shuttle valve assembly 20 may be ensured by alignment pins (not shown). The assembly 20 includes a central housing 80 having a central bore 82 (see fig. 8) for receiving a quartz sleeve 84 extending the length of the central housing 80, in which the radiation therapy source set or seeds are stored.

The middle housing 80 is cylindrical and preferably made of transparent litxon (Lexan) or transparent polycarbonate. The quartz sleeve 84 is preferably made of natural or synthetic quartz or quartz glass (fused silica), or other materials containing natural or synthetic fused silica. A lumen 86 is provided along the entire length of the quartz sleeve 84 in which the radiation therapy source set and marker seeds are stored when the seeds are not being delivered to the treatment site. The quartz sleeve 84 is used to shield the radiation emitted by the radiation therapy source set so that the delivery device 12 can be safely operated. The quartz material does not break upon storage of radioactive seeds and retains its transparency so that the seeds can be visually inspected. The quartz rod needs to be thick enough to shield 90% of the radioactivity. In practice it was found sufficient to have a quartz sleeve thickness of 1 cm.

To better understand the presence of the source seeds and marker seeds in the quartz sleeve 84, the diameter of the sleeve should be uniform without any steps, and without any O-rings placed thereon. In this way, the quartz sleeve is clearly visible over its entire length. The lower half of the quartz sleeve 84 is covered with a white membrane, preferably made of vinyl or taverk (Tyvek ), to create a contrasting background for the radioactive source seeds. Alternatively, or in addition, a quartz sleeve 84 may be wrapped around its outer circumference or may have a magnifying device placed on its upper portion to provide better visual access to the radioactive seeds. In addition, a light source can be used to better observe the radioactive source and the marking seeds.

As best seen in fig. 3 and 9, a rear housing insert 88 with a through bore forms an intermediate coupling between the rear housing 18 and the middle housing 20, allowing the seed transport passage 42 and the lumen 86 of the quartz sleeve 84 to communicate through the bore 90 of the insert 88. The lumen 90 is L-shaped to prevent movement of the treatment unit into the rear housing 18 while ensuring fluid communication between the rear housing lumen and the quartz lumen.

A through small bore 92 (see fig. 10) is provided in the middle housing 80 off-center and is a continuation of the liquid return passage 40 in the rear housing 18. Fluid leakage at the junction between the return passage 40 in the rear housing 18 and the return bore 92 in the middle housing 80 is avoided by an o-ring (see fig. 2) preferably made of nitrile rubber or ethylene propylene.

An actuator switch 96 is provided at the distal end of the middle housing 80 that rotates a shuttle valve 98 to operate the system. The actuator switch 96 can be used in two positions: "connect/fill" and "deliver/retrieve". The connected/inflated state may be used to place the connector 16 in communication with the transfer device 12 (see fig. 1). After connection, the connected/inflated state may be used to prime the delivery device 12 and catheter 14 without delivering the radiation therapy source set.

The delivery/retrieval state is used to deliver the radiation therapy source set and the identification seed to the distal end of the catheter 14 and retrieve the radiation therapy source set and the identification seed therefrom. The delivery/retrieval state of the actuator switch 96 is not accessible unless the connector 16 is locked in the transfer device 12. This avoids inadvertent delivery of the radiation therapy source set to any location other than the delivery catheter 14. To this end, the distal face of the middle housing 80 is provided with a recessed region 100 (see fig. 10) that is substantially square U-shaped. The recess 100 receives a detent pin 102 (see fig. 2) to positively lock the actuator switch 96/shuttle valve 98 in place for both conditions.

The actuator switch 96 is made of a hard plastic material, such as, for example, Astalr (Acetal) or Delrin (Delrin). The actuator switch 96 is provided with a top portion 96a (see fig. 11) having a concave shape so that the user can operate the switch with only one thumb or one finger. The actuator switch 96 is also provided with two slightly arcuate arms 96b extending outwardly and downwardly from a central portion thereof. At the bottom of the switch 96 are two rectangular legs 96c, each of which has a through hole 96d for receiving a locating pin 102. A hollow is formed between the legs 96c and the middle of the switch 96 for seating the top of the valve 98 and a compression spring 104 (see fig. 2).

The shuttle valve 98 is made of plastic, such as aspartame, or clear polycarbonate, and has sufficient thickness to ensure rigidity during its rotation. The shuttle valve 98 has a valve body portion 106 (see fig. 12) with a shoulder that tapers inwardly to an arcuate base. The valve body 106 is provided with an aperture 107 for seating a compression spring 105 (see fig. 2) which biases the shuttle valve 98 toward the connected/charged condition. Extending upwardly from the body 106 of the valve 98 is a neck 108 which is provided with an aperture 110 for receiving the compression spring 104. The neck 108 also has a slot 112 for receiving the pin 102. The valve 98 is provided at its bottom with a through hole 114 for receiving a rotation pin 116 (see fig. 2) so that the valve 98 can rotate about the rotation pin 116. The valve 98 is further provided with a hole 118 between the dowel bore 114 and the dowel slot bore 112, which is large enough to allow the treatment unit to pass therethrough. An O-ring groove 120 is provided on each side of the valve for receiving an O-ring 122 (which surrounds the proximal opening of the seed hole) and an O-ring 124 (which surrounds the distal opening of the seed hole). The position of the O-rings 122,124 (see FIG. 2) is such that they do not travel over the edges of any other components as the actuator switch/shuttle valve moves between its various positions, thereby reducing the wear of the O-rings and smoothing operation of the valve 98.

In operation, the compression spring 104 presses the actuator switch 96 away from the shuttle valve 98. When the actuator switch 96 is pressed downwardly against the force of the compression spring 104, the detent pin 102 moves toward the bottom leg of the U-shaped recess 100 in the center housing 80 and the flange housing, thereby moving the actuator switch 96 and the shuttle valve 98 between the two positions.

The shuttle valve 98 is secured to the distal end of the middle housing 80 by a valve housing 126. As best shown in fig. 13, the proximal end of the valve housing 126 is provided with a recessed area 128 in the general shape of the shuttle valve 98 and a substantially rectangular opening 129. When the valve 98 is in the recessed area 128, the neck 108 extends out of the valve housing 126. The valve housing 126 is provided with a seed lumen 130 that is chamfered at both the proximal and distal ends to facilitate delivery of the treatment unit (seed lumens in other housings may also be chamfered at their ends to facilitate delivery of the treatment unit).

The distal end of the valve housing 126 (best seen in fig. 14) is provided with a circular recessed area 132 having an inverted tapered edge around the seed cavity to center the connector 16. In order to center the valve housing 126 with the center housing 80 and the flange housing 146, the valve housing 126 is further provided with holes 136 (see FIG. 2) for positioning screws and a centering hole 140 (see FIG. 2) for positioning the positioning pins 142, 144. The valve housing 126 is also provided with a fluid return passage 148 (which is a continuation of the fluid return passage 92 in the middle housing 80) and an annular groove 150 at the proximal end of the valve housing 126 for receiving an o-ring 152 (see fig. 2). The bore 154 at the proximal end of the valve housing engages the distal end of the rotating pin 116 of the shuttle valve 98.

The flange housing 146 has an enlarged central opening 160 for receiving the connector 16, which is flared on the proximal side of the flange housing 146 for receiving the o-ring 134 (see fig. 2). A rectangular hole 161 penetrates the flange housing 146. The flange housing 146 is provided with a fluid return passage 162 (which is a continuation of the fluid return passage 148 in the valve housing 126) having an annular o-ring groove around its proximal end for seating an o-ring 164 (see fig. 2). There is also provided an alignment hole for locating alignment pin 144 to align flange housing 146 with valve housing 126, and another alignment hole for locating alignment pin 166 to align flange housing 146 with front housing 156.

The cutouts in the distal face of the flange housing 146 and in the proximal face of the front housing cooperate to receive the release button 168, release switch 170 and release trigger 172, which in combination, position and lock the connector 16 in the transfer device 12 and release the connector 16 from the transfer device 12. The interaction between the release button 168, release switch 170 and release trigger 172 will be described in detail below.

The release trigger 172 (see fig. 16) includes a generally rectangular trigger body 172a with two legs 172b extending therefrom. A parabolic chamfer 172c is provided on the distal end of the trigger 172 to form an edge between the legs 172 b. The top of the release trigger 172 is provided with a shallow bore 172d for receiving one end of a compression spring 174 (see fig. 2).

The release switch 170 (see fig. 17) includes an elongated rectangular switch body 170a having an arcuate notched ramp 170b at one end and a projecting arm 170c (see fig. 18) at the other end. The protruding hip 170c is provided with a hole 170d for receiving a positioning pin 176 (see fig. 2). The release button 168 is secured to the release switch 170 by a screw 178 (see FIG. 2) that is received in a hole 170e in the release switch 170. Alternatively, the release button 168 may be formed as a unitary piece with the release switch 170.

The front housing 156 forms the distal portion of the transfer device 12 and includes a central bore 180 for receiving the connector 16 (see fig. 19). The central bore 180 is provided with chamfered portions at 181 (see fig. 20) to receive two o-rings that mate with the exterior of the connector 16 (to seal the connection between the connector 16 and a fluid return passage 184 in the front housing 156) within the connector lock to the transfer device 12. The front housing 156 is provided with two screw holes 182 for receiving screws 138 which secure the front housing 156, the flange housing 146 and the valve housing 126 to the middle housing 80. As described above, the bores in the middle housing 80 for receiving the screws 138 may be selectively inserted into helical, spiral wire inserts or threaded metal inserts to provide a more secure connection. The front housing 156 is also provided with a fluid return passage 184 (which is a continuation of the fluid return passage 162 in the flange housing 146) having an annular O-ring groove around its proximal opening for seating an O-ring 186 (see FIG. 2). The holes provided on the proximal face cooperate with the dowel pins 166 to ensure that the front housing 156 is centered with the flange housing 146.

Turning now to the operation of the actuator switch/shuttle switch, when the valve 98 is in the closed position (the connector 16 is not connected to the transfer device 12), the release switch 170 rests against a compression spring 190 (see FIG. 2) with a leg 172b of the release trigger 172 engaging the uppermost portion of the ramp 170b of the release switch 170 to press the release switch downwardly against the compression spring 190 (see FIG. 19A). In this condition, the release button 168 is then fully recessed in the opening between the flange case 146 and the front case 156. The ends of the locating pin 176 pass through openings 129 and 161 of the valve housing 126 and flange housing 146, respectively, at the bottom of opening 129,161 and are located adjacent to the valve 98 to prevent the valve from turning and entering the seed transport state.

When the connector 16 is inserted into the central bore 180 of the front housing 156, the proximal end of the connector 16 contacts the chamfered notch 172c of the release trigger 172, causing the trigger 172 to be pushed upward while compressing the spring 174 (see FIG. 19B). As the release trigger 172 moves away from the release switch 170, the movement of the release switch 170 is no longer impeded and the release switch, which is biased by the compression spring 190, moves upward until the arcuate ramp 170b engages the undercut of the connector 16. This locks the connector 16 in the transfer device 12. When the release switch 170 is moved to unlock the connector 16, the release button 168 is moved out of its recessed area to visually confirm that the connector 16 is locked in the transfer device 12 (see fig. 19C). At the same time, the locating pin 176 is moved over the opening 129,161 so that it no longer prevents the valve 198 from entering the seed transport state.

The actuator switch 96 can now be moved from the connected/filled state to the seed transport state by pushing the actuator switch 96 downward, pushing the detent pin 102 down to the bottom of the slot 100 (in the center housing 80) and the slot 158 (in the flange housing 146). While maintaining downward pressure on the actuator switch 96, a horizontally directed force is applied to the actuator switch 96 to move the locating pin 102 through the horizontal slot of the recess 100,158 to another vertical slot. The switch 96 is then released and the detent pin 102 moves up to the top of the vertical slot, placing the switch 98 in the seed transport position. When the actuator switch 96 enters the seed transport state, the valve 98 is positioned such that a portion of the valve 98 now occupies the same space occupied by the alignment pin 176 that was in the connected/filled state.

To disengage the connector 16 from the delivery device, the actuator switch 98 is moved to the connected/filled state after all treatment units and identification seeds have been returned to the quartz sleeve 84. Once the actuator switch 98 is in the connected/charged state, the release button 168 is pushed inward, pushing the release switch 170 downward against the spring 190. The locating pin 176 is simultaneously moved to prevent the valve gate 98 from moving back to the seed transport position. The connector 16 can then be removed from the transfer device by hand. Removal of the connector 16 may cause the release trigger 172 to lower under the urging of the spring 174 to reposition its leg 172b forward of the ramp 170b, returning the release button 168, release switch 170 and release trigger 172 to their starting positions.

The release button 168 is not activated when the actuator switch 96 is in the seed transport state. In the seed transport position, the valve 98 is positioned such that it prevents the positioning pin 176 from moving downward. Because the alignment pin 176 is attached to the release switch 170, downward movement of the release switch 170 is also prevented and the arcuate ramp surface 170b cannot be disengaged from the connector 16.

Referring now to fig. 21-27, there is shown an additional rear housing/fluid control switch embodiment employed in the transfer device 12 of the present invention. As shown in fig. 21B, the rear housing 200 is substantially cylindrical and includes two axial through holes 202 for receiving two screws (e.g., the screws 28 in fig. 2) to secure the rear housing 200 to the middle housing. The rear housing 200 is provided with two recesses 204,206 for receiving luer connectors or connectors similar to the connectors 32,34 shown in fig. 2. Such luer connectors may be adhesively secured in the recesses 204,206. The luer fitting may be partially or fully recessed in the rear housing 200. The luer connector disposed in the recess 204 is preferably adapted for connection to a fluid or gas filled device (not shown) for hydraulically or pneumatically delivering the radiation therapy source set and marker seeds to and from the delivery catheter 14. The luer fitting secured in the recess 206 is then connected to a fluid collection bag (not shown).

Near the distal end of the rear housing 200 is a cylindrical bore 208 for receiving a fluid control switch 210, as will be described in more detail below. The diameter of the cylindrical bore 208 is slightly smaller than the maximum diameter of the fluid control switch 210 so that the fluid control switch 210 fits tightly within the bore 208. A fluid inlet passage 212 connects the dimple 204 with the cylindrical bore 208 (see fig. 22); a fluid exhaust passage 214 connects the dimple 206 with the cylindrical bore 208 (see fig. 23); fluid return/seed retrieval passage 216 connects cylindrical bore 208 with opening 218 at the distal end of rear housing 200 (see fig. 22 or 23); fluid return/seed retrieval passage 220 connects cylindrical bore 208 with a central distal opening 222 (see fig. 22 or 23) provided with a rear shell insert 224 (similar to insert 88 in fig. 9).

The fluid control switch 210 is a solid cylinder, preferably made of white or clear Teflon (Teflon) material, so that the cylinder 210 can smoothly move the switch 210 in the central bore 208 to provide four fluid passages (to be described later) for selectively connecting the connecting passages 212 and 214 with the passages 216 and 220. The switch 210 has a rectangular cutout 226 in an upper portion thereof for receiving a handle 228, the rectangular cutout being sized so that a distal end 230 of the handle 228 fits snugly therein.

The handle 228 is enlarged at its distal end 230 so that it has a cantilevered portion or step 231. When the distal end 230 of the handle 228 is fitted into the rectangular cutout 226 of the fluid control switch 210 and the fluid control switch 210 is seated in the cylindrical hole 208 of the rear housing 200, the entire cantilever portion 231 is seated in the periphery of the switch 210, and the cantilever portion 231 abuts against the side wall of the central hole 208, which prevents the handle 228 from coming out of the cutout 226, ensuring that the handle 228 is fixed in the switch 210.

The fluid control switch 210 is provided with four passages 242,244,246 and 248 for selectively connecting the fluid inlet passage 212 and the fluid outlet passage 214 with the fluid return/seed withdrawal passage 216 and the fluid return/seed withdrawal passage 220. As best shown in fig. 26 and 27, the fluid control switch 210 includes a seed delivery passage 242, a fluid return passage 244, a seed retrieval passage 246 and a fluid return passage 248.

In operation, when the fluid control switch 210 is in the "transport" position, both the fluid inlet passage 212 and the seed transport passage 220 in the rear housing 200 are in communication through the seed transport passage 242 in the fluid control switch 210. At the same time, the fluid discharge passage 214 and the fluid return/seed retrieval passage 216 in the rear housing 200 communicate through the fluid return passage 248 in the fluid control switch 210. In this manner, fluid may be passed from, for example, a syringe, through the fluid inlet passageway 212 and the seed delivery passageway 242 in the switch 210, and into the seed delivery passageway 220 to advance the treatment unit to the distal end of the delivery catheter 14. Fluid that bypasses the treatment unit passes to the end of the delivery catheter and returns to the fluid return/seed retrieval channel 216 and may flow through the fluid discharge channel 214 into, for example, a fluid collection bag via the fluid return channel 248 in the fluid control switch 210.

When the fluid control switch 210 is in the "retrieve" position, both the fluid inlet passage 212 and the fluid return/seed retrieval passage 216 in the rear housing 200 are in communication through the seed delivery passage 246 in the fluid control switch 210. At the same time, both the fluid discharge passage 214 and the seed feed passage 220 in the rear housing 200 communicate through the fluid return passage 244 in the fluid control switch 210. As a result, fluid may flow through the fluid outlet passage 212 into the seed retrieval passage 246, through the fluid return/seed retrieval passage 216 into the catheter, thereby hydraulically pushing the treatment elements out of the seed delivery passage 220, through the fluid return passage 244 into the fluid outlet passage 214, and out of the delivery device.

When the fluid control switch 210 is in the "off position, none of the passages 212,214,218,220,242,244,246 and 248 are in communication with each other. In this way, no fluid can flow out of the fluid inlet passage 212.

The fluid control switch 210 is provided with a groove 250 for seating an o-ring 252 to prevent the cylindrical bore 208 from escaping (see fig. 24, 25). The fluid control switch 210 is also provided with three enlarged diameter regions, generally indicated at 254, to prevent fluid passages 242,244,246 and 248 from interfering with one another. These enlarged diameter regions correspond to the openings of the passages 242,244,246 and 248 and form a tight seal around the fluid openings. Alternatively, an o-ring may be used instead of the enlarged diameter region.

An oblong opening 232 (see fig. 27) is provided at the distal end of the fluid control switch 210 and extends radially along the surface of the switch 210 such that when the switch 210 is placed in the cylindrical bore 208, the oblong opening 232 is aligned with a short through bore 234 in the rear housing. The oblong opening 232 extends into the interior of the fluid control switch 210 and terminates with three recesses 236 that cooperate with a compression spring 238 and a detent pin 240 (see fig. 21B) to assist in the positioning of the fluid control switch 210 (similar to the compression spring 62 and detent ball 60 shown in fig. 2). The end of the oblong opening 232 cooperates with the stop pin 240 to act as a stop to limit the extent to which the fluid control switch 210 can be rotated.

The detent pin 240 is provided with a spherical end that seats in the recess 236. In the "off" position, the detent pin 240 is seated in the central recess. As the fluid control switch 210 is moved either to the "delivery" position or to the "retrieval" position, the middle pocket is also moved away from the detent pin 240, and either of the other two pockets will move toward the detent pin. As the switch 210 and recess rotate, the detent pin is pushed back against the compression spring 238. When one of the end pockets is aligned with the brake pin, the spring force of the spring urges the brake pin 240 forward so that the ball portion of the brake pin 240 seats in the pocket. The detent pin always secures the switch 210 in the rear housing 200 because it does not move out of the opening 232 when it moves out of the recess during rotation of the switch 210.

Referring now to fig. 29-33, an improved delivery device 300 is shown for use in conjunction with the intraluminal radiation treatment system of the present invention for operating and delivering treatment units. Unlike the previously described delivery devices, the delivery device 300 includes an ergonomically designed profile that is more easily grasped by the user. In addition, the various internal components of the transfer device 300 are easy to manufacture and assemble. The delivery device 300 also has added or improved safety features such as therapy unit detection circuitry and displays, fluid pressure indicators/relief valves, and a catheter connector/seed or needle valve interlock, all of which will be described in greater detail subsequently.

Referring now to the exploded view of fig. 31, it can be seen that the transfer device comprises a two-part housing, half shells 302a and 302b, which house a support 304 on which the various components of the transfer device 300 are mounted. The half shell 302a is provided with: a magnifying window 306 to allow visualization of a quartz cannula 308 having a lumen 308a for a therapeutic seed (not shown); an indicator light source or "indicator apparatus" comprising light emitting diodes 310a and 310b (see FIG. 30) which indicate whether the therapeutic seeds are stored in a quartz sleeve or elsewhere in the delivery device and its associated catheter; a power button 312 for activating a Light Emitting Diode (LED) seed detection/indicator system; a pressure indicator window 314 for visually displaying the pressure level of the fluid in the treatment system; and a fluid control button 316 (which functions similarly to the fluid control handle 44 or 228 described above) for operating the fluid control switch. Along the side of half shell 302a is a release button 318 (which functions similarly to release button 168 described above) for the catheter connector and a sliding valve actuator switch 320 that covers release button 318 to prevent inadvertent release of the catheter connector when a therapeutic seed is delivered or placed in the catheter. The transfer device 300 is also provided with a compartment 319 (see fig. 33) at its proximal end for receiving a fluid collection bag (not shown).

Referring now to fig. 29A and 29B, the delivery device 300 is shown with a removable syringe 322 that provides pressurized fluid for hydraulically delivering and retrieving the therapeutic seeds employed by the present system. The syringe 322 is connected to the transfer device by a luer lock 324 and is supported on the transfer device by a saddle having two offset arms 326a and 326b (best seen in fig. 30 and 31) that extend from the housing halves 302a and 302b, respectively, and surround the barrel 322a of the syringe 322 to securely hold the syringe on the transfer device. As shown in fig. 29A and 29B, the syringe 322 is held in place at an angle to the longitudinal axis to facilitate easier manipulation of the syringe plunger 322B.

As described above, the internal components of the transfer device 300 are separately manufactured and mounted on the carrier 304, where they are preferably connected together for fluid communication by polyethylene tubing (not shown) and Barbed Connectors (e.g., 328 (FIG. 31)). This configuration allows the present delivery device to be simpler, less expensive to manufacture, and easier to assemble than the previous embodiments, where, for example, the housing members (and their respective fluid passageways) and fluid control switches are machined from a single solid piece of material, and the pieces must be joined together. For example, rather than custom manufacturing the switches 44 (fig. 1, 2, 6, 7) and 210 (fig. 21B, 24-27) and their respective mating rear housings 18,200, the fluid control switch 330 of the transfer device 300 may include a standard four-port valve body, such as a 7017KV type valve member, manufactured by Kloehn Co.

Referring now to fig. 29B, 31 and 37, the support 304 of the transfer device 300 also supports a pressure indicator/pressure relief valve, generally indicated at 332, which is visible through a pressure indicator window 314 in the half shell 302 a. The pressure indicator/pressure relief valve 332 is in fluid communication with the syringe 332 and is designed to allow for easy visual reading of the relative fluid pressure values in the treatment system and to release fluid to the reservoir when the fluid pressure exceeds a predetermined maximum value (e.g., 100 pounds per inch), thereby ensuring that the fluid pressure does not reach a level that could damage the delivery device or its associated catheter.

Referring now to fig. 35A-35D, the pressure indicator/relief valve includes a cylinder 334 having an inlet port 336 in fluid communication with the syringe 322. The cylinder 334 has a stepped inner diameter, a small diameter portion 338a having a diameter of, for example, 0.375 inch, and a large diameter portion 338B having a diameter of, for example, 0.399 inch (see fig. 35A and 35B). The cylinder 334 houses: a piston 340 sized to fit the small diameter portion 338a of the cylinder 334; and a spring 342 disposed between the piston 340 and the end wall of the large diameter portion 338b of the cylinder member. The spring rate and length of the spring 342 are selected to retain the piston 340 within the small diameter portion 338a of the cylinder 334 until the fluid pressure reaches a predetermined maximum value. When the spring 342 is sufficiently compressed by the fluid pressure to force the piston 340 into the large diameter portion 338b of the cylinder 334 (e.g., when the pressure reaches 100 pounds per inch), fluid passes around the piston, into the large diameter portion 338b of the cylinder 334, and out the exhaust port 344 which is in fluid communication with the large diameter portion 338b of the cylinder 334. Once the fluid pressure in the system is below a predetermined maximum, the spring 342 pushes the piston 340 back into the small diameter portion 338a of the cylinder 334.

As shown, the piston 340 is comprised of two portions 340a and 340b that cooperate to form a gapped interface for seating a seal (not shown) that ensures fluid-tight contact between the piston 340 and the small diameter portion 338a of the cylinder 334. The piston may be made of white delrin material and the Seal may be an annular Seal such as that available from Bal Seal engineering Company of Santa Ana (Santa Ana), california, model number 410 MB-010-G-316. The cylinder 334 may be made of a clear polycarbonate with a finished inside diameter and index markings (not shown) on its outside that are visible through the pressure indicator window 314. The indexing marks allow the user to visually read the fluid pressure values in the system based on the relative position of the piston 340 in the cylinder 334. Additionally, the Spring 342 is preferably stainless steel, such as, for example, a Spring available from Lee Spring Company, Inc. of Brooklyn, N.Y., having the supply designation LCM-110E-13-S, Standard series. Of course, various other pressure gauges and pressure relief valves known in the art may be used in place of the spring-loaded piston and cylinder arrangement described above.

As with the previous embodiment, the delivery device 300 also includes a release trigger/release switch mechanism 350 (see FIG. 31) for positioning and locking the catheter connector in the delivery device (similar in configuration and operation to the release trigger 172/release switch 170 shown in FIGS. 16-19 and described above). The delivery device 300 also includes a needle valve 352 at the distal end of the quartz seed sleeve 308 that seals off the seed lumen to prevent the therapeutic seed from exiting the delivery device while also allowing fluid to flow through the seed lumen, for example, to fill the system. However, the delivery device 300 is provided with a safety interlock mechanism 354 (best seen in FIG. 40A) between the release trigger/release switch mechanism 350 and the needle valve 352 that prevents the release switch from being depressed (and thus prevents the user from moving the catheter connector out of the delivery device) if the needle valve is moved back to a position that allows the therapeutic seed to pass through the seed lumen.

Referring now to fig. 29B, 31, 32B and 32C, a single assembly 356 is shown supporting the release trigger/release switch mechanism 350 and needle valve mechanism 352 described above, as well as the quartz sleeve 308 and seed check system (described in more detail below) on the support 304. Similar to the release switch 170 described above, the release switch 358 (see FIG. 38) includes a switch body 358a, preferably made of Delrin material, having an arcuate notched ramp 358b at one end and a release button 318 (see FIG. 31) secured by a screw 360 at the opposite end. Alternatively, release button 318 may be formed as a unitary piece with release switch 358. As described above with respect to the release switch 170 and release trigger 172, the arcuate cutout ramp 358b of the release switch 358 engages the outer circumference of the recessed portion 362 of the catheter connector 364 (see FIG. 41) to lock the connector in the delivery device. Depressing the release switch 358 releases the arcuate cutout ramp 358b from the catheter connector 364 so that the connector can be removed from the delivery device.

As shown, the needle valve 352 (see FIGS. 39A and 39B) is preferably made of stainless steel and has a T-shaped configuration including a single enlarged valve body portion 352a terminated by an elongated cylindrical stem member 352B. A transverse head 352c is supported on the valve body 352a of the needle valve 352. The elongated rod 352b of the needle valve 352 has a smaller diameter than the seed lumen so that when the rod is inserted into the seed lumen, it will block the passage of the therapeutic seed and only allow fluid to pass.

The needle valve 352 is actuated by a slider 366 that is seated in an elongated slot 368 (see FIG. 31) in the assembly 356, which is operated by the valve actuator switch 320. Referring now to FIG. 40B, slider 366 includes two generally L-shaped legs 370a and 370B attached at its proximal end, the free ends of which form a ramp that cooperates with a transverse head 352C (best shown in FIG. 32C) of needle 352 to move the needle out of the seed lumen as slider 366 is moved from the proximal end to the distal end. Legs 370a and 370b straddle rails 372 formed on assembly 356 (see fig. 32A). A pivoting latch 374 (see fig. 32A, 40C) is biased by a spring steel (24GA) leaf spring 376 to push the transverse head 352C of the needle 352 down the incline formed by the legs 370A and 370b as the slider 366 moves distally toward proximally, thereby causing the needle 362 to block the seed chamber. Leaf spring 376 is preferably supported by a block 378 secured to assembly 356 by two screws 380 disposed in tapered bores in assembly 356. It is contemplated that the slide 366, rotary lock 374 and block 378 are each made of aluminum.

According to the present invention, an interlock mechanism is provided between the release switch 358 and the slider 366. Specifically, the distal end of the slider 366 is provided with an extension shaft 382 that prevents the slider 366 from moving proximally toward the distal end to withdraw the needle valve unless the shaft 382 is aligned with the through-hole 358c in the switch body 358a of the release switch 358 (similarly, the shaft 384 extends from the proximal end of the slider 366 to prevent the slider 366 from moving distally toward the proximal end). However, when the arcuate cutout ramp 358b on the catheter attachment and release switches 358 are engaged with the recessed portion 362 of the catheter connector 364, the through-hole 358c is only aligned with the shaft 382. Thus, needle valve 352 cannot be withdrawn by slide 366 unless the catheter is connected to a delivery device such that through-hole 358c is aligned with shaft 382. In addition, the release switch 359 cannot be depressed when the shaft 382 is passed through the hole 358c, thereby preventing the release switch 358 from being released from the recessed portion 362 on the catheter connector. Thus, if the needle valve is withdrawn, the catheter cannot be released by the delivery device. As an additional safety measure, the valve actuator switch 320 is configured to at least partially cover the release button 318 (best shown in FIG. 32C) on the release switch 358 when the needle 352 is withdrawn, which prevents the release button 318 from being depressed.

According to another aspect of the invention, the catheter connector 364 is provided with a detent that interlocks with the delivery device 300 and must be manually actuated to disengage the catheter connector 364 from the delivery device simultaneously with the depression of the release button 318. This increases safety because the operator is required to work in concert with both hands to remove the catheter from the delivery device.

Referring now to fig. 41A-41C, it can be seen that the catheter connector 364 includes an intermediate plug portion 386 having a through bore 388 for receiving a connector insert 390 (fig. 41E and 41D, both of which are described below) and a sleeve member 392 that surrounds a distal portion 394a of the connector that remains outside of the delivery device when the connector is connected to the delivery device. The proximal end 394b of the connector is disposed in the delivery device.

The intermediate plug portion 386 of the connector 364 is provided with two integrally connected diametrically opposed arms 396 which are connected at the distal end of the intermediate plug portion 386 and extend axially along but are spaced from the intermediate plug portion. The proximal end of the cantilever arms 396 is provided with a transverse detent 398 which snaps into contact with a shoulder 400 (see fig. 32C) on the distal end of the delivery device when the connector is inserted into the delivery device, thereby holding the connector in place. To disengage the connector from the delivery device, the cantilever arms 396 must be pushed radially inward to disengage the catch tabs 398 from the shoulder 400. At the same time, the release button 318 must be depressed to release the release switch from the connector.

To prevent foreign objects from reaching the delivery device outlet through the gap between the cantilever arms 396 and the intermediate prong 386, the sleeve member 392 is fitted over the distal end 394a of the connector when the connector is connected to the delivery device, with the proximal end of the sleeve member 392 abutting the distal end of the delivery device. The sleeve member 392 is sufficiently flexible to allow manipulation of the cantilever arms 396 to permit removal of the catheter.

Connector insert 390 (see fig. 41E and 41D) has an internal through-bore cavity 402 that is double stepped along the distal end of insert 390. Insert 390 is molded into the proximal-most end of catheter body 404 (only the seed and fluid return passages) and shield 406. The proximal ends of the shield tube 406 and catheter body 404 are disposed in the stepped portion of the insert 390, while the third channel 408 is in fluid communication with a seed lumen connection of the catheter with a chamfered proximal end 410. A second bifurcation 412 is provided in the insert so that the fluid passageway lumen is angularly spaced from the seed lumen and communicates with the outer periphery of the catheter connector 364 through an arcuate passageway 414 which communicates from the outlet of the insert to an opening 416 in the sidewall of the catheter connector 364. The catheter connector 364 is slid through the catheter insert subassembly 418 (see FIG. 42A) to seat the insert 390 in the catheter connector 364. The proximal end of the insert 390 is aligned with the proximal end of the catheter connector 364 and the UV-cured adhesive is injected through the connector sidewall into the other opening 420. The adhesive flows through the lumen into the void area in the catheter connector and permanently secures the insert 390 in the catheter connector 364. Alternatively, the conduit connector 364 may be molded onto the outer perimeter of the insert 390 after the insert has been molded into the dual lumen conduit portion.

The chamfered portion 410 of the catheter connector 364 mates with a mating protrusion 422 (best seen in FIG. 32C) at the distal end of the assembly 356. This engagement provides the best alignment of the catheter connector 364 between the connector lumen and the fluid lumen in the assembly 356, thereby minimizing fluid leakage at the catheter connector/assembly interface.

Referring now to fig. 42A and 42D, a catheter 424 of the present invention is shown similar to the catheter of the related, co-pending patent application previously described. The catheter 424 has a proximal end 426, a distal end 428, and an elongate portion 430 connected thereto. As best seen in FIG. 42D, the catheter 424 is provided with a seed lumen 432, a fluid return lumen 434, and a guidewire lumen 436. The seed lumen 432 and fluid return lumen 434 are contiguous from the proximal end 394b of the catheter connector 364 to the distal end 428 of the catheter 424, where it communicates through an intraluminal connector 438 (see fig. 42C) that is disposed in the seed lumen 432. The intraluminal connector 438, which is preferably made of stainless steel, also reinforces the distal end 428 of the catheter 424 to prevent the treatment unit from escaping from the distal end of the catheter.

The seed lumen 432 and the guidewire lumen 436 of the catheter 424 are both substantially circular in cross-section, as shown in fig. 42D. However, the fluid return lumen 434 is elliptical in cross-section to increase the area through which fluid can flow without regard to the outer diameter of the catheter 424. Increasing the area reduces the pressure required to deliver, hold and retrieve the treatment unit. It also reduces the time required to deliver a treatment unit from the delivery device 300 to the distal end 428 of the catheter 424 and vice versa. However, the fluid return lumen 434 can be selected to be any size and shape so that a limited amount of fluid can be used to desirably deliver the treatment unit.

For uniformity of dose, it can be determined that the treatment unit needs to be placed at or near the center of the lumen wall. In this case, it is desirable to position the seed lumen 432 as close as possible to the center of the catheter 424 to prevent the seed lumen 432 and the radioactive unit from being too close to one side of the lumen wall.

The conduit 424 is preferably extruded in one pass from 100% low density polyethylene material which is very flexible and smooth. These features allow the catheter 424 to be inserted over a guidewire into the luminal area of the body without damaging the lumen wall, if 100% polyethylene is too soft or prone to buckling, then a hybrid polyethylene is used that consists of a proportion of high density and low density polyethylene. In order to maintain the flexibility of the catheter, the hybrid polyethylene must contain a high percentage of low density polyethylene.

Referring now to fig. 42A-42C, a atraumatic tip 440 having a small taper (preferably equal to or less than 11 °) and a small distal tip radius, the tip 440 merges (possibly with high frequency energy) at the distal end 428 of the catheter 424. The fusion process melts the seed lumen 432 and the fluid return lumen 434 causing them to close. The top portion 440 is formed of polyethylene, preferably ethylene vinyl acetate. The guidewire lumen 436 passes through the tip 440 and is aligned for connection to a high density/low density polyethylene sleeve 442 (see fig. 42C). The sleeve 442 is made of a material having a higher durometer than the tip 440 so that the catheter is delivered over the guidewire without tearing the tip 440.

A radiopaque marker band 444 made of a platinum (90%) -iridium (10%) alloy is provided at the distal end 428 of the catheter 424 to facilitate proper positioning of both the catheter 424 and the treatment unit. The identification band 444 is flush mounted around the circumference of the catheter 424. Alternatively, the radiopaque marker band 444 may be comprised of radiopaque ink or fine radiopaque particles printed or sprayed on the outer circumference of the catheter 424. The catheter proximal portion 426 may also be provided with a depth indicator (not shown) to indicate when the catheter is near the end of the guidewire so that the fluoroscope can be turned on just prior to delivery of the radiation treatment.

The proximal end 426 of the catheter is also provided with a bifurcated port 446 where the guidewire lumen 436 branches from the catheter portion 430 to connect to a guidewire extension tube 448. The guidewire extension tube 448 may include a standard luer fitting 450, which may or may not include a valve for preventing blood from escaping the proximal end of the guidewire lumen 436. The lead extension tube 448 and the furcation mouth 446 may be made of polyethylene or a mixture of polyethylene and ethylene vinyl acetate. The seed lumen 432 and the fluid return lumen 434 remain in abutment throughout the bifurcated mouth 446. A Strain relief tube (Strain relief tube) 452 is secured to the bifurcated mouth 446, extends a short distance outwardly therefrom, and is then matingly disposed at the proximal end of the catheter portion 430. The strain relief tube 452 increases stiffness proximate the furcation mouth 446 to protect the conduit 424 from kinking or other damage. In addition, a shielding tube 406 is fitted over the end of the catheter near the bifurcated mouth 446 to increase the shielding of the radiation therapy unit as it is delivered into and out of the catheter 424.

At a particular point in the radiation treatment process, it may be necessary or desirable to determine the position of the treatment unit and the identifier seed relative to the quartz housing 308 in the delivery device 300. For example, assuming a radioactive source array comprising 12 stainless steel-packaged radioactive treatment units with an inert gold seed at each end of the source array, a user may need to verify that all of the 12 treatment units and 2 seed are in the quartz housing 308 before delivering the treatment units to the distal end of the catheter 424, and that all of the treatment units and seed are in the quartz housing 308 before closing the needle valve 352 to disengage the catheter 424 from the delivery device 300.

To determine whether all of the treatment units are in the quartz housing 308, an electronic detection system (shown schematically in FIG. 45) is provided in the delivery device 300 that determines the presence or absence of the distal gold marker seed at a single location within the lumen 308a of the quartz housing 308. The system detects the gold marker seeds by colorimetric analysis by irradiating the gold marker seeds with different wavelengths to a small area range where the gold marker seeds are located in the quartz shell 308 and then measuring the reflectivity. Depending on the ratio of wavelength/reflection of the different lights, the system determines whether a gold object (gold marker seed) or a non-gold object (stainless steel seed, background, or lumen 308a in quartz housing 308 filled with saline) occupies the illuminated area. If a gold seed is detected within this small area, the user has reason to believe that it is the remote seed and that all treatment units close to this remote seed are in the quartz housing 308. To improve the certainty that all of the seeds are in the quartz housing 308, an electronic sensor may be enhanced to determine whether both of the identification seeds are properly positioned in the quartz housing and/or to effectively determine whether some or all of the stainless steel treatment units are properly positioned in the quartz housing. However, this requires more space in the housing of the transport apparatus 300 for the added electronics and optics.

In addition to detecting the presence or absence of a gold marker seed at a particular location along the quartz lumen 308a, the electronics wait for the pressing of the power button 312 in a low power state. After the power button 312 is pressed, the two indicator Light Emitting Diodes (LEDs) 310a and 310b blink for several seconds to indicate that the Light Emitting Diodes (LEDs) 310a and 310b and the battery 454 are functioning properly, and then indicate whether a gold-labeled seed is detected based on the illumination of one of the two indicator Light Emitting Diodes (LEDs) 310a,310 b. Fig. 29B, fig. 31, fig. 32B and fig. 37 illustrate a single C-cell lithium battery used to power an electronic system. The electronic system is preferably charged by two thin batteries used in series to produce +6V power from a single battery pack. The output can also be converted to produce a-6V power. Finally, after one minute has elapsed, the electronic system automatically returns to a low power state to conserve battery power, or if the button is pressed again during this one minute period, the system restarts the one minute timing cycle.

Referring to the logic diagram of fig. 45, the battery is designated 456. The power supply is controlled by a Sleep circuit (Sleep circuit). Applying power causes the sleep circuit to shut down, which in turn shuts off power, so that only enough power is needed to keep the system running. The On-Switch 458 is a normally open push button Switch 312. When the switch 458 is closed by pressing the button 312 from the periphery of the conveyor 300, the sleep circuit wakes up, turning on the power supplies 460,462, one producing +6V and the other producing-6V. The generated power first activates the internal clock 464, which is set to about one minute. The internal clock is an analog circuit, but may be a digital circuit using a calculator in order to obtain higher accuracy and longer time. At the end of one minute, the power supplies 460,462 are turned off and the sleep circuit returns to sleep until the next time the switch 458 is closed. If the button 312 is pressed during a one minute sizing cycle, the timing cycle will be reset to enable power for a longer period than one minute in total. The internal clock may be designed to accommodate other lengths of time. Each time the one minute clock 464 is started, a 4 second test period also begins and a 4 hz oscillator 468 is started, which generates a 4 hz square wave. A square wave and a 4 second clock are applied to indicator LED driver 470 to cause both indicator LEDs 310a,310b to flash simultaneously at 4 hertz for 4 seconds (one green and the other amber). This action informs the user that battery 454 and indicator KED310a,310b are in the process of operating. After a 4 second test period, the system enters its normal test state.

The detection state utilizes the optical characteristics of stainless steel (material encapsulating the radioisotope) and gold (marker seed material or marker seed coating material) and the effect of red and blue light on each of the stainless steel and gold seeds. The optics of the system include a blue light emitting diode 472 using gallium nitride (GaN), a red light emitting diode 474 using gallium phosphide, a photosensor 476 containing a photodiode and integrating amplifier (Integrated amplifier), a GRIN (Graded Index) lens 478, and a second photosensor 480, all of which are housed in the assembly 356 housing the quartz sleeve 308. In fig. 32A, the first photosensor 476 is oriented perpendicular to the quartz sleeve 308, and the blue led 472 and the red led 474 on either side of the first photosensor 476 are also oriented at an angle to the first photosensor 476. Other orientations of the light emitting diodes relative to the light sensing device, and the light sensing device relative to the quartz housing, may be used to improve the accuracy of the electronic detection circuitry. A channel 482 in the assembly 356 directs light exiting the light emitting diode 472,474 to a target location on the quartz sleeve 308 and also directs reflected light back onto the first photosensor 476. A GRIN lens 478 is positioned between the quartz sleeve 308 and the first light sensing device 476 and focuses light at a location on the quartz lumen 308a where the distal gold identifies when all treatment units are disposed in the quartz lumen 308 a. The GRIN lens 478 now concentrates the light, which is then directed to the surface of the photodiode.

The blue and red leds 472,474 used in this system supply blue and red light in limited wavelength bands with peak values of 450 nm and 700 nm, respectively. At 450 nanometers, stainless steel (and a blue-lit or non-blue-lit background) has a reflectance of greater than 90%, while gold has a reflectance of about 35%; at 700 nanometers, both stainless steel and gold have a reflectance greater than 90%. This means that stainless steel reflects blue and red light equally well, while gold reflects red light well, but reflects blue light poorly (gold actually absorbs blue light). Thus, the measurement of the blue/red ratio of the reflected light in the field of view of the light-sensitive device enables unambiguous discrimination between a gold-colored object, in this case a gold marker, and other objects.

A clock oscillator 484 oscillating at a frequency of 3.22 khz alternately (180 deg. out of phase) flashes blue 472 and red 474 leds. Clock oscillator 484 is operated by a bi-stable multivibrator (Flip-flop)486 in which the frequency is divided to produce two signals, each having a frequency of 1.61 khz. Therefore, when the blue light emitting diode 472 and the red light emitting diode 474 alternately blink and blink, the blinking time and the extinguishing time thereof are equal. The flashing blue and red light travels from the leds 472 and 474 through the channel 482 in the assembly and through the quartz sleeve 308 to the target site where the distal gold marker should be when all the seeds are in the quartz lumen 308 a. If a stainless steel seed is occupying the target site, then both blue and red light are reflected equally well (greater than 90%). If only fluid or gas is flooding the target site, the background can also reflect both blue and red light similar to stainless steel, as long as the background is not colored. If a gold marker seed is in the target site, red light is reflected and blue light is absorbed. A first photosensor 476, consisting of a photodiode and an integrated amplifier, is optically coupled to the target site in quartz sleeve 308 through a gain lens 478 so that photosensor 476 measures the amount of each of the blue and red light reflected. The blue/red ratio of the reflected light, as determined, can be used to determine whether a gold mark is present.

The window 306 along the top 302a of the conveyor 300 allows ambient light to also be emitted from objects in the light-sensing device 476. The photosensor 476 is most likely to detect ambient light in addition to red and blue light. The ambient light signal may adversely affect the output of the light sensitive device 476. The light sensing device 476 must operate even if light enters through a transparent window. Therefore, the signal generated by the ambient light source must be removed from the system. This can be achieved by using a high pass filter 493 followed by a synchronous detector 494 and followed by a low pass filter 496. The synchronous detector 494 is a line synchronized with the blue-red led pulses. The sync filter 494 filters out all AC signals except the signal generated by the blue-red led 472,474. The low pass filter 496 converts the AC (alternating current) output from the photosensor 476 to a DC (direct current) voltage because the system depends on the difference between the red and blue signals. A Blanking line (Blanking Circuit) is also provided to trip the low pass filter for a short period after each clock transition to improve the accuracy of the low pass filtered signal. The amplitude of these signals corresponds to how much light is reflected off the target site, and the DC voltage is proportional to the blue/red ratio of the reflected light. This line is regulated such that the DC voltage output is zero in the presence of gold at the target site. In the presence of other objects at the target site, the output is a non-zero voltage.

The system is designed to produce a zero voltage in the case of gold detection (and a non-zero voltage in the case of stainless steel detection or background) because the zero signal is not affected by any gain encountered along the signal path (zero times any value is always zero); thus, there is nothing that can go outside the Tolerance window (Tolerance window) established according to the reference voltage (zero) to be detected. Since the null signal is substantially unaffected by variations in the system, such as mechanical tolerances and temperature variations, it is much more reliable than a non-zero voltage. Gold should produce a zero signal because this is a signal state that must be distinguished from any other signal. When the gold marker occupies the target site, the only adjustment required to bring the output voltage to zero is to adjust the intensity at which the blue led 472 emits light. If this adjustment is not made, the stainless steel will produce a zero signal because the stainless steel will reflect blue and red light equally and produce a signal that approaches its same amplitude when the intensity of the light emitted by the blue-red led 472,474 is made equal. Two electrical signals of the same amplitude produce a zero voltage. In contrast, because gold reflects red light and absorbs blue light when the blue-red led 472,474 emits light at the same intensity, the photosensor 476 outputs signals of different amplitudes (high signal is red and low signal is blue), which are converted to a non-zero DC voltage. To produce a zero signal in the presence of gold, rather than stainless steel, must produce the same amount of reflection for both blue and red light. This may be accomplished by increasing the excitation of blue led 472 more than red led 474 so that the intensity of the blue led 472 is greater than the intensity of red led 474. The gold now reflects blue and red light equally, which results in no AC signal being generated from the light sensing device 476, thereby forming a zero signal. On the other hand, the stainless steel reflection is brighter due to the blue light because the enhancement is given to the blue led driver 490. Therefore, the blue signal is larger than the red signal and the resulting square wave forms a non-zero DC voltage. To ensure that the stainless steel treatment unit and the background always produce a non-zero output voltage, they should not be colored or bluish in order to reflect blue light and absorb red light, which is the opposite of what gold does.

When the DC signal is at a zero voltage value, the system indicates that the presence of gold has been detected. In actual operation, however, the DC signal is almost always not at exactly zero voltage due to some variation within the system. Therefore, a window detector 498 with an upper reference voltage and a lower reference voltage establishes a range centered at zero. The window detector 498 receives the DC signal and then determines whether the signal falls within a set range (e.g., -11 to +11 millivolts). If the signal falls within this range, the window detector will determine that the signal corresponds to the presence of gold. The width of the window can be varied to vary the tolerance of the system according to the error (small widths are suitable for tight tolerances). After the signal passes through the window detector, the decoded signal enters two drivers for the indicator leds 310a,310 b. If the decode signal indicates the presence of gold, a green LED310a positioned along the top 302a of the transfer device 300 illuminates to indicate to the user that all treatment units are in the quartz housing 308; if the decode signal indicates that no gold is present, amber LED310 b positioned along the top 302a of the delivery device 300 will illuminate, indicating to the user that not all of the treatment units are in the quartz housing 308.

The blue and red leds 472,474 are temperature sensitive, with their outputs affected by other factors, such as Aging (Aging), current excitation levels, and possibly ionizing emissions. In particular, the output of the red light emitting diode 474 significantly decreases with increasing temperature and increases significantly with decreasing temperature. These temperature-induced changes in the output of the red led 474 interfere with the blue/red ratio of the reflected light, and may hinder the ability of the system to detect the presence of gold. To stabilize the output of the red led 474, a brightness control loop is provided to adjust the output to compensate for any temperature factors so that the output of the red led 474 remains constant. However, the blue LED 472 is fairly stable to temperature variations over the normal operating temperature range (+ 10C- + 35C). There is no need to provide a brightness control loop for blue led 472. A red led brightness control loop is added to the second photosensor 480. The second photosensor 480 compensates for temperature-induced changes in the output of the red led 474 by "Staring" only at the apex of the red led 474 and determining how much light it produces. To better measure the output, the second photosensor 480 is positioned at a 90 ° angle to the longitudinal axis of the red led 474. The method of detecting the output signal of the red led 474 is the same as the method of detecting the blue/red reflected signal, i.e., by the synchronous detector 500a and the high pass filter 502c and low pass filter 504 a. The output signal then passes through an inverting DC amplifier 506a, which adjusts the control loop gain. The signal provides a negative gain to the reference signal 508c (RED/REF) that sets the RED led drive range. The adjusted signal into the red led driver 492 attempts to keep the red led 474 output stable, although the actual amount of light may vary for any given current. This is a very simple loop; other structures known to those skilled in the art may be used in place of this circuit. A control loop may also be added to the blue led to improve the stability of its output.

A wiring diagram corresponding to the logic block diagram of fig. 45 is shown in fig. 45A-45C. FIG. 46B shows a one minute timer, a +5 power supply and a-5 power supply. FIG. 46C-1, FIG. 46C-2, and FIG. 46C-3 show three circuits: a +2.5 reference voltage; a program for blue signals; and a program for a red signal. FIGS. 46A-1 and 46A-2 show two LED current drivers, a blanking line, a 3 kHz oscillator, a 4 kHz clock, a Window detector and Window range (Window threshold). These diagrams illustrate the components of an electronic device and how they relate to each other in an electronic device system. A specific layout is shown. Other components or circuit designs that produce the same output may be used. The traces are printed on plates 510a and 512a (see fig. 31) which are mounted on the carrier 304 of the conveyor 300.

In support of the electron source detection system, a window 306 above the quartz housing allows the user of the delivery device 300 to visually detect whether all of the treatment units are within the quartz sleeve 308 by either detecting the presence of a marker seed at either end of the treatment units or counting the number of treatment units and marker seeds within the quartz sleeve 308. To facilitate visual inspection by the user, a magnifying glass 514a (see FIG. 32A) is secured to the top of half shell 302A and is positioned directly above quartz lumen 308 a. Magnifier 514a is also positioned above indicator leds 310a and 310b so that the diodes are also magnified.

Referring now to fig. 47-51C, an improved delivery device 500 for a catheter delivery system for radiation therapy according to the present invention is shown. Similar to the delivery device 300, the delivery device 500 has an outer structure that is ergonomically designed for the user's manipulation and inner components including a pressure indicator, pressure relief valve, flow control valve and passageway, quartz housing, a catheter connector/needle valve interlock system, and a treatment unit electronic detection system. These and other component modifications, as well as additional features of the delivery device 500 for added safety and user responsiveness, are described in detail below.

As shown in the exploded view of fig. 50, the outer structure of the transfer device 500 is comprised of an upper portion 502a and a lower portion 502b, each of which forms a half shell. The two half-shells 502a,502b are brought together to enclose a support 504 therein, on which the components of the transfer device 500 are mounted. Openings in the upper housing half 502a allow a user to access a power button 506 for operating an electronic detection system and indicator lights 508a,508b and a fluid control switch 510 for operating a fluid control valve 512 (see fig. 47). The upper housing half 502a is also provided with a pressure indicator window 514, and a magnifying window 516 for viewing the indicator lights 508a and 508b, a quartz sleeve 518 for storing treatment units and seed markers, and a distal passage 523 leading from the quartz sleeve 518 to a distal opening 524 of the delivery device 500. The two halves 508a and 508b together form openings along the sides of the transfer device 500 through which a fluid access port 526, a spool valve actuator switch 528, and either end of a locking mechanism 586 for a catheter connector are accessible. The two half shells 508a and 508b together also define an opening 524 (see FIG. 49) at the distal end of the delivery device 500 for receiving a catheter connector, and an opening at the proximal end of the delivery device 500 through which a fluid discharge port 530 is accessible, which preferably does not extend too far beyond the outer wall of the delivery device 500, if extended. The compartment for storing the fluid collection bag (mentioned in the description of the transfer device 300) may be eliminated to provide space for internal components in the transfer device 500. Alternatively, a clamp may be added to the bottom of the transfer device 500 to secure the fluid collection bag (not shown). Polyurethane is an example of a material that may be used to form the two half shells 508a and 508 b.

The delivery device 500 has a fluid inlet 526 to which a source of pressurized fluid (liquid or gas), such as a fluid-filled syringe or an automated fluid pump, is connected for hydraulically or pneumatically delivering and retrieving the treatment unit. As shown in fig. 51A, the fluid inlet 526 has a luer connection. The two offset hips 532a and 532b are similar to the support arms 326a and 326b mentioned in the description of the transfer device 300 and extend from the housing portions 502a and 502b to support the syringe 534a in a position oriented along the side of the transfer device and positioned at a predetermined angle to the longitudinal axis of the transfer device to facilitate manipulation of the syringe plunger 534b and proper alignment of the distal end of the syringe 534a with the fluid inlet port 526. As shown in fig. 48, the syringe 534a is angled approximately 7 ° outward and approximately 25 ° upward relative to the longitudinal plane of the transfer device 500. The configuration of the support arms 532a and 532b (see fig. 47 and 49) is such that the support arm 532a extending from the upper housing portion is proximate to the support arm 532b extending from the lower housing half, thus providing a clear line of location between the proximal end of the delivery device 500 and the fluid inlet port 526 to allow for quick and easy attachment of the syringe 534 a.

Referring now to fig. 50-51B and 52, the support of the transfer device 500 also supports a pressure indicator 536 and a pressure relief valve 538, which operate independently of one another. The pressure indicator 536 helps the user determine the appropriate pressure required to deliver and retrieve the treatment unit from the distal end of the catheter and to maintain the treatment unit at the distal end of the catheter during treatment. The pressure relief valve 538 prevents over-pressurization of the system, which could damage the conduit and/or the transfer device 500.

Pressure indicator 536 comprises a hollow cylindrical body member 540 having an inlet port 542 at one end thereof in fluid communication with a fluid source and an end plug 544 at the other end thereof. Cylindrical member 540 has disposed therein a plunger 546 and a compression spring 548 positioned between plunger 546 and end plug 544. The piston 546 may be an annular seal, such as the one described above for the delivery device 300, a rubber plunger, which may be obtained from a syringe, or a piston made of a relatively hard material and provided with an O-ring groove in which the O-ring is seated, such that the O-ring and O-ring groove form a seal against the inner wall of the cylinder. Spring 548 is preferably made of stainless steel, such as the part number C0300-032-18, available from Middy Westexpress Company. The compression spring 548 employed must have a spring rate (i.e., deflection per unit of force) that causes the plunger 546 to be pressed against the pressure indicator window 514 at a specific location so that the system has its operating pressure (0-100 ± 15 psi). The pressure within the transfer device 500 created by the fluid source pushes on the piston 546 in the cylindrical member 540 such that the piston compresses the spring 548 and forces air at the other end of the piston out of the exhaust port in the end plug 544. The seal formed between the piston 546 and the circumference of the inner wall of the cylindrical member prevents fluid from bypassing the piston 546. As shown in FIG. 47, the piston 546 is fitted with a piston ring 550 that is clearly visible through the pressure indicator window 514. The piston ring 550 not only acts as a pressure indicator, but also adds some stiffness to the middle of the piston 546. Additionally, a background material may be disposed along the bottom of the cylindrical member 540 to block the view of other components that may interfere with the visibility of the piston 546 and piston rings 550. However, other standard pressure gauges may be used in place of the spring loaded piston and cylinder member arrangement described above.

Words and/or indicia are provided on the outer structure of the delivery device 500 proximate the pressure indicator window 514 to indicate where the piston ring 550 should be positioned in the pressure indicator window 514 to provide the proper pressure to deliver and retrieve the therapy unit from the catheter and where the piston ring 550 should be positioned to provide the proper pressure to maintain the therapy unit at the distal end of the catheter during therapy. The pressure used to hold the treatment unit at the distal end of the catheter is much less than the pressure required to rapidly deliver and retrieve the treatment unit. Both pressure indicator 536 and pressure relief valve 538 are held in place by an L-shaped block member 556 mounted on support 504.

The pressure relief valve 538 is a standard valve having a starting pressure of 100 + -15 psi. Such a valve may be, for example, one manufactured by Lee Company of vestbreok city, Westbrook, connecticut, having part number PCRM 00000015. The pressure relief valve 538 includes a pin, a ball, a spring and a spring retainer, which is press fit into a pressure relief valve housing 558. A fluid connector 559 is provided at each end of the pressure relief valve housing 558. System pressures in excess of 100 ± 15 psi are sufficient to cause the spring-loaded ball to open, allowing fluid to flow through the valve 538 and out of the transfer device 500 through the fluid outlet 530 into an external fluid reservoir (not shown). If the pressure does not exceed the value described above, the spring will urge the ball against its seat, thereby preventing fluid flow through the valve 538 and allowing fluid to continue to flow safely through the system.

The fluid control valve 512 has the same shape and function as the fluid control valve 330 shown in fig. 31. The fluid control valve 512 of the present shuttle 500 directs the flow of fluid through the system by toggling the flow control switch 510 between the locked delivery, return and neutral positions. The control valve 512 may include four ports 562 and may withstand the highest operating pressures of the system (i.e., at least 100 pounds per square inch) such as those manufactured by Hamilton Company of Reno, Nevada, part number 0162336(HV4-4, w/.040 ports).

As described above, the internal components of the transfer device 500 are separately manufactured and then mounted on a support on which they are connected in fluid communication by tubing (not shown) and Barbed connectors (Barbed connectors), such as connector 542 shown in FIG. 52. FIG. 53 is a schematic view of a fluid flow control system illustrating the fluid flow of the system visually.

Referring now to fig. 48 and 50-51C, the transfer device 500 further includes a separate assembly 564 mounted on the support 504, in which the quartz sleeve 518 is disposed; a needle valve mechanism 576; and an optical portion of the seed verification system. As a modification to the assembly 564 of the previously described transfer device 300, the present assembly 564 is provided with an engaging projection 566 that is machined below the surface of the assembly 564 so as to be recessed within the recess 568. This simplified design reduces the number of components so that the O-ring groove 570 can be cut directly into the wall of the component recess 568 surrounding the engagement tab 566.

The assembly 564 may comprise a spring-loaded assembly (not shown) for holding the quartz sleeve 518 in its correct position (aligned with the optics for proper seed detection) even if the transfer device 500 is disengaged. A lumen 572 is provided extending along the length of the quartz sleeve 518 for storing treatment units and marker seeds that have not been used for radiation therapy. The quartz sleeve 518 shields the user from beta particles emitted from the treatment units stored in the sleeve so that the user can safely operate the delivery device 500. The distal end of quartz lumen 572 is preferably provided with a chamfer to prevent seed lay-up during seed delivery. As previously described, the entire length of the quartz sleeve 518 can be viewed through an opening in the assembly that is aligned with the viewing window 516. To more clearly view the treatment elements and marker seeds in the quartz sleeve 518, a colored material (preferably white) may be adhesively affixed or otherwise disposed on the bottom of the quartz sleeve.

The needle valve mechanism includes a needle valve 578a, a cylindrical pin head 578b, a slider 580, a pivoting lock 582, a leaf spring 584a, and a leaf spring 584b, all of which work together to place the needle valve 578a in either an extended position (closed) or a retracted position (open) relative to the lumen 523 at the distal end of the quartz sleeve 518 to respectively prevent or allow passage of the treatment unit. The components and function of the needle valve mechanism 576 are the same as the needle valve mechanism 352 described above in the conveyor 300. The needle valve mechanism 576 of the present invention provides more safety against the needle valve 578a reaching and thereby damaging the treatment unit. If an attempt is made to close the needle 579a while the treatment element is in the passage of the needle 578a, the pivoting lock 582 is oriented so that it does not move out of the passage of the moving slide, thereby preventing further forward movement of the slide, which would prevent downward movement of the needle into contact with the treatment element. Additionally, the needle valve mechanism 576 may be configured such that the needle valve 578a may be telescoped into the distal end of the quartz lumen 572 through a radial passage extending from the top of the quartz sleeve 518 and intersecting the quartz lumen 572.

Instead of the release trigger/release switch mechanism 350 (see fig. 38), the transfer device 500 is provided with a latching mechanism 586 (see fig. 48, 51A, and 54A-56C) for mounting, latching, and properly positioning the catheter connectors in the transfer device. The assembly of locking mechanism 586 includes a lock body 590, a lock locker 592, a lock button 594, and two ball and spring plungers 596, all of which are located between the assembly 564 and the end body 598 of the transfer device 500. 54A-54B and 56B, locking element 590 is substantially rectangular in shape, having an elongated opening as viewed from its distal end face and a raised portion with a U-shaped recess as viewed from its proximal end face. The U-shaped recess is adjacent the elongated opening, has a portion extending along the length of the opening, and is accessible through the opening. Since the U-shaped recess is smaller than the elongated opening, some of the raised U-shaped portion surrounding the recess overlaps a portion of the elongated opening. Lock body 590 is preferably formed of an opaque material, such as delrin, to provide lubricity between it and the polycarbonate member (i.e., assembly portion 564 and end body 598) to provide sliding contact therebetween due to the lubricity. A locker 592 (fig. 55 and 56B-56C) fits into a similarly shaped concave portion disposed along the proximal face of the locking body 590 such that the small end 606 of the locker 592 extends into the elongated opening (see fig. 56B). Lock button 594 contains a compression spring 608 therein and slides over upper ends 610,612 of lock plunger 592 and lock body 590 such that lock plunger 592 and compression spring 608 contact one another and lock button 594 is secured to lock body 590. A ball and spring plunger 596 (see fig. 50) extends from the shallow bore in the end body 598 such that each of the two balls seats in one of the recesses 614 provided along the proximal face of the locking element body 590 between the elongated opening and the extension with the through bore.

When the catheter connector 588 is inserted into the delivery device 500, the distal end of the connector 588 passes through the unobstructed half of the elongated opening of the lock body 590, seating itself on the engagement ledge 566 extending from the assembly 664 (see FIGS. 51A-51B). To lock the connector 588 in the delivery device 500, the lock member button 594 is pressed inward to facilitate engagement of the recessed portion of the connector 588 with the U-shaped portion which overlaps the elongated opening of the lock member 590. The two ball and spring plungers 596 ramp onto the apex 616 of the locking body proximal face adjacent the recess 614 as the locking body 590 moves from the unlocked position to the locked position. This ramped movement causes spring loaded plunger 596 to compress lock body 590 and mating connector 588 and drive them toward engagement tab 566 at the distal end of assembly 664; this ensures that the chamfered portion 618 of the connector insert 632 is fully seated against the boss 588 and is fully centered with its opening. As an indication that the connector 588 is fully connected, the free end 620 of the locking element 590 (opposite the end connected to the locking element button 594) may pop out from the side of the delivery device 500 (see fig. 47, 48 and 51A). If the identification band or other indicia provided on the free end 620 is fully visible, the user can be assured that the connector 588 is now locked in the delivery device 500. To release the connector 588 from the delivery device, the lock body 590 is pressed inward to disengage the U-shaped portion from the recess of the connector 588.

To provide a relatively safe delivery device, an interlocking mechanism is provided between the locking body 590 and the slider 580, as shown in fig. 48 and 51A. The slider 580 slides toward the distal end of the delivery device 500, retracting the needle 578a, thereby allowing the treatment unit to be delivered out of the delivery device 500. To enable this movement, the shaft 581 and locking element button 594 extending from the distal end of the slider 580, the locking element 592 and the aperture in the locking element body 590 all must be centered. When the latching mechanism 586 is in the unlatched position, the extension axis 581 is not aligned with the throughbore regardless of the insertion of the connector 588 into the transfer device 500, and in addition, the actuator switch 528 is blocked by the snap-up latch button 594. When locking mechanism 586 is in the locked position and the connector is not locked in transfer device 500, the through-holes in lock button 592 are not perfectly aligned with the through-holes in lock button 594, and the movement of slider 580 is limited by lock button 592. However, when the connector 588 is inserted into the delivery device 500 and the lock body 590 is slid toward the connector 588 for mating, the small end 606 of the locker 592 is impacted against the connector 588 above the connector recess 589 and pushed toward the lock button 594 against the spring 608 so that the locker through-hole is now centered with both the lock body through-hole and the lock button through-hole. Thus, when the connector 588 is inserted into the transfer device 500 and fully engaged with the locking mechanism 586, the needle 578a can only be retracted to a gate-on position. In addition, when the requirements are met and the shaft 581 passes through the three holes, as shown in fig. 51A, the lock body 590 cannot slide back to the unlocked position, thereby preventing the lock body 590 from being removed from the recess 589 on the connector 588. As an additional safety measure and visual cue to the user that the connector 588 cannot be disengaged from the delivery device 500 when the needle 578a is in the retracted position, the actuator switch 528 is configured to at least partially cover the lock button 594, thereby preventing the lock body 590 from being moved into the unlocked position.

Referring now to fig. 57A-58A and 57C, a catheter connector, which is part of the present invention, is provided with a detent 626 that interlocks with an annular shoulder on the end body 598 of the transfer device 500 and must be manually manipulated to remove the catheter connector 588 from the transfer device 500 after the catheter connector 588 is released by the locking mechanism 586. The catheter connector 588 comprises: a medial plug portion 630 having a through lumen 630 and arms 634; a connector insert 632 disposed in the king post portion through lumen 630; a shroud skirt 636, 57A-that fits over the distal portion of the connector 588, which remains outside of the delivery device 500 when the connector 588 is fully connected to the delivery device. The connector insert 632 is identical to the connector insert 390 described above and shown in fig. 41E and 41D. The central post 628 may be the same as described above and shown in FIGS. 4C and 4D, or may be slightly different in that the wall between the two O-rings is formed to deflect inward from both ends to enhance the sealing action of the O-rings. The shroud skirt 636 (see fig. 57A-57B and 58A) is threaded on the portion thereof that fits over the catheter tubing, and after the connector 588, which includes the outriggers 634, is connected to the catheter tubing, the shroud skirt fits over the distal portion of the connector 588. When the connector 500 is fully inserted into the delivery device 500, the hood skirt 636 covers the slotted portion 642, leaving the distal portion outside of the delivery device 500, abutting the distal tip of the delivery device 500, and surrounding the inlet section 524 of the connector into the delivery device 500. These features of the shroud skirt 636 serve to keep the distal end of the connector 588 sterile while preventing foreign objects from entering through the slotted portion 642 of the plunger portion 630 and reaching the entrance section from the connector to the transporter 500. As shown in fig. 57A, the hood skirt 636 preferably has two opposing rectangular sides 645 to engage the depressible sides of the hip extension 634 and indicate to the user where to operate the arm extension 634. The shroud skirt 636 is preferably made of silicone or other material having sufficient flexibility to allow the boom 636 to be manipulated when removing the connector 588 from the delivery device 500. Additionally, the rectangular side 645 may be thinner than the remainder of the housing skirt 636 to facilitate easier manipulation of the boom 634. The arm 634 must be pushed while the connector 588 is removed, which is another safety feature that prevents the connector 588 from being inadvertently removed from the transfer device 500.

As shown in FIG. 58A, a catheter 647 of the present invention is coupled to a delivery device 300,500 via a catheter connector 588 to enable delivery of a therapeutic unit to a selected site in a patient. Referring now to fig. 58A-58C, the catheter 647 and its components (except for the catheter connector just described) are the same as those shown in fig. 42A-42D. However, the distal-most marker band of the present invention is in close proximity to the proximal end of the intraluminal connector 646, and the intraluminal connector 646 at the distal end of the catheter may be made of platinum/iridium to allow visualization under fluoroscopy, and the need for the distal marker band 652 may not be present. Also, the catheter fluid lumens 648 and 650 (and in particular the fluid return lumen 650) are preferably sized such that the delivery inch and retrieval time of the treatment element are each in the range of 3-10 seconds, more preferably 2-6 seconds, while the catheter outer diameter does not exceed 5French, the pressure does not exceed 100 pounds per square inch, and less than 20cc of fluid is used to deliver, hold and retrieve the treatment element. Treatment unit 658 is preferably a radioactive source, as disclosed in patent application serial No. 08/628,231, filed on 4/1996, the disclosure of which is incorporated herein by reference. The treatment unit 658 includes 12 radioactive columns 660 in a string and two marker seeds 659a,659b, one for each end of the radioactive group. The identifier seeds 659a,659b are used to properly position the treatment unit 658 at the treatment site and are preferably gold or gold-plated, since gold is shown under a fluoroscope, which can be used to detect radioactive radiation. To reduce the time for the radioactive source array to be delivered to and retrieved from the distal end of the catheter, the end of the marker seed 659 may be notched, or the marker seed may be a gold tube that is filled with epoxy. Desirably, the distal end of the distal marker seed 659 is notched to prevent it from blocking access to the opening of the intraluminal connector 646, and the proximal end of the proximal marker seed is notched.

In addition to the radiation therapy doses disclosed in the above-cited patent application 08/628,231, the following radiation therapy doses may be administered to the patient: dose 14Gy,2 mm in a container having a diameter of about 2.7 to 3.2 mm; or 18Gy,2 mm in a container having a diameter of about 3.2 mm to 4.0 mm.

It may be necessary or desirable to determine the position of the treatment unit 658 and the identifier seed 659 relative to the quartz sleeve 518 in the delivery device 500 at a particular time during the radiation treatment process. For example, the user may need to verify that all 12 treatment units 658 and two flag seeds 659 are in the quartz sleeve 518 before delivering the treatment units to the distal end of the catheter 647, and additionally, for safety reasons, must be certain that all treatment units 658 and flag seeds 659 are in the quartz sleeve 518 before closing the needle valve 578a and disconnecting the catheter 647 from the delivery device 500.

To determine that all of the treatment units 658 and marker seeds 659 are in the quartz sleeve 518, an electronic detection system is provided in the delivery device 500 that determines whether a distal gold marker seed 659 is present at a single location in the quartz lumen 572. This electronic detection system operates similar to the detection system previously described to determine and indicate whether the treatment unit 658 is within the quartz sleeve 518. However, the measures taken by the electronic detection system to achieve the end result are slightly modified to produce a simpler, more efficient system and a more accurate indication of the treatment unit 658 and the location of the identifier seeds 659a and 659 b.

The system employs colorimetry to detect the gold marker seeds by shining light of different wavelengths onto the small area of the gold marker seeds that should be present in the quartz shell 518 and then measuring the reflectivity. Depending on the way the reflectivity varies with wavelength, the system determines whether a gold object (gold logo) or a non-gold object (stainless steel seed, background, or saline filled lumen) occupies the area. If a gold flag seed is detected, it is reasonably certain to conclude that this is the distal flag seed 659b and that all therapy units proximal to the distal flag seed 659b are also in the quartz housing. To improve the confidence that all of the seeds are in the quartz housing 518, an electronic sensor may be provided to determine whether the two identification seeds 659a and 659b are properly positioned in the quartz housing 518. However, this requires more space in the conveyor housing to accommodate the added electronic and optical components.

In practice, the light-sensitive device is not photosensitive to the blue and red light, and therefore the intensity of this or that light must be adjusted by a fixed compensation factor to achieve the condition that the electrical output of the light-sensitive device is the same as for the two colors. This technique is well known to those skilled in the art of optoelectronic devices and so it will be appreciated in the remainder of this description that wherever there is an indication that the intensity of blue and red light is equal, this means that their equality is measured by the output of the light sensitive device.

In addition to detecting the presence or absence of a gold marker seed at a particular location in the quartz lumen 572, the electronics wait for the power button 506 to be pressed in a low power state, then flash the indicator Light Emitting Diodes (LEDs)508a and 508b for about 4.7 seconds after the power button is pressed to indicate that the LEDs508a and 508b and the electrical ground 664 are running, and indicate whether a gold marker is detected by illumination of one of the two indicator Light Emitting Diodes (LEDs)508a and 508b, and finally automatically return to a low power state after 5 minutes to conserve battery power or restart a 5 minute timing cycle if the button 506 is pressed once during the 5 minutes.

The electronic system is powered by a 6V battery pack 664 comprising two 3V lithium batteries connected in series to generate +6V power. The output may also be converted to the-6V power required to generate the electronics. Examples of such batteries include Sanyo CR-P2, Panasonic CR-P2, and Duracell DL 223A. For safety protection, the battery is connected in series with a fuse. The upper conveyor half 502a can be removed to replace the battery pack as needed.

The power feed is controlled by a sleep circuit. Application of power causes the sleep circuit to close, which in turn sequentially cuts off the power supply feed so that only enough power is available to maintain system operation. The On-Switch (On-Switch)666 is a Single Pole Double Throw (SPDT) push button Switch 506. When the switch 666 is closed by briefly pressing the button 506 from outside the transmission 500, the sleep circuit wakes up, turning on the power feed 668,670, one source producing +5V power and the other source producing-5V power. The generated power is first acted upon by starting a countdown of an internal clock 672 (driven by a 27.3 hertz counter) set for a time of 5 minutes. At the end of the 5 minutes, the power feed 668,670 is cut off and the sleep circuit becomes inactive until the next time switch 666 is closed. If button 506 is pressed during a 5 minute timing period, the timing period is reset to maintain power for longer than 5 minutes. The internal clock 672 may be set by selecting one of several durations from existing designs. Each time the 5 minute clock 672 is started, a 4.7 second test phase 674 also begins, and a 3.4 hz oscillator 676 is started, which is derived from a 3.5 khz oscillator 690. A 3.4 hz oscillator 676 and a 4.7 second time 674 are applied to indicator LED driver 677 to cause the two indicator LEDs508a and 508b (one green and the other amber) to flash simultaneously at 3.4 hz for 4.7 seconds. This action is equivalent to informing the user that the battery 664 and indicator LEDs508a and 508b are operating properly. After the 4.7 second test period 674, the system enters its normal detection state.

The detection state utilizes the optical characteristics of stainless steel (material encapsulating the radioisotope) and gold (marker seed material or gold-plated material), and the optical characteristics of different reflectivities generated by the irradiation of red light and blue light on each of stainless steel and gold. The optics of the system include, a blue light emitting diode 678 using gallium nitride (GaN), a red light emitting diode 680 using gallium phosphide (GaP), a photosensor 682 containing a photodiode and an integrated amplifier, a GRIN lens 684, and a second photosensor 686, all of which are housed in an assembly 564 with a quartz sleeve 518 mounted therein. In fig. 51C, the first photosensor 682 is oriented perpendicular to the quartz sleeve 518, and the blue and red leds 678,680 are each on one side of the first photosensor 686, oriented at an angle to the photosensor. The conveyor inner channel 688 guides light emitted from the light emitting diode 678,680 to a target site on the quartz sleeve 518 and also guides reflected light back to the first photosensor 682. The GRIN lens is positioned between the quartz sleeve 518 and the first photosensor 682 to focus light onto the quartz sleeve 518 where the distal gold mark 659b should be present when all of the therapy units 518 are in the quartz sleeve 518. The GRIN lens then produces an image that is approximately focused on the surface of the photodiode. The axes of the GRIN lens, the red-blue led and the first photosensor must all intersect at the same point on the axis of the quartz housing 518, or very close to this point, in order to reliably determine the presence or absence of a gold marker seed.

The present system employs blue and red leds 678,680 that emit blue and red light at peak wavelengths of 450 nm and 700 nm, respectively. At 450 nanometers, stainless steel has a reflectivity of greater than 90%, while gold has a reflectivity of about 35%; at 700 nanometers, both stainless steel and gold have a reflectance greater than 90%. This means that stainless steel reflects blue and red light substantially equally well, while gold reflects red light well, but reflects blue light poorly (in fact gold absorbs blue light). Therefore, the blue/red ratio of the reflected light is measured to determine whether a gold object, in this case a gold mark, falls within the viewing zone of the light sensing device.

Analog clock oscillator 690, having an oscillation frequency of 3.5 khz, operates through a bi-stable multivibrator 692(Flip flop) in which its frequency is divided into two portions to generate two signals, each having a frequency of 1.75 khz, to alternately flash blue and red leds 678,680 (180 out of phase). One of the two signals is applied to the blue led driver 694 and the other signal is applied to the red led driver 696, so that each led 678,680 is driven at approximately 1.75 khz. Therefore, when the blue and red light emitting diodes 678,680 alternately flash and extinguish, the time for which they flash and the time for which they extinguish are equal. The flashing blue and red light is initiated by the led 678,680 traveling through the channel 688 in the assembly 564 and through the quartz sleeve 518 to the target site where the distal gold marker should be located when all seeds are in the quartz lumen 572. If a stainless steel seed or fluid occupies the target site, then both blue and red light get equally good reflection (about 96%). If nothing fills quartz lumen 572 at the target site, the background, as long as it is not colored, also reflects blue and red light, similar to stainless steel. If a gold marker seed is located in the target site, then red light is reflected and most of the blue light is absorbed. The first photosensor 682, which is comprised of a photodiode and an integrated amplifier, is optically connected to the target site in the quartz sleeve 518 through a GRIN lens, allowing the photosensor 682 to measure the reflectance of each of the blue and red light. The blue/red ratio of the reflected light from the measured reflectance is used to determine whether a gold mark is present.

The window 516 disposed along the top 502a of the conveyor 500 allows ambient light to also reflect off objects in the field of view of the light-sensing device 682. The photosensor 682 will detect ambient light in addition to blue and red light. Ambient signals superimposed on the respective blue and red diode 678,680 signals may affect the output of the photosensitive device 682. The photosensor 682 must operate only with light coming through the transparent window 516; therefore, the signal generated by the ambient light source is excluded from the system. This can be accomplished by using a high pass filter 698, a buffer 700, a synchronous detector and a low pass filter 704. A high pass filter removes all DC (direct current) light signals (e.g. daylight or flash); the buffer assists the sync detector in mitigating background interference by providing a low impedance excitation. The synchronous detector is a line that is synchronized with the blue and red led pulses. The synchronous detector processes the blue and red signals using the same 1.75 khz oscillator used to drive blue led 678, which removes all but those signals belonging to blue and red leds 680 and converts the resulting AC signal to a DC signal. The pulse amplitude corresponds to how much light is reflected off the target site, and the DC voltage is inversely proportional to the blue/red ratio of the reflected light. In the presence of gold in the target site, the DC voltage output is nominally zero. In the presence of other colors in the target site, the output is a non-zero voltage. The final step of filtering out the ambient light signal is to remove the ripple on the DC signal from the synchronous detector by using a low pass filter.

The system is designed to produce a nominally zero voltage in the case of gold detection (a positive non-zero voltage in the case of stainless steel detection or background) because the zero signal is unaffected by any gain encountered along the signal path (zero times any value is always zero); so nothing of the zero signal may go outside the window of deviation (Tolerance window) established according to the reference voltage (zero) to be detected. The null signal is more reliable than a non-zero voltage since it is less affected by variations within the system, such as mechanical tolerances and temperature changes. After setting the red led, the only adjustment needed to make the output voltage zero when the gold mark occupies the target site is to adjust the intensity of the blue led 678. Two signals of the same amplitude produce a zero voltage AC. Conversely, when the blue and red leds 678,680 emit light at the same intensity and gold reflects red light and absorbs blue light, the photosensor 682 sends a signal with a different amplitude (blue signal at high amplitude and red signal at low amplitude) which is converted to a non-zero DC voltage. To produce a zero signal in the presence of gold, rather than stainless steel, must produce the same amount of reflection for both blue and red light. This can be achieved by increasing the excitation of blue led 678 while keeping the excitation of red led 680 constant, so that blue led 678 emits light at a stronger intensity than red led 680. The amount of excitation that should be enhanced is an amount that results in the same amplitude for both the blue and red reflected light. By enhancing the intensity of the blue light by a certain percentage, gold now reflects blue light as well as red light, and in comparison, gold absorbs blue light when the red and blue leds 680,678 have the same excitation. The gold now reflects equal amounts of blue and red light, which produces no AC signal from the photosensitive device 682, thus forming a zero signal. On the other hand, the reflection of stainless steel is brighter in the case of blue light, because the blue led driver 694 is enhanced; the blue signal is greater than the red signal and the resulting square wave produces a non-zero DC voltage. To ensure that the stainless steel treatment unit and the background always produce a non-zero output voltage, they must be uncolored or blue colored in order to be able to reflect blue light and absorb red light, which is contrary to the behavior of gold.

When the DC signal is at nominal zero voltage, the system will indicate that gold has been detected. In actual operation, however, the DC signal is rarely at zero voltage due to certain variations within the system. A positive threshold detector 706 is provided in the system to compare the threshold reference voltage to the filtered and smoothed DC signal (where a true window detector with zero-centered positive and negative thresholds is not required because the signal produced by the stainless steel seed, saline and quartz lumens is found to always be positive). The buffered +2.5V reference voltage is run through a voltage divider 710 followed by a Unity gain buffer 712 to generate a margin reference voltage WIN + 714. The threshold detector 706 receives the DC signal and determines whether it exceeds a positive threshold (e.g., +450 millivolts). If the signal does not exceed the threshold, the threshold detector 706 determines that the signal is consistent with the presence of gold. The threshold value may be altered to change the systematic variation with respect to error. After the signal passes through the threshold detector 706, the decoded signal enters two drivers for the indicator leds508a and 508 b. If the decode signal indicates that gold is present, the green LED 508a located along the top 502a of the transfer device 500 in the quartz holder 730 emits light, indicating to the user that all of the treatment units are in the quartz housing 518. If the decode signal indicates that no gold is present, amber light emitting diodes 508b disposed along the top 502a of the transfer device 500 in the quartz holder 730 emit light, indicating to the user that not all of the treatment units may be in the quartz housing 518.

Both the blue and red leds 678,680 are temperature sensitive. The red led output decreases significantly with increasing temperature and increases significantly with decreasing temperature. These temperature-induced changes in the output of the red led affect the blue/red ratio of the reflected light, potentially hindering the ability of the system to detect the presence or absence of gold. To stabilize the output of the red leds, a brightness control loop is provided to regulate the output and compensate for temperature effects to stabilize the red led output. However, blue led 678 is fairly stable to temperature within the +10 ° to +35 ° normal operating temperature range; there is no need to provide a brightness control loop for the blue led 678. The red led brightness control circuit incorporates a second photosensor 686. The photosensor 686 compensates for temperature-induced changes in the output of the LEDs by "staring" at only the apex of the red LEDs 680 and then determining how much light it produces. The second light-sensing device 686 is positioned 90 deg. from the longitudinal axis of the red led 680. The red led output is detected in the same manner as the blue/red reflected signal, i.e., by a high pass filter 716, a buffer 718, a sync detector 720 and a low pass filter 722. The output DC signal is then passed through a non-switching DC amplifier 724 to set a control line gain 726. This signal either adds a positive gain or a negative gain to the reference signal (RED REF), which sets the RED led drive range. The conditioned signal to the red led driver keeps the red led output constant even though the actual amount of light may vary for a given current.

FIG. 60 is a block diagram showing electronics for colorimetric detection of a distal gold marker. These electronic components are disposed on two printed wiring boards, PCB a and PCBB. These printed wiring boards are shown on fig. 62A and 62B. For the test procedure, each printed circuit board is provided with a test connector which allows the signals and voltages in the lines to be accessed. The printed wiring board is stored in a plastic bag against moisture and mounted on the underside of a cradle in a conveyor. The electronics on the PCB A board are schematically shown in FIGS. 61A-61B, while the electronics on the PCB B board are schematically shown in FIGS. 61C-1 and 61C-2. Fig. 61D is a schematic diagram of a power distribution board mounted on top of the battery pack 664, while fig. 62C illustrates the mechanical layout of the power distribution board. The electrical connections between the various components of the detection system are shown in fig. 63A and an equivalent circuit is shown in fig. 63B, which also shows how the electrical connections are routed through the distribution printed wiring board and the micro-printed wiring board on which the photosensors 682 and 686 are mounted.

As a support for the electron source detection system, the window 516 above the quartz housing 518 allows the user of the delivery device 500 to visually detect whether all of the treatment units 658 are in the quartz housing 518 by either detecting the presence of a marker seed 659a and 659b on each side of the treatment units or counting the number of treatment units 658 and marker seeds 659 in the quartz housing 518. To facilitate visual inspection by the user, a magnifying lens 728 is secured above the assembly 564 and directly above the quartz lumen 572, as shown in fig. 48, 50, and 51C. The magnifier is also supported by quartz holder 730; therefore, indicator leds508a and 508b are also enlarged. The magnifying glass used can be magnified in one direction or in two directions, with a magnification of 2X or more. The magnifier is a concave-flat cylindrical glass lens. However, other lenses may be employed.

While the invention has been described above with reference to certain specific embodiments, it will be understood that various changes and modifications may be made without departing from the scope of the invention.

Claims (41)

1. A delivery device for use in an intraluminal treatment system for treatment of a selected site in a patient's body, at least one treatment element being advanced through a lumen in said delivery device into the lumen of a deployment catheter by the action of a pressurized fluid, said catheter having a proximal end with a catheter-integrated connector thereon for connecting the catheter to said delivery device, the invention being characterized in that: an actuator assembly including a valve member movable between a first position preventing entry of said treatment unit into the lumen of said catheter and a second position permitting entry of said treatment unit into the lumen of said catheter, said valve member being movable to said second position only when said catheter is connected to said delivery device.

2. The transfer device of claim 1 further comprising a central opening for receiving said connector, said actuator assembly further comprising a movable switch member biased into a first position that blocks movement of said valve member into said second position, said switch member being movable to a second position when said connector is received in said transfer device central opening to thereby allow movement of said valve member into said second position.

3. A transfer device according to claim 2, wherein said movable switch member is lockingly engaged with said connector when in said second position thereof.

4. A transfer device according to claim 3, wherein said actuator assembly has a portion thereon which prevents said switch member from being disengaged from said connector in said second position thereof.

5. The delivery device of claim 3, further comprising a release button for disengaging said switch member from said connector to allow said catheter to be removed from said delivery device, said release button being operable only when said valve is in said first position.

6. The delivery device of claim 2, wherein said actuator assembly further comprises a movable trigger member biased against insertion of said connector into said central opening and a release button movable into locking engagement with said connector when said connector is inserted into said central opening, said release button being operable to disengage said trigger member from said connector to allow removal of said catheter from said delivery device.

7. The delivery device according to claim 1, wherein said valve member further comprises a valve body having an aperture therein sized to permit said treatment unit to pass therethrough when said valve member is in said second position thereof.

8. A transfer device according to claim 1 wherein the valve member includes an elongate pin of smaller diameter than the transfer device lumen, the pin extending through the transfer device lumen so as to partially obstruct the transfer device lumen when the valve member is in its first position and to retract from extending through the transfer device lumen when the valve member is in its second position.

9. A transfer device according to claim 6 wherein the switch member moves into locking engagement with the connector when the valve member is moved into its second position, the switch member preventing movement of the valve member into its second position unless the connector has been fitted into the central opening of the transfer device.

10. The transfer device of claim 6 wherein said release button is inaccessible when said valve member is in said second position thereof.

11. The transfer device of claim 1, wherein the actuator assembly further comprises a movable retaining member having a U-shaped opening that engages a recess on the connector when the conduit is connected to the transfer device.

12. The delivery device of claim 8, wherein the pin is pressed through the delivery device with a pressure insufficient to damage the treatment unit if the pin touches the treatment unit.

13. The transfer device of claim 1, further comprising:

a cylindrical fluid control switch sized to fit into a central bore in the delivery device, the cylindrical fluid control switch having a plurality of fluid passageways in an enlarged diameter region thereof, whereby rotation of the fluid control switch causes pressurized fluid to be selectively introduced into the lumen of the delivery device.

14. A delivery device for use in an intraluminal treatment system for treatment of a selected site in a patient's body, at least one treatment element being urged by pressurized fluid from said delivery device into a lumen of a catheter, said delivery device being in communication with a source of pressurized fluid, comprising:

a pressure indicator comprising a transparent elongate cylindrical member having a first portion with a first internal diameter and being viewable by a user of the delivery device; a piston slidably received in said cylinder, said piston being sized to sealingly engage said first portion, said piston being pressed into said first portion of said cylinder; an inlet port is provided in the first portion and communicates with a source of pressurized fluid, such that relative fluid pressure data is visually provided based on the relative position of the piston in the first portion of the cylinder.

15. The transfer device of claim 14 wherein the elongated cylinder of the pressure indicator further comprises a second portion having a second inner diameter greater than the first inner diameter and a discharge port disposed in the portion communicating with the exterior of the transfer device, the piston being pressed into the first portion of the cylinder such that when the force of the pressurized fluid on the piston exceeds a predetermined value, the piston moves into the second portion of the cylinder to allow the pressurized fluid to flow through the piston and through the discharge port.

16. The transfer device of claim 15 wherein said pressure indicator further comprises a spring urging said piston into said first portion of said cylinder, said spring having a spring constant selected such that said spring exerts said predetermined force on said piston.

17. A transfer device according to claim 14, wherein the transparent cylinder is provided with graduations to enable viewing of the relative position of the piston in the cylinder.

18. The delivery device of claim 14, further comprising a pressure relief valve connected in parallel fluid communication with the pressure indicator.

19. A catheter having a proximal end and a distal end, for use in an intraluminal treatment system for treatment of a selected site in a patient's body, the system including a delivery device having a central bore for mounting said catheter and storing and advancing at least one treatment element into a lumen of said catheter, comprising:

a connector associated with the proximal end of the catheter, comprising at least one detent to secure the connector in the central bore of the delivery device, the detent being manually operable to release the catheter from the central bore of the delivery device.

20. The catheter of claim 18 wherein said detent comprises a projection extending axially from said connector.

21. A catheter for use in an intraluminal treatment system for treatment of a selected site within a patient's body, at least one treatment unit being movable by pressurized fluid, said catheter comprising an elongated tubular member having a proximal end and a distal end, and first and second lumens extending between said proximal and distal ends, said first and second lumens communicating at said distal end, said first lumen being sized to slidably receive said treatment unit, said second lumen having an elliptical cross-section.

22. The catheter of claim 21, further comprising at least one radiopaque marker to align the distal end and the at least one treatment unit to a selected site within a patient, the radiopaque marker being disposed in the first lumen at the distal end.

23. In a system for intraluminal treatment of a selected site in a patient's body including a catheter adapted for placement within an intracorporeal lumen and a delivery device integral with and external to said catheter for storing said treatment unit and introducing said treatment unit into said catheter, a method of detecting the presence of a treatment unit in said delivery device comprising:

encapsulating the treatment unit in a material having known reflective properties;

irradiating first and second light of different wavelengths onto the area of the delivery device where the treatment element is stored before and after introduction of the catheter;

measuring the intensity of the first and second light reflected from the region in the conveyor;

determining a reflected intensity ratio of the reflected first and second light;

comparing the reflected intensity ratio of the reflected first and second light to known reflection characteristics of a material encapsulating the treatment unit;

indicating whether the measured reflectance intensity ratio is substantially the same as the known reflectance property.

24. The method of claim 23, wherein the first and second lights are alternately illuminated at an area of the delivery device where the treatment unit is stored.

25. The method of claim 23, further comprising:

assembling the treatment units into a long column group, the treatment units being encapsulated in stainless steel;

arranging an identification unit at least at one end of the long group of the treatment units, wherein the identification unit is packaged in gold; and

illuminating said first light and said second light in said delivery device, said treatment unit identifying a region of seed storage before and after introduction of said catheter, said first light being blue light and said second light being red light.

26. The method of claim 23, further comprising:

activating a first color indicator light observable outside the conveyor when the measured reflectance intensity ratio is substantially the same as the known reflectance characteristic; and

a second color indicator light is activated to be visible outside the conveyor when the measured reflectance intensity ratio is substantially different from the known reflectance characteristic.

27. The method of claim 23, further comprising:

forming a signal corresponding to the intensity of reflection of light by said region of said conveyor;

filtering out any signal generated by ambient light; and

the signal formed by the first and second reflected light is compared to signals corresponding to known ratios of reflection of the encapsulation material at different wavelengths.

28. The method of claim 25, further comprising:

forming a signal corresponding to the intensity of reflection of light by said region of said conveyor;

filtering out any signal generated by ambient light; and

the signal formed by the first and second reflected light is compared to signals corresponding to known ratios of reflection of the encapsulation material at different wavelengths.

29. The method of claim 28, further comprising:

a signal is formed having a zero output voltage for light reflected from the identification cell.

30. The method of claim 29, wherein the zero output voltage for light reflected from the identification cell is formed by adjusting light intensity.

31. A system for detecting the presence or absence of an element at a target site, the element having a known reflectivity for light of different wavelengths, the system comprising:

a power source;

a first light source optically coupled to the target site for emitting light having a first wavelength;

a second light source optically coupled to the target site for emitting light having a second wavelength;

a first light sensing device optically coupled to said target site for measuring light reflected from said target site and generating a signal in response thereto;

a window detector for determining whether said generated signal is within a predetermined range corresponding to signals generated by first and second wavelengths of light reflected by said element; and

at least one indicator light that is activated if said generated signal is within said predetermined range.

32. The system of claim 31, wherein the first and second light sources each comprise a Light Emitting Diode (LED).

33. The system of claim 32, wherein said first light source comprises a blue led and said second light source comprises a red led.

34. The system of claim 32, wherein said first light-sensing device comprises a photodiode, a graded index lens for collecting light reflected from the target site and directing the collected light to said photodiode, and an amplifier integrated with said photodiode.

35. The system of claim 32, further comprising a brightness control circuit for stabilizing an output of the at least one light emitting diode, the brightness control circuit comprising:

a second photosensor optically connected to said light emitting diode;

a synchronous detector and filter for receiving the output of said second photosensitive device; and

an amplifier and integrator are provided for receiving the output of said second photosensor and setting a control loop gain which is added to a reference signal which sets the excitation range of said light emitting diode.

36. The system of claim 31, further comprising a filter for removing signals generated by said first light sensitive device due to ambient light.

37. The system of claim 36 wherein said filter includes a synchronous detector synchronized with signals corresponding to said first and second wavelengths of light for removing all asynchronous signals.

38. A catheter for use in an intraluminal treatment system for treatment of a selected site within a patient, at least one treatment element being movable under the influence of a pressurized fluid, said catheter comprising an elongated tubular member having a proximal end and a distal end, and first, second and third lumens extending between said proximal and distal ends, said first lumen being sized to slidably receive said treatment element and said third lumen being sized to receive a guidewire, the distal end of said third lumen being provided with a lining portion which prevents damage caused by said guidewire when said catheter is delivered over said guidewire to said selected site.

39. The system of claim 38, wherein said liner portion comprises a high density/low density polyethylene.

40. A catheter for use in an intraluminal treatment system for treatment of a selected site in a patient, at least one radiation treatment unit being movable by a pressurized fluid, the catheter including a shielding tube fitted over a portion of the proximal end of the catheter for shielding the radiation treatment unit as it passes in and out of the catheter.

41. In combination with at least one treatment unit usable in an intraluminal treatment system for treatment of a selected site in a patient, said treatment unit being stored in said delivery device and advanced by said delivery device under the influence of a pressurized fluid to said catheter, the improvement comprising at least one marker unit disposed at each end of the treatment unit, said marker unit having at least one notched end.