HK1101064B

HK1101064B - Pressure-propelled system for body lumen

Info

Publication number: HK1101064B
Application number: HK07109082.3A
Authority: HK
Inventors: 奥兹‧卡比利; 约西‧格罗斯; 鲍里斯‧德格蒂阿尔; 埃兰‧舒尔
Original assignee: G‧I‧视频有限公司
Priority date: 2004-01-09
Filing date: 2005-01-03
Publication date: 2010-06-25

Description

Pressure propulsion system for human body lumen

Cross Reference to Related Applications

This application is a continuation-in-part application and claims priority from:

(a) U.S. patent application entitled "Pressure-propelled system for body lumen" filed on 10/18/2004 by Cabiri et al;

(b) U.S. patent application No. 10/838,648 entitled "Pressure-propelled System for body lumen" filed on 5/3/2004 by Gross et al;

(c) U.S. patent application No. 10/753,424 entitled "Pressure-propelled System for body lumen" filed on 9.2004 by Gross et al.

This application claims priority from:

(a) us provisional patent application 60/607,986 entitled "Mechanical configurations of pressure-propelled systems for body lumens" filed on 8.9.2004 by Cabiri et al;

(b) U.S. provisional patent application 60/571,438 entitled "Omnidirectional and forward-looking imaging device" filed 5, 14.2004 by Dotan et al.

All of the above applications are assigned to the assignee of the present application and are incorporated herein by reference.

Technical Field

The present invention relates generally to a pressure propulsion system adapted to image a body lumen, such as the Gastrointestinal (GI) tract.

Background

A number of imaging devices are known for producing medical images of a body lumen, such as the Gastrointestinal (GI) tract. For example, endoscopy is widely used for observation, tissue photography, and collection of samples from diseased areas or elsewhere. For example, in one conventional method of examining the colon using an endoscope, the endoscope is typically manually inserted into the colon. In this manual technique, patients often complain of abdominal pain and distension due to stretching or over-widening of the colon, and have to stop the endoscopic procedure. In addition, sometimes the colon may also bleed and be accidentally perforated. Difficulties may be encountered in passing the endoscope through the sigmoid colon and into the descending colon, or through the splenic flexure of the colon, the transverse colon, the hepatic flexure of the colon, or sites affected by previous procedures. For these reasons, colonoscopy is usually performed only by a few highly skilled physicians, and the rate of patient pain and discomfort is high.

U.S. patent 5,337,732 to Grundfest et al, the disclosure of which is incorporated herein by reference, describes a robot for performing endoscopic procedures that includes a plurality of segments that are each connected to one another by an articulated joint. The actuators can move the segments toward and away from each other and change their angular orientation to enable the robot to move in an inchworm or snake-like manner through a body cavity or lumen of a patient. The inflatable bladders surrounding the segments are inflated to cause one temporarily affixed segment to bear against the lumen wall while the other segment moves. A compressed gas line connected to the rear end section provides compressed gas to inflate the bladder and optionally to drive the actuator. The tip section includes a television camera as well as a biopsy arm or other sensor and medical instruments.

U.S. patent application publication 2003/0168068 to Poole and Young, the disclosure of which is incorporated herein by reference, describes a method of lining a body lumen with a liner having two chambers, including (a) selectively controlling fluid pressure in a first chamber to cause eversion and advancement of the first chamber into the body lumen, and (b) selectively controlling fluid pressure in a second chamber to control the stiffness of the liner.

U.S. patent application publication 2003/0105386 to Voloshin et al and U.S. patent No. 6,485,409, the disclosures of which are incorporated herein by reference, describe endoscopic devices that include an inflatable sleeve that causes an endoscope to be advanced into the colon.

U.S. patent application publication 2002/0107478 to Wendlandt, the disclosure of which is incorporated herein by reference, describes a self-advancing catheter in which pressurization of an everted tube connected to the catheter will cause the catheter to advance into the body.

U.S. patent 6,702,735 to Kelly, the disclosure of which is incorporated herein by reference, describes an apparatus for moving a tool along a passageway. The tool is connected to the inflatable sheath so that the sheath extends into the passageway and carries the tool when inflated.

U.S. patent 5,259,364 to Bob et al, the disclosure of which is incorporated herein by reference, describes an endoscopic device that includes a flexible everted tube, wherein inflation of the everted tube causes an endoscope to be advanced into a body lumen.

U.S. patent No. 4,403,985 to Boretos, the disclosure of which is incorporated herein by reference, describes a catheter having a port near the distal end through which high pressure fluid forces the catheter to advance and divert.

U.S. patent 4,176,662 to Frazer, the disclosure of which is incorporated herein by reference, describes an endoscope having a propulsion mechanism and at least one transmitter at the distal end that transmits a train of energy wave pulses to track the position of the distal end. The propulsion mechanism comprises two radially expandable balloons, spaced apart by an axially expandable bellows, wherein only the front balloon is connected to the distal end, so that propulsion of the endoscope can be achieved by expanding and contracting the balloons in the appropriate sequence.

Us patent 4,148,307 to Utsugi, the disclosure of which is incorporated herein by reference, describes a tubular medical device having at least one cuff assembly comprising two cuffs disposed about a flexible sheath, spaced apart a predetermined distance and expandable only radially of the flexible sheath, and a deformable propellant cuff having a double rearward portion disposed about the sheath between the two cuffs. The flexible sheath is automatically advanced step by step within the body lumen as air is selectively introduced or inhaled from the three cuffs.

U.S. patent 5,906,591 to Dario et al, the disclosure of which is incorporated herein by reference, describes an endoscopic robot configured for insertion into a body lumen of a patient and movement within the lumen by inchworm-like motion.

U.S. patent 6,007,482 to Madni et al, the disclosure of which is incorporated herein by reference, describes an endoscope having a pair of telescoping sections at the distal end, one of which carries a camera and the two are alternately actuated by Bowden type pull wires to provide movement through a body passageway. The inflatable bladders provided for this movement are attached to the two cylindrical sections, respectively.

U.S. patent 5,662,587 to Grundfest et al, the disclosure of which is incorporated herein by reference, describes an endoscopic robot having multiple sections connected to one another. The traction part is attached to the wall of the lumen of the human body. Other portions include actuators to allow the endoscope to be locally deformed by bending, stretching, or some combination of bending and stretching. A method is provided for effecting sequential motion of the various sections to cause inchworm-like or snake-like movement, or a combination thereof, through a curved and flexible lumen. A compressed gas line connected to the rear portion provides compressed gas for insufflation in the lumen and optionally drives actuators for controlling operation of various portions of the endoscope.

U.S. patent 4,690,131 to Lyddy, jr, et al, the disclosure of which is incorporated herein by reference, describes a multi-element composite structure configured for use in an endoscope and capable of being deployed with an instrument at least partially into the lumen of a tubular body site such as the large intestine. A sheath is configured to be mounted over an endoscope. The endoscope and sheath are provided with selectively inflatable cuffs that are movable relative to one another by axially sliding the sheath over the endoscope.

U.S. patent 4,040,413 to Ohshiro, the disclosure of which is incorporated herein by reference, describes an endoscope comprising a tube having one or more inflatable balloons on its outer surface. A fiber optic bundle is passed through the tube body to the distal flexible portion of the tube body to view the interior of the body lumen. In the case where only one balloon is provided, the balloon is provided on the side of the tube body near the end of the tube body so as to enlarge the space in the lumen of the human body in a direction such that there is enough space in this direction to allow the flexible portion of the tube body to bend in that direction and thereby obtain a large field of view. Where more than one balloon is provided, one of the balloons is selectively inflated to enlarge the space in the body lumen in the desired direction. In one embodiment, an outer sleeve is disposed around the tube, the balloon is located on an outer surface of the outer sleeve, and the outer sleeve is slidable relative to the tube. The outer sleeve and the tube body can be inserted into the inner cavity of the human body by alternately inflating the balloon positioned on the outer sleeve and the balloon positioned on the tube body so as to be inserted into the inner cavity of the human body.

Ouchi, U.S. patent 6,503,192, the disclosure of which is incorporated herein by reference, describes an insertion facilitating device for an enteroscope. The device has a cylindrical body adapted to be inserted by an insertion portion of an endoscope while maintaining the anal sphincter of the patient in an open position. One end of the cylinder is provided with a conical opening. In one embodiment, the inner surface of the cylinder is provided with a pressure relief prevention ring made of a sponge material for preventing air leakage in the patient.

U.S. patent application publication 2003/0083547 to Hamilton et al, the disclosure of which is incorporated herein by reference, describes a method and apparatus for preventing longitudinal expansion of a body portion of an endoscopic sheath during inflation of an inflatable member. In one embodiment, a sheath assembly includes a body portion adapted to enclose a distal end of a cannula, and an expandable member coupled to the body portion and configured to expand radially outward from the body portion. The sheath assembly also includes an inflation prevention mechanism coupled to at least one of the expandable element and the body portion. An expansion prevention mechanism is described to prevent longitudinal expansion of the body portion during inflation of the expandable element. The expansion prevention mechanism may comprise, for example, a non-compliant element, a longitudinally extending portion, a reinforced spring element, a pressure relief device, or a suitable detent mechanism.

PCT publication WO 04/069057 to Gobel, the disclosure of which is incorporated herein by reference, describes a device for use in a healing process comprising a flexible double-walled inflatable tube section for enclosing a hollow space.

Gobel, U.S. patent application publication 2003/0000526, the disclosure of which is incorporated herein by reference, describes techniques for controlling a flow of ventilator breathing gas for assisting or controlling ventilation of a patient based on the airway pressure of the patient's tracheobronchial tubes. The technique involves inserting an airway tube, such as an endotracheal tube or tracheostomy tube, into the trachea. The tube is supplied with breathing gas and is equipped with an inflatable cuff and at least one lumen extending from the distal end of the tube all the way to the proximal end of the tube. The tube is configured to continuously or intermittently sense and evaluate the pressure within the envelope of the tube, thereby sensing the airway pressure. And controlling the breathing air flow of the respirator according to the detected pressure in the envelope.

PCT publication WO 03/045487 to Gobel, the disclosure of which is incorporated herein by reference, describes a balloon catheter for transurethral insertion into the bladder. The balloon includes a flexible catheter shaft to which an inflatable balloon element is secured and connected to an inflation channel incorporated in the wall of the catheter shaft. The balloon element and catheter shaft are made of polyurethane, polyurethane-polyvinyl chloride blend or similar polyurethane-based materials.

Disclosure of Invention

Some embodiments of the present invention provide an imaging system that is propelled by fluid pressure through a body lumen, such as the Gastrointestinal (GI) tract. Embodiments of the present invention will be described below with reference to the gastrointestinal tract, but it will be appreciated that the embodiments are not limited to use with the gastrointestinal tract, but may also be used with other body lumens. Unlike the prior art, which can inflate and affix balloons and similar devices to the wall of the gastrointestinal tract to overcome the low friction rate of the gastrointestinal tract, the embodiments of the present invention utilize the very low friction rate environment of the gastrointestinal tract to propel the imaging system, generally without the need for affixation.

To this end, according to one embodiment of the present invention, there is provided a system comprising: a guide at least partially insertable into a proximal opening of a body lumen, the guide comprising a first channel connectable to a source of fluid pressure; an elongated support body disposed for sliding movement through the guide member; a piston head mounted on the support body, wherein fluid pressure acting proximally to the piston head is higher than fluid pressure acting distally to urge the piston head and support body in a distal direction within a body lumen.

The system of this embodiment of the invention may have different features. For example, the piston head may be inflatable. The support body may include a second channel in fluid communication with the piston head and connectable to a source of fluid pressure to inflate the piston head. A blow-off pipe may pass through the piston head with an opening distal to the piston head through which fluid is discharged to the outside. An image-capturing device may be mounted on the support body, for example, distal to the piston head. The power supply tube may pass through the support body and may be connected to the image acquisition device. A fluid supply tube may pass through the support body and may be connected to a fluid source.

According to one embodiment of the invention, an auxiliary piston head can be mounted on the support body on the proximal side of the piston head first mentioned above. The auxiliary piston head may be inflatable and may be axially fixed to the support body at a fixed or variable distance from the first-mentioned piston head. The support body may include a third channel in fluid communication with the auxiliary piston head and connectable to a source of fluid pressure to inflate the auxiliary piston head.

There is provided, in accordance with an embodiment of the present invention, apparatus for use with a source of biocompatible fluid pressure, including:

an elongated support body configured for passage through a proximal opening of a body lumen;

a distal piston head connected to the distal portion of the support body and adapted to:

the support body directly contacts the wall of the lumen when inserted into the lumen,

advancing distally through a body lumen in response to pressure from a fluid pressure source,

fluid is encouraged to flow out of the lumen from a location within the lumen distal to the piston head.

In one embodiment, the outer surface of the piston head in contact with the wall of the lumen includes a low-friction coating adapted to facilitate sliding of the piston head against the wall of the lumen.

In one embodiment, the lumen includes a Gastrointestinal (GI) tract and the piston head is configured to directly contact a wall of the GI tract when the support body is inserted into the GI tract. For example, the gastrointestinal tract may include a colon, and the piston head may be configured to directly contact a wall of the colon when the support body is inserted into the colon.

In one embodiment, the apparatus includes a drainpipe, and the piston head is adapted to facilitate fluid flow out of the lumen through the drainpipe. For some applications, the drainpipe is shaped to define an inner diameter thereof of 1 to 5 mm, for example, 1 to 3 mm. In one embodiment, the vent tube is adapted to passively allow fluid to flow out of the lumen. Alternatively, the vent tube is adapted to be connected to a source of suction to actively facilitate fluid flow out of the lumen. For example, the blow-off pipe may be connected to a source of suction so that the pressure on the distal side of the piston head in operation of the apparatus is-5 mbar to +15 mbar.

In one embodiment, the piston head is configured to be inflated so as to reach and maintain direct contact with the wall of the colon.

For some applications:

(i) the device comprises an auxiliary piston head, which is connected to the support body at a position close to the distal piston head,

(ii) the auxiliary piston head is adapted to be inflated, thereby reaching and maintaining direct contact with the wall of the colon,

and (iii):

(a) at least one time while the support body is in the body lumen, the distal piston head is in a state of having been at least partially deflated, while, at the same time, the auxiliary piston head has been inflated and advanced distally through the colon in response to pressure from the fluid pressure source,

(b) at least one other time when the support body is in the body lumen, the auxiliary piston head is in a state of having been at least partially deflated while the distal piston head has been inflated and advanced distally through the colon in response to pressure from the fluid pressure source.

In one embodiment, the piston head is configured to intermittently at least partially deflate within the colon, thereby facilitating fluid flow from the lumen from a location in the lumen distal to the piston head.

In one embodiment, the apparatus includes a piston head pressure sensor adapted to detect pressure in the piston head. Alternatively or additionally, the apparatus comprises a distal pressure sensor adapted to detect a pressure in the colon distal to the piston head. Alternatively or additionally, the apparatus comprises a proximal pressure sensor adapted to detect pressure in the colon proximal to the piston head. For some applications, one, two or three such sensors are provided.

In one embodiment, the apparatus comprises:

a pressure sensor adapted to measure a first pressure associated with operation of the apparatus;

a control unit adapted to adjust a second pressure related to the operation of the apparatus in response to the measurement of the pressure sensor.

For example, the pressure sensor may be adapted to measure a pressure selected from the group consisting of: pressure distal to the piston head, pressure proximal to the piston head, and pressure in the piston head.

In one embodiment, the control unit is adapted to regulate the pressure measured by the pressure sensor. Alternatively, the control unit is adapted to regulate a pressure other than the pressure measured by the pressure sensor.

In one embodiment, the piston head is shaped to define a proximal bulge and a distal bulge in fluid communication with each other.

For some applications:

(a) a first one of the bulges is adapted to decrease in volume in response to a contractile action of the adjacent colon,

(b) the volume of the second one of the bulges is adapted to remain constant without variation in the diameter of the adjacent colon, even if the volume of the first bulge is reduced, and/or

(c) In a steady state, the pressure in the first and second bulges is equal, irrespective of whether the volume of the first bulge is reduced.

In one embodiment, the piston head is configured to be at an inflation pressure of 10 to 60 millibars (e.g., 20-50 millibars, or 30-45 millibars) as it advances through the colon. Alternatively or additionally, the piston head is adapted to advance through the colon in response to pressure from the fluid pressure source, the pressure being 30% to 100% of the inflation pressure. For example, the piston head may be adapted to advance through the colon in response to pressure from the fluid pressure source being 50% to 100% of the inflation pressure (e.g., 50% to 80% of the inflation pressure).

In one embodiment, the piston head is shaped to define a distally-narrowing portion and is configured for insertion into a colon such that a distal end of the distally-narrowing portion points in a distal direction when the piston head is in the colon. For some applications, a characteristic fully inflated diameter of a proximal base of the distal narrowed portion is greater than a diameter of at least a portion of the colon adapted to be traversed by the distal narrowed portion, such that when the base of the distal narrowed portion is located in this portion of the colon, the base is not fully inflated.

There is also provided, in accordance with an embodiment of the present invention, a method, including:

placing the distal piston head in direct contact with a wall of a body lumen;

applying fluid pressure to the distal piston head to advance the piston head distally through the body lumen;

In one embodiment, the method further comprises applying a low-friction coating to an outer surface of the piston head for contacting the wall of the lumen, the low-friction coating adapted to facilitate sliding of the piston head against the wall of the lumen.

In one embodiment, the lumen includes a Gastrointestinal (GI) tract and positioning the piston head includes positioning the piston head in direct contact with a wall of the GI tract. In one embodiment, the gastrointestinal tract includes a colon, and positioning the piston head includes positioning the piston head in direct contact with a wall of the colon.

In one embodiment, facilitating fluid flow comprises facilitating fluid flow out of the lumen through a blow-off tube extending from a position distal to the piston head to a position outside the lumen. For some applications, facilitating fluid flow out includes passively allowing fluid to flow through the drain and out of the lumen. Alternatively, facilitating fluid egress comprises actively draining fluid from the lumen. For example, actively expelling fluid may include applying a pressure of-5 mbar to +15 mbar to a location distal to the piston head.

In one embodiment, positioning the piston head in direct contact with the wall includes inflating the piston head to an extent to achieve and maintain direct contact with the wall of the colon.

In one embodiment, the method comprises:

positioning an auxiliary piston head proximal to the distal piston head;

inflating the auxiliary piston head to a degree sufficient to achieve and maintain direct contact with the wall of the colon;

at least partially deflating the distal piston head at least one time while the distal piston head is in the body lumen, such that at a time after the distal piston head deflates, the auxiliary piston head is inflated and advanced distally through the colon in response to the applied fluid pressure while the distal piston head is in a state that has been at least partially deflated;

at least one other time when the distal piston head is in the body lumen, at least partially deflating the auxiliary piston head such that at a time after the auxiliary piston head deflates, the distal piston head is inflated and advanced distally through the colon in response to the applied pressure while the auxiliary piston head is in a state that has been at least partially deflated.

In one embodiment, facilitating the flow of fluid out of the lumen comprises intermittently at least partially deflating the piston head.

In one embodiment, the method includes detecting pressure in the piston head, pressure in the colon distal to the piston head, and/or pressure in the colon proximal to the piston head.

In one embodiment, the method comprises:

detecting a first pressure associated with performing the method;

a second pressure associated with implementing the method is adjusted in response to detecting the first pressure.

For example, detecting the first pressure may include detecting a pressure selected from the group consisting of: pressure distal to the piston head, pressure proximal to the piston head, and pressure in the piston head.

For some applications, adjusting the second pressure includes adjusting the first pressure. Alternatively, adjusting the second pressure does not include adjusting the first pressure.

In one embodiment, inflating the piston head comprises inflating the piston head at an inflation pressure of 10 to 60 mbar. Alternatively or additionally, applying the fluid pressure includes setting the fluid pressure to 30% to 100% of the inflation pressure (e.g., 50% to 100% of the inflation pressure, or 50% to 80% of the inflation pressure).

In one embodiment, inflating the piston head comprises inflating the piston head at an inflation pressure of 20 to 50 mbar (e.g., 30 to 45 mbar).

directly contacting the wall of the lumen after insertion of the support body into the lumen,

facilitating fluid flow from the lumen from a location within the lumen distal to the piston head;

and an optical system having a distal end and a proximal end and comprising:

an image sensor disposed at a proximal end of the optical system;

an optical element having a distal end and a proximal end and shaped to define a lateral surface, at least a distal portion of the lateral surface being curved and the lateral surface being configured to provide an omnidirectional lateral viewing angle;

a convex mirror connected to the distal end of the optical element, wherein the optical element and the convex mirror have respective rotational shapes (rotational symmetry shapes) rotating around a common rotational axis.

For some applications, the convex mirror is shaped to define an opening therein through which distally directed light can pass.

There is also provided, in accordance with an embodiment of the present invention, apparatus for use with a biocompatible fluid pressure source, including:

an inflatable distal piston head connected to the distal portion of the support body, the distal piston head shaped to define a proximal bulge and a distal bulge in fluid communication with each other, the distal piston head for:

inflated after insertion of the support body into the lumen, so as to directly contact the wall of the lumen,

advancing distally through a body lumen in response to pressure from a fluid pressure source;

and a flexible blow-off tube passing through the proximal and distal bulges of the piston head, opening into one of the lumens at a location distal to the piston head and adapted to facilitate fluid flow out of that location.

There is also provided, in accordance with an embodiment of the present invention, apparatus, including:

a balloon connected to the distal portion of the support body and configured to directly contact a wall of the lumen after insertion of the support body into the lumen;

a hydrophilic substance disposed on an outer surface of the balloon.

a balloon connected to the distal portion of the support body and configured to directly contact a wall of the lumen after insertion of the support body into the lumen, the balloon having a characteristic thickness of no more than 20 microns.

For some applications, the characteristic thickness of the capsule does not exceed 10 microns.

is withdrawn proximally through the body lumen in response to pressure from the fluid pressure source.

For some applications, the support body is adapted to facilitate fluid flow out of the lumen from a location in the lumen proximal to the piston head.

There is also provided, in accordance with an embodiment of the present invention, apparatus for use with an elongated support body passing through a proximal opening of a body lumen, the apparatus including:

an annular balloon shaped to form an opening therein for passage of the support body therethrough, the balloon being inflatable to form a seal between the balloon and a wall of the body lumen adjacent the proximal opening;

first and second fluid pressure sources;

a first tube connected between a first pressure source and the interior of the bladder;

a second tube connected between a second pressure source and the lumen interior distal to the toroidal balloon.

For some applications, at least one of the first and second pressure sources is configured to be positioned outside a lumen of a human body.

an inflatable cuff shaped to define an opening therein for passage of a support body therethrough, the cuff adapted to form a seal with a wall of a body lumen adjacent the proximal opening when the cuff is in an inflated condition.

There is also provided, in accordance with an embodiment of the present invention, apparatus for use with a fluid source, the apparatus including:

an image capture device secured to the support body near the distal end thereof;

at least one fluid supply tube connected to the support body, the fluid supply tube being connected to a fluid source,

wherein the distal end of the support body is shaped to define one or more openings in fluid communication with the fluid supply tube, the openings being oriented to eject at least a portion of the image capture device upon supply of fluid by the fluid source.

There is also provided, in accordance with an embodiment of the present invention, apparatus for use with a body lumen having a proximal opening and a wall, the apparatus including:

an image capture device secured at a first vicinity of the distal end of the support body and adapted to provide an omnidirectional transverse viewing angle;

an inflation element fixed at a distal second vicinity position and adapted to increase the diameter of the support body at the second vicinity position to such an extent that the image acquisition device is positioned at a distance from the wall sufficient to achieve omnidirectional focusing of the image acquisition device.

There is also provided, in accordance with an embodiment of the present invention, apparatus for use with a body lumen having a proximal opening, the apparatus including:

first and second fluid pressure sources;

a distal inflatable piston head connected to the distal portion of the support body and configured and adapted to directly contact a wall of the lumen after insertion of the support body into the lumen;

a first channel in fluid communication with a first pressure source and a proximal portion of the lumen proximal of the piston head;

a second passage in fluid communication with a second pressure source and the piston head;

first and second pressure sensors adapted to measure pressure in the proximal portion of the lumen and pressure in the piston head, respectively;

a control unit adapted to advance the piston head distally in the lumen by:

when the first pressure source applies pressure to the lumen proximal portion,

the second pressure source is actuated to regulate the pressure in the piston head to equal the pressure in the proximal portion of the lumen plus a positive value.

For some applications, the device includes a third channel in fluid communication with a portion of the lumen distal to the piston head and a location outside the lumen.

a piston head connected to the distal portion of the support body and adapted to:

the support body forms a pressure seal with the wall of the lumen after insertion into the lumen,

the apparatus is configured to facilitate fluid flow out of the lumen from a location within the lumen distal to the piston head, thereby facilitating distal advancement of the piston head;

and an optical system coupled to the support body near the distal portion, the optical system having a distal end and a proximal end and comprising:

an image sensor disposed at a proximal end of the optical system;

In one embodiment, the lumen includes a Gastrointestinal (GI) tract, and the bearing body is configured to fit through a proximal opening of the GI tract. In one embodiment, the gastrointestinal tract includes a colon, and the bearing body is configured to fit through a proximal opening of the colon.

In one embodiment, the piston head is configured to directly contact the wall of the gastrointestinal tract after the bearing body is inserted into the gastrointestinal tract.

For some applications, the convex mirror is shaped to define an opening therein through which distally directed light can pass. For some applications, the optical element is shaped to define a distal recess at its distal end. For some applications, the optical element is shaped to define a proximal recess at its proximal end. For some applications, the optical system includes a distal lens positioned distal to the mirror, the distal lens having a rotational shape that rotates about the common axis of rotation. For some applications, the optical system is configured to provide different magnifications for distally directed light passing through a distal end of the optical system to the image sensor and for lateral light passing through a curved distal portion of a lateral surface of the optical element to the image sensor.

For some applications, the outer surface of the piston head forming a pressure seal with the wall of the gastrointestinal tract includes a low-friction coating adapted to facilitate sliding of the piston head against the wall of the gastrointestinal tract.

For some applications, the apparatus includes a fluid source, and at least one fluid supply tube connected to the support body, the fluid supply tube being in fluid communication with the fluid source, the distal portion of the support body being shaped to define one or more openings in fluid communication with the fluid supply tube, the openings being oriented to eject at least a portion of the optical element upon supply of fluid by the fluid source.

For some applications, the device comprises an inflatable element fixed in the vicinity of the distal portion of the support and adapted to increase the diameter of the support in said vicinity to such an extent as to position the optical element at a distance from said wall sufficient to achieve omnidirectional focusing of the optical system.

In one embodiment, the apparatus comprises a drainpipe, the apparatus being adapted to facilitate fluid flow out of the gastrointestinal tract through the drainpipe. For some applications, the vent tube is adapted to passively allow fluid flow out of the gastrointestinal tract. Alternatively, the vent tube is adapted to be connected to a source of suction to actively facilitate fluid flow out of the gastrointestinal tract.

In one embodiment, the piston head is configured to be inflated to form and maintain a pressure seal with the wall of the gastrointestinal tract. For some applications, the piston head is configured to intermittently at least partially deflate in the gastrointestinal tract, thereby facilitating passage of fluid out of the gastrointestinal tract at a location in the gastrointestinal tract distal to the piston head. For some applications, the piston head is shaped to define a proximal bulge and a distal bulge in fluid communication with each other.

For some applications, the apparatus includes a piston head pressure sensor adapted to detect pressure in the piston head. For some applications, the piston head pressure sensor is configured to be disposed in the piston head. Alternatively, a piston head pressure sensor is configured and adapted to be disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the piston head pressure sensor is configured to be disposed outside of the gastrointestinal tract.

an inflatable piston head connected to the distal portion of the support body, the piston head being shaped to define proximal and distal bulges in fluid communication with each other, the piston head being for:

inflated after insertion of the support body into the lumen so as to form a pressure seal with the wall of the lumen,

advancing distally through a body lumen in response to pressure from a fluid pressure source.

For some applications, a first one of the bulges is adapted to decrease in volume in response to contraction of the adjacent gastrointestinal tract, and a second one of the bulges is adapted to remain constant without a change in diameter of the adjacent gastrointestinal tract, even when the volume of the first bulge decreases, and the pressures in the first and second bulges are equal in steady state, regardless of whether the volume of the first bulge decreases.

For some applications, the diameter of the distal bulge is substantially equal to the diameter of the gastrointestinal tract. For some applications, the distal bulge is 3 to 5 centimeters in length. For some applications, the piston head is shaped to further define at least one bulge in addition to the first and second bulges.

For some applications, the piston head is shaped to define a middle portion where the proximal and distal bulges join. For some applications, the diameter of the intermediate portion is equal to 10% to 40% of the diameter of the distal bulge.

In one embodiment, the apparatus comprises a flexible bleeder tube passing through the proximal and distal bulges of the piston head, the opening being located in the gastrointestinal tract at a location distal to the piston head and adapted to facilitate distal advancement of the piston head by facilitating fluid flow from that location. For some applications, the apparatus includes a suction source adapted to actively facilitate fluid flow from the location.

a hydrophilic substance disposed on an outer surface of the balloon.

For some applications, the balloon is shaped to define a proximal bulge and a distal bulge in fluid communication with each other.

a balloon connected to the distal portion of the support body and configured to be adapted to directly contact the wall of the lumen after insertion of the support body into the lumen, an outer surface of the balloon in contact with the wall of the lumen including a low-friction coating adapted to facilitate sliding of the balloon against the wall of the lumen.

For some applications, the low-friction coating includes a lubricant.

For some applications, the characteristic thickness of the capsule does not exceed 10 microns. For some applications, an outer surface of the balloon in contact with the wall of the gastrointestinal tract includes a low-friction coating adapted to facilitate sliding of the balloon against the wall of the gastrointestinal tract. For some applications, an outer surface of the capsule in contact with the wall of the gastrointestinal tract includes a hydrophilic substance adapted to facilitate sliding of the capsule against the wall of the gastrointestinal tract.

In one embodiment, the lumen includes a Gastrointestinal (GI) tract and the piston head is adapted to form a pressure seal with a wall of the GI tract after the support body is inserted into the GI tract. In one embodiment, the gastrointestinal tract comprises a colon and the piston head is adapted to form a pressure seal with a wall of the colon after insertion of the support body into the colon.

For some applications, the piston head is shaped to define a proximal bulge and a distal bulge in fluid communication with each other.

For some applications, the apparatus includes a pressure applying tube in fluid communication with:

(a) one of the gastrointestinal tracts is located at a distal position distal to the piston head, and (b) a source of fluid pressure, the pressure-applying tube being adapted to direct pressure to the distal position.

For some applications, the apparatus comprises:

a fluid source;

an image capture device connected to the support near the distal end of the support;

at least one fluid supply tube connected to the support body, the fluid supply tube being in fluid communication with a fluid source,

the distal end of the support body is shaped to define one or more openings in fluid communication with the fluid supply tube, the openings being oriented to eject at least a portion of the image capture device upon supply of fluid by the fluid source.

In one embodiment, the device is adapted to facilitate passage of one of the fluid gastrointestinal tracts out of the gastrointestinal tract at a location proximal to the piston head. For some applications, the apparatus includes a vent in fluid communication with the proximal location and an outside of the gastrointestinal tract, the vent adapted to facilitate fluid flow from the proximal location to the outside to reduce pressure at the proximal location. For some applications, the vent tube is adapted to passively allow fluid flow out of the proximal location. For some applications, the apparatus includes a source of suction connected to the drainpipe and adapted to actively facilitate fluid flow from the proximal location.

In one embodiment, the piston head is configured to be inflated to form and maintain a pressure seal with the wall of the gastrointestinal tract. For some applications, the apparatus includes a piston head pressure sensor adapted to detect pressure in the piston head. For some applications, the piston head pressure sensor is configured to be disposed in the piston head. For some applications, a piston head pressure sensor is configured to be adapted to be disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the piston head pressure sensor is configured to be disposed outside of the gastrointestinal tract.

For some applications, the device includes a distal pressure sensor adapted to detect pressure in the gastrointestinal tract distal to the piston head. For some applications, the distal pressure sensor is configured to be disposed distally of the piston head. For some applications, the distal pressure sensor is configured to be adapted to be disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the distal pressure sensor is configured to be adapted to be disposed outside the gastrointestinal tract.

For some applications, the device includes a proximal pressure sensor adapted to detect pressure in the gastrointestinal tract proximal to the piston head. For some applications, the proximal pressure sensor is configured to be disposed adjacent the piston head. For some applications, the proximal pressure sensor is configured to be adapted to be disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the proximal pressure sensor is configured to be adapted to be disposed outside of the gastrointestinal tract.

For some applications, the device includes a pressure sensor adapted to measure a first pressure associated with operation of the device; a control unit adapted to adjust a second pressure related to the operation of the apparatus in response to the measurement of the pressure sensor. For some applications, the pressure sensor is adapted to measure a pressure selected from the group consisting of: pressure distal to the piston head, pressure proximal to the piston head, and pressure in the piston head.

an annular balloon shaped to form an opening therein through which the support body passes, the balloon being configured for at least partial insertion into the proximal opening and being expandable to form a pressure seal between the balloon and a wall of the body lumen adjacent the proximal opening;

first and second fluid pressure sources;

In one embodiment, the body lumen comprises a colon, the proximal opening comprises a rectum, and the balloon is configured for at least partial insertion into the rectum and is inflatable to form a pressure seal between the balloon and a wall of the colon.

For some applications, at least one of the first and second pressure sources is configured to be adapted to be positioned outside the colon.

For some applications, the device comprises a ring to which the balloon is connected, said ring being adapted to be pushed against the rectum and being shaped so as to form an opening therein for the passage of the support body.

For some applications, the first pressure source comprises an electro-dynamic fluid pressure source. Alternatively, the first pressure source comprises a manually operated fluid pressure source. For some applications, the manually operated pressure source comprises a syringe.

an inflatable cuff shaped to define an opening therein for passage of the support body, the cuff adapted to form a pressure seal with a wall of the body lumen adjacent the proximal opening when in an inflated condition.

In one embodiment, the body lumen comprises a colon, the proximal opening comprises a rectum, and the support body is configured to be adapted to pass through the rectum of the colon.

In one embodiment, the body lumen includes a colon, and the support body is configured to fit through a proximal opening of the colon.

For some applications, the distal end of the support body is shaped to define 4 to 10 openings through which fluid supplied by the fluid source may flow. For some applications, the openings are circumferentially arranged around the distal end of the support body. For some applications, the openings are arranged at a circumferential angle to create a vortex around the image capture device when fluid is supplied by the fluid source.

For some applications, the image capture device includes an optical element shaped to define a lateral surface configured to provide an omnidirectional lateral viewing angle, the opening being oriented to eject at least a portion of the lateral surface of the optical element. For some applications, the optical element is shaped to define a forward facing surface configured to provide a forward viewing angle, and the opening is oriented to eject at least a portion of the forward facing surface of the optical element.

an elongated support body configured to fit through the proximal opening of the lumen;

an inflation element fixed at a distal second vicinity position and adapted to increase the diameter of the support body at the second vicinity position to such an extent that the image acquisition device is positioned at a distance from the wall of the lumen sufficient to achieve omnidirectional focusing of the image acquisition device.

In one embodiment, the lumen includes a Gastrointestinal (GI) tract, and the bearing body is configured to fit through a proximal opening of the GI tract.

For some applications, the inflation element is adapted to increase a diameter of the support at the second proximate location such that the image capture device is spaced at least 15 millimeters from the wall.

For some applications, the inflation element comprises an expandable sponge. Alternatively or additionally, the inflation element comprises a set of one or more rings selected from the group consisting of inflatable rings and expandable rings. Alternatively or additionally, the inflation element comprises an inflatable balloon.

In one embodiment, the gastrointestinal tract includes a colon, and the bearing body is configured to fit through a proximal opening of the colon. For some applications, the inflation element is adapted to increase the support diameter at the second proximate location to 30 to 45 millimeters.

first and second fluid pressure sources;

an inflatable piston head connected to the distal portion of the support body and adapted to form a pressure seal with a wall of the lumen after insertion of the support body into the lumen;

first and second pressure sensors adapted to measure a first measurable pressure in the proximal portion of the lumen and a second measurable pressure in the piston head, respectively;

a control unit adapted to advance the piston head distally in the lumen by:

with the first pressure source applying a first applied pressure to the lumen proximal portion,

the second measurable pressure in the piston head is adjusted to equal the first measurable pressure in the proximal portion of the lumen plus a positive value by actuating the second pressure source to apply the second applied pressure.

In one embodiment, the piston is configured and adapted to directly contact the wall of the gastrointestinal tract after the bearing body is inserted into the gastrointestinal tract.

For some applications, the device includes a third channel in fluid communication with a portion of the gastrointestinal tract distal to the piston head and a location outside of the gastrointestinal tract.

For some applications, the diameter of the first channel is 3 to 6 millimeters.

For some applications, the first pressure sensor is configured to be disposed adjacent the piston head. Alternatively, for some applications, the first pressure sensor is configured and adapted to be disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the first pressure sensor is configured to be adapted to be disposed outside the gastrointestinal tract.

For some applications, the second pressure sensor is configured to be disposed in the piston head. For some applications, the second pressure sensor is configured and adapted to be disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the second pressure sensor is configured to be adapted to be disposed outside the gastrointestinal tract.

For some applications, the positive value is 1 to 5 mbar. For some applications, the positive value is 1.5 to 2.5 mbar.

For some applications, the control unit sets a second measurable pressure in the piston head at an initial value by actuating the second pressure source to apply the second application pressure prior to applying the first application pressure. For some applications, said initial value is 5 to 15 mbar and the control unit is adapted to set the second measurable pressure at 5 to 15 mbar. For some applications, the control unit is adapted to adjust the second measurable pressure to be equal to the greater of: (a) the initial value, and (b) a first measurable pressure plus the positive value.

is advanced distally through the body lumen in response to pressure applied to the outer surface of the distal piston head by a fluid pressure source, such as a gas pressure source.

In one embodiment, the lumen includes a Gastrointestinal (GI) tract and the distal piston head is adapted to form a pressure seal with a wall of the GI tract after the support body is inserted therein. In one embodiment, the gastrointestinal tract comprises a colon, and the distal piston head is adapted to form a pressure seal with a wall of the colon after insertion of the support body into the colon.

In one embodiment, the distal piston head is configured to directly contact a wall of the gastrointestinal tract after the bearing body is inserted into the gastrointestinal tract.

For some applications, the outer surface of the distal piston head forming a pressure seal with the wall of the gastrointestinal tract includes a low friction coating adapted to slide the distal piston head against the wall of the gastrointestinal tract.

For some applications, the apparatus comprises:

a fluid source;

an optical element attached near the distal portion of the support body;

the distal portion of the support body is shaped to define one or more openings in fluid communication with the fluid supply tube, the openings being oriented to eject at least a portion of the optical element upon supply of fluid by the fluid source.

For some applications, the apparatus comprises:

an optical system comprising an optical element configured to provide an omnidirectional transverse viewing angle;

an inflation element fixed in the vicinity of the distal portion of the support and adapted to increase the diameter of the support in said vicinity to such an extent as to position the optical element at a distance from said wall sufficient to achieve omnidirectional focusing of the optical system.

In one embodiment, the apparatus is adapted to facilitate distal advancement of the distal piston head by facilitating fluid flow out of the gi tract from a location within the gi tract distal to the distal piston head. For some applications, the apparatus is adapted to facilitate passage of an amount of fluid out of the gastrointestinal tract from the distal location, the amount of fluid passage being sufficient to maintain a pressure of less than 10 mbar at the distal location. For some applications, the apparatus is adapted to facilitate at least 100cc of fluid flow out of the gastrointestinal tract from the distal location during each minute of distal advancement of the distal piston head. For some applications, the apparatus is adapted to facilitate at least 300cc of fluid flow out of the gastrointestinal tract from the distal location during each minute of distal advancement of the distal piston head.

For some applications, the apparatus is adapted to facilitate at least 3cc of fluid flow out of the gastrointestinal tract from the distal location during each centimeter of distal advancement of the distal piston head. For some applications, the apparatus is adapted to facilitate at least 10cc of fluid flow out of the gastrointestinal tract from the distal location during each centimeter of distal advancement of the distal piston head.

For some applications, further comprising a bleeder, the apparatus being adapted to facilitate fluid flow from the gastrointestinal tract out of the distal location in the gastrointestinal tract through the bleeder. For some applications, the drainpipe is shaped to define an inner diameter of the drainpipe of 1 to 3 mm. For some applications, the vent tube is adapted to passively allow fluid to flow out of the gastrointestinal tract from the distal location in the gastrointestinal tract.

For some applications, the vent tube is adapted to be connected to a source of suction to actively facilitate fluid flow from the gastrointestinal tract from the distal location in the gastrointestinal tract. For some applications, the blow-off pipe is adapted to be connected to a source of suction so that the pressure distal to the distal piston head is-5 mbar to +15 mbar in operation of the apparatus.

For some applications, the apparatus further comprises a suction source connected to the drainpipe and adapted to actively facilitate fluid flow from the gastrointestinal tract from the distal location in the gastrointestinal tract. For some applications, the suction source is adapted to maintain a pressure of-5 mbar to +15 mbar distal to the distal piston head.

For some applications, the distal piston head is adapted to be inflated to form and maintain a pressure seal with a wall of the gastrointestinal tract, and the distal piston head is adapted to be intermittently at least partially deflated within the gastrointestinal tract, thereby facilitating fluid flow out of the gastrointestinal tract from a location in the gastrointestinal tract distal to the distal piston head.

In one embodiment, the distal piston head is configured to be inflated to form and maintain a pressure seal with the wall of the gastrointestinal tract. For some applications, the apparatus includes an auxiliary piston head coupled to the support body at a location proximal to the distal piston head; the auxiliary piston head is adapted to be inflated so as to form and maintain an auxiliary pressure seal with the wall of the gastrointestinal tract; and (a) at least one time when the support body is in the gastrointestinal tract, the distal piston head is in a state of having been at least partially deflated while the auxiliary piston head has been inflated and advanced distally through the gastrointestinal tract in response to pressure from the fluid pressure source, (b) at least one other time when the support body is in the gastrointestinal tract, the auxiliary piston head is in a state of having been at least partially deflated while the distal piston head has been inflated and advanced distally through the gastrointestinal tract in response to pressure from the fluid pressure source.

For some applications, the device includes a piston head pressure sensor adapted to detect pressure in the distal piston head. For some applications, the piston head pressure sensor is configured to be disposed in the distal piston head. For some applications, a piston head pressure sensor is configured to be adapted to be disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the piston head pressure sensor is configured to be disposed outside of the gastrointestinal tract. For some applications, the device includes a distal pressure sensor adapted to detect pressure in the gastrointestinal tract distal to the distal piston head. For some applications, the distal pressure sensor is configured to be disposed distally of the distal piston head. Alternatively, for some applications, the distal pressure sensor is configured to be adapted to be disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the distal pressure sensor is configured to be adapted to be disposed outside the gastrointestinal tract.

For some applications, the apparatus includes a proximal pressure sensor adapted to detect a first measurable pressure in a proximal portion of the gastrointestinal tract proximal to the distal piston head. For some applications, the device includes a distal pressure sensor adapted to detect pressure distal to the distal piston head. For some applications, the proximal pressure sensor is configured to be disposed adjacent the distal piston head.

For some applications, the proximal pressure sensor is configured to be adapted to be disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the proximal pressure sensor is configured to be adapted to be disposed outside of the gastrointestinal tract. For some applications, the apparatus includes a piston head pressure sensor adapted to detect a second measurable pressure in the distal piston head. For some applications, the pressure source comprises a first pressure source adapted to apply a first applied pressure to a proximal portion of the gastrointestinal tract, the apparatus comprising:

a second pressure source adapted to apply a second application pressure into the distal piston head;

a control unit adapted to advance the distal piston head distally in the gastrointestinal tract by:

with the first pressure source applying a first applied pressure to the proximal portion,

the second measurable pressure in the distal piston head is adjusted to equal the first measurable pressure in the proximal portion of the gastrointestinal tract plus a positive value by actuating the second pressure source to apply the second applied pressure.

For some applications, the device includes a pressure sensor adapted to measure a first pressure associated with operation of the device; a control unit adapted to adjust a second pressure related to the operation of the apparatus in response to the measurement of the pressure sensor. For some applications, the pressure sensor is adapted to measure a pressure selected from the group consisting of: pressure distal to the distal piston head, pressure proximal to the distal piston head, and pressure in the distal piston head. For some applications, the control unit is adapted to regulate the pressure measured by the pressure sensor. For some applications, the control unit is adapted to regulate a pressure other than the pressure measured by the pressure sensor.

For some applications, the distal piston head is shaped to define a proximal bulge and a distal bulge in fluid communication with each other.

For some applications, the distal piston head is configured to be at an inflation pressure of 10 to 60 millibars as it is advanced through the gastrointestinal tract. For some applications, the distal piston head is adapted to advance through the gastrointestinal tract in response to pressure from a fluid pressure source, the pressure being 30% to 100% of the inflation pressure. For some applications, the distal piston head is adapted to advance through the gastrointestinal tract in response to pressure from a fluid pressure source that is 50% to 100% of the inflation pressure.

For some applications, the distal piston head is configured to be adapted at an inflation pressure of 20 to 50 mbar when advanced through the gastrointestinal tract. For some applications, the distal piston head is configured to be adapted at an inflation pressure of 30 to 45 mbar when advanced through the gastrointestinal tract. For some applications, the distal piston head is adapted to advance through the gastrointestinal tract in response to pressure from a fluid pressure source, the pressure being 30% to 100% of the inflation pressure. For some applications, the distal piston head is adapted to advance through the gastrointestinal tract in response to pressure from a fluid pressure source that is 50% to 100% of the inflation pressure. For some applications, the distal piston head is adapted to advance through the gastrointestinal tract in response to pressure from a fluid pressure source that is 50% to 80% of the inflation pressure.

For some applications, the distal piston head is shaped to define a distal constriction and is configured for insertion into the gastrointestinal tract such that a tip of the distal constriction points in a distal direction when the distal piston head is in the gastrointestinal tract. For some applications, a characteristic fully-inflated diameter of a proximal base of the distal constriction is greater than a diameter of at least a portion of the gastrointestinal tract adapted to be traversed by the distal constriction, such that the base of the distal constriction is not fully inflated when the base is located in this portion of the gastrointestinal tract.

a biocompatible fluid proximal pressure source configured and adapted to be in fluid communication with the lumen proximal portion proximal of the piston head and to supply a pressure sufficient to advance the support body distally through the body lumen.

In one embodiment, the lumen includes a Gastrointestinal (GI) tract and the piston head is adapted to form a pressure seal with a wall of the GI tract. In one embodiment, the gastrointestinal tract comprises a colon and the piston head is adapted to form a pressure seal with a wall of the colon.

In one embodiment, the piston head is configured to directly contact a wall of the gastrointestinal tract.

For some applications, the device further includes a first channel through which the proximal pressure source is in fluid communication with the proximal portion of the gastrointestinal tract.

For some applications, the apparatus includes a piston pressure source configured to be in fluid communication with the piston head and to supply pressure to the piston head to inflate the piston head.

For some applications, the apparatus includes a second passage through which the piston pressure source is in fluid communication with the piston head.

For some applications, the apparatus includes a proximal pressure sensor adapted to measure pressure in a proximal portion of the gastrointestinal tract; a piston pressure sensor adapted to measure pressure in the piston head.

For some applications, the device includes a proximal pressure sensor adapted to measure pressure in a proximal portion of the gastrointestinal tract. For some applications, the proximal pressure sensor is configured to be disposed adjacent the piston head. Alternatively, for some applications, the proximal pressure sensor is configured and adapted to be disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the proximal pressure sensor is configured to be adapted to be disposed outside of the gastrointestinal tract.

For some applications, the apparatus includes a piston pressure sensor adapted to measure the pressure in the piston head. For some applications, the piston pressure sensor is configured to be disposed in the piston head. For some applications, the piston pressure sensor is configured to be adapted to be disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the piston pressure sensor is configured to be adapted to be disposed outside the gastrointestinal tract.

For some applications, the apparatus includes a bleeder tube configured and adapted to be in fluid communication with a distal portion of the gastrointestinal tract distal to the piston head and in fluid communication with the outside of the gastrointestinal tract to facilitate distal advancement of the piston head by facilitating fluid flow out of the gastrointestinal tract from the distal portion. For some applications, the device includes a distal pressure sensor adapted to measure pressure in a distal portion of the gastrointestinal tract. For some applications, the distal pressure sensor is configured to be disposed distally of the piston head. For some applications, the distal pressure sensor is configured to be adapted to be disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the distal pressure sensor is configured to be adapted to be disposed outside the gastrointestinal tract.

For some applications, the apparatus is adapted to facilitate passage of an amount of fluid out of the gastrointestinal tract from the distal portion, the amount of fluid being sufficient to maintain a pressure of less than 10 mbar at the distal portion.

For some applications, the vent tube is adapted to passively allow fluid to flow out of the gastrointestinal tract from the distal portion.

For some applications, the apparatus includes a suction source connected to the drain adapted to actively facilitate fluid flow from the distal portion out of the gastrointestinal tract.

For some applications, the apparatus is adapted to facilitate at least 100cc of fluid to flow out of the gastrointestinal tract from the distal portion during each minute of distal advancement of the piston head. For some applications, the apparatus is adapted to facilitate at least 300cc of fluid to flow out of the gastrointestinal tract from the distal portion during each minute of distal advancement of the piston head.

For some applications, the apparatus is adapted to facilitate at least 3cc of fluid flow out of the gastrointestinal tract from the distal portion for each centimeter of distal advancement of the piston head. For some applications, the apparatus is adapted to facilitate at least 10cc of fluid flow out of the gastrointestinal tract from the distal portion for each centimeter of distal advancement of the piston head.

a biocompatible fluid proximal pressure source configured and adapted to be in fluid communication with the lumen proximal portion proximal of the piston head and to supply pressure sufficient to advance the support body distally through the body lumen;

a piston head pressure sensor adapted to detect a piston head pressure in the piston head, the piston head pressure sensor disposed proximate the proximal opening of the lumen and in fluid communication with the piston head interior.

For some applications, the piston head pressure sensor is configured and adapted to be in fluid communication with the interior of the piston head through a passage having a proximal end disposed proximate to the proximal opening of the gastrointestinal tract.

For some applications, the piston head pressure sensor is configured to be disposed outside of the gastrointestinal tract.

For some applications, the apparatus includes a biocompatible fluid piston head pressure source configured and adapted to be in fluid communication with the interior of the piston head through a channel, and a piston head pressure sensor configured and adapted to be in fluid communication with the interior of the piston head through the channel.

For some applications, the device includes a proximal portion pressure sensor adapted to detect pressure in a proximal portion of the gastrointestinal tract and disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the proximal portion pressure sensor is configured to be adapted to be disposed outside of the gastrointestinal tract.

For some applications, the device includes a distal portion pressure sensor adapted to detect a distal portion pressure of a distal portion of the gastrointestinal tract distal to the piston head and disposed proximate a proximal opening of the gastrointestinal tract. For some applications, the distal portion pressure sensor is configured to be adapted to be disposed outside the gastrointestinal tract.

forming a pressure seal between the piston head and the wall of the body lumen;

advancing the piston head distally through the body lumen by:

fluid pressure is applied to the outer surface of the piston head,

and providing an omnidirectional transverse view from near the piston head.

forming a pressure seal between a wall of a body lumen and a piston head shaped to define a proximal bulge and a distal bulge in fluid communication with each other;

the piston head is advanced distally through the body lumen by applying fluid pressure to an outer surface of the piston head.

providing an elongate support having a balloon attached to a distal portion thereof, the balloon having a hydrophilic substance disposed on an outer surface thereof;

the elongated support body is inserted through the proximal opening of the body lumen such that the balloon directly contacts the wall of the lumen.

providing an elongate support having a balloon attached to a distal portion thereof, the balloon having an outer surface with a low friction coating adapted to facilitate sliding of the balloon against the wall of the lumen;

the elongated support body is inserted through the proximal opening of the body lumen such that the outer surface of the balloon directly contacts the wall of the lumen.

providing an elongate support having a balloon attached to a distal portion thereof, the balloon having a characteristic thickness of no more than 20 microns;

forming a pressure seal between the piston head and the wall of the body lumen;

fluid pressure is applied to the outer surface of the piston head to withdraw the piston head proximally through the body lumen.

inserting a toroidally-shaped balloon at least partially into the proximal opening of the body lumen;

inflating the balloon to form a seal between the balloon and a wall of the body lumen adjacent the proximal opening;

inserting said elongated support body through an opening through the balloon into the lumen;

pressure is applied to the interior of the lumen distal to the balloon.

inserting an inflatable cuff at least partially into a proximal opening of a body lumen;

inflating the cuff to form a seal with a wall of a body lumen adjacent the proximal opening;

the elongated support body is inserted into the lumen through an opening through the cuff.

inserting an elongated support body through a proximal opening of a body lumen, the support body having an image capture device secured thereto near a distal end thereof;

ejecting fluid from one or more openings in the distal end of the support body toward at least a portion of the image capture device.

inserting an elongated support through a proximal opening of a body lumen, said support having an image capture device secured thereto at a first, proximal location at a distal end thereof for providing an omnidirectional transverse viewing angle;

the support diameter at the second, proximal position of the distal end is increased to such an extent that the image capture device is positioned at a distance from the wall of the lumen sufficient to achieve omnidirectional focusing of the image capture device.

forming a pressure seal between the inflatable piston head and a wall of the body lumen;

measuring a first measurable pressure in a proximal portion of the lumen proximal of the piston head and a second measurable pressure in the piston head;

advancing the piston head distally through the lumen by:

a first applied pressure is applied to the lumen proximal portion,

the second measurable pressure in the piston head is adjusted to equal the first measurable pressure in the proximal portion of the lumen plus a positive value by applying a second applied pressure to the piston head.

forming a pressure seal between the distal piston head and a wall of the body lumen;

fluid pressure is applied to an outer surface of the distal piston head to advance the piston head distally through the lumen.

forming a pressure seal between the piston head and the wall of the body lumen;

applying fluid pressure to an outer surface of the distal piston head to advance the piston head distally through the lumen;

piston head pressure in the piston head is detected near the proximal opening of the lumen.

Drawings

The present invention will be more fully understood from the detailed description given below in conjunction with the accompanying drawings.

FIG. 1 is a simplified pictorial illustration of a system, constructed and operative in accordance with an embodiment of the invention, suitable for imaging a body lumen, such as the GI tract;

FIGS. 2 and 3 are simplified schematic diagrams of distal and proximal portions, respectively, of the system of FIG. 1;

FIG. 4 is a simplified schematic illustration of a support according to an embodiment of the invention in the system of FIG. 1, the cross-section being taken transverse to the longitudinal axis of the support;

FIGS. 5A, 5B and 5C are simplified schematic diagrams of the system of FIG. 1 illustrating three steps of an operational mode according to an embodiment of the present invention in which an inflatable piston head is inflated and deflated to clear an obstruction in a body lumen;

FIG. 6 is a schematic view of a system for a body lumen constructed and operative in accordance with an embodiment of the present invention;

FIG. 7 is a schematic view of an inflatable tapered balloon for use in accordance with an embodiment of the present invention;

FIG. 8 is a schematic view of a partially inflated conical balloon in a human body lumen according to an embodiment of the present invention;

figure 9A is a schematic cross-sectional view of a fully inflated portion of a cone-shaped balloon according to an embodiment of the present invention;

figure 9B is a schematic cross-sectional view of a tapered balloon portion inflation portion in accordance with an embodiment of the present invention;

FIGS. 10A and 10B are schematic illustrations of a system for use with a body lumen, constructed and operative in accordance with an embodiment of the invention;

FIGS. 11A and 11B are schematic illustrations of the multi-lobed piston head of FIGS. 10A and 10B, in accordance with an embodiment of the present invention;

FIG. 12 is a schematic cross-sectional view of an optical system according to an embodiment of the present invention;

FIGS. 13A and 13B are schematic illustrations of another system for a body lumen according to an embodiment of the present invention;

FIG. 14 is a schematic cross-sectional view of an interposer according to an embodiment of the present invention;

figure 15 is a schematic cross-sectional view of a cleaning system according to an embodiment of the present invention.

Detailed Description

Referring now to fig. 1-3, a system 10 constructed and operative in accordance with an embodiment of the present invention is shown.

As best shown in fig. 3, the system 10 may include a guide 12, which may be made of any medically safe material, such as, but not limited to, plastic or metal. Guide 12 may be formed with a first channel 14 that is connected to a source 16 of pressurized biocompatible fluid (fluid pressure source 16), such as, but not limited to, pressurized air, CO₂Or a source of water. Guide 12 may be at least partially inserted into a proximal opening 18 (e.g., rectum) of a body lumen 20 (e.g., colon). Guide 12 may include a ring 22 for pushing against proximal opening 18.

The guide member 12 may be formed with a through hole 24 through which an elongate support body 26 is arranged for sliding movement. An O-ring 28 may be provided for dynamically sealing the support body 26 during sliding movement relative to the guide 12. The support 26 may be any thin wire, tube, or the like, and may be made of any medically safe material, such as, but not limited to, a flexible plastic or metal. The support body 26, including its distal end, can be safely deflected and steered through the body lumen 20.

In one embodiment of the present invention, the guide 12 includes a microcapsular (microcuff) that forms a seal with the wall of the lumen 20 to maintain a positive pressure in the lumen 20. For example, the micro-envelope may comprise an envelope manufactured by Microcuff GmbH (Weinheim, Germany), and/or a micro-envelope described in the aforementioned PCT publication WO 04/069057, U.S. patent application publication 2003/0000526, and/or PCT publication WO 03/045487. The generation of the positive pressure will be described later.

Piston head 30 may be mounted on support body 26. The piston head 30 may be inflatable and may be made of any medically safe elastomeric material, such as, but not limited to, a bladder or membrane made of polyurethane or silicone rubber. An image capture device 32 may be mounted on support body 26 distal to piston head 30. Piston head 30 is typically secured to support body 26 and forms a seal therewith with O-ring 33, but may alternatively be positioned to slide on support body 26 until encountering some end stop that prevents further distal movement of piston head 30 (e.g., image capture device 32 may serve as an end stop). The image acquisition device 32 may include, but is not limited to, a video camera (e.g., of the CCD or CMOS type), or an X-ray, ultrasound, MRI, infrared and/or microwave imaging device.

Other therapeutic or diagnostic devices may be mounted on or in the support 26, such as, but not limited to, magnets, drug delivery devices (e.g., by iontophoresis), gene therapy devices, and the like.

The support body 26 may include a second channel 34 in fluid communication with the piston head 30 and connected to a fluid pressure source 36 (e.g., pressurized air or water) for inflating the piston head 30. For some applications, piston head inflation fluid pressure source 36 is adjusted to maintain a substantially constant pressure in piston head 30 regardless of changes in piston head volume that occur in response to changes in lumen 20 diameter.

A vent tube 38 may pass through or around piston head 30, having an opening 40 on the distal side of piston head 30 through which fluid may be vented to the outside. That is, the proximal end of the drainpipe 38 drains the fluid flowing through the guide 12 to the outside. For some applications, the proximal end of the drainpipe 38 may be connected to a source of suction (not shown) for drawing fluid through the drainpipe 38. The term "fluid" as used herein and in the claims includes both liquids and gases.

In one embodiment, a blow-off pipe 38 is not employed, but rather causes the piston head 30 to deflate (at least in part) intermittently and/or temporarily in response to excessive pressure accumulating distal of the piston head 30. The temporary deflation of the piston head allows distal pressure to be relieved through the passage 14, typically with the temporary removal of the passage 14 from the fluid pressure source 16.

An electrical power supply tube 42 (e.g., containing electrical wires, optical fibers, etc.) may pass through the support 26 to connect to the image capture device 32. Alternatively, the electrical and optical components of the image capture device 32 may have their own internal power supply, without the need for external wiring. The image capture device 32 may transmit and receive data to and from an external processor (not shown) in an unlimited manner. The elements of the system 10 may be fully automated by means of sensors and operated by closed or open loop control.

A fluid supply tube 44 may pass through the support body 26 and may be connected to a fluid source (not shown), such as pressurized water, to clean the area adjacent the image capture device 32, or in combination with the drain tube 38 to clean the body lumen 20 itself (e.g., the colon).

Experiments conducted by the inventors have shown that, as previously mentioned, the system is capable of safely and efficiently advancing a colonoscope or other tool through the colon of a 90 kg anaesthetised pig. In these experiments, elongated support 26 was substantially radiopaque, and its motion was tracked in real time by fluorescence imaging. The drainpipe 38 is used, and has an inner diameter of 2 mm. It is passively operated (not connected to a source of suction) to enable pressure build-up distal of the piston head 30 to vent to the outside.

In these experiments, a range of operating pressures were examined. The proximal pressure and the pressure in the piston head (intra-head pressure) are controlled and the value at which satisfactory movement of the piston head 30 is observed is recorded. In general, for an intra-head pressure in the range of 25 to 40 mbar, motion of piston head 30 is observed when the proximal pressure reaches 30-100% of the intra-head pressure.

Typically, no motion is observed when the proximal pressure is below a threshold. As the proximal pressure rises above the threshold, piston head 30 advances through the colon. If the proximal pressure rises significantly above the threshold pressure (e.g., 2-10 mbar above the threshold pressure), pressure relief occurs between piston head 30 and the wall of lumen 20 and advancement of piston head 30 stops. In response to this pressure relief, the proximal pressure drops, the blow-off tube 38 vents the excess accumulated distal pressure to the outside, and the movement of the piston head 30 resumes.

In one experiment, an inflatable piston head was formed of thin silicone and was shaped to have a distal bulge (lobe), a proximal bulge, and an intermediate portion connecting the distal and proximal bulges (see fig. 10A and 10B). For an intra-head pressure of 30 mbar, the piston head advances through the colon while the proximal pressure remains at 10 to 20 mbar. During the advancement of the piston head, the drainpipe 38 discharges the accumulated pressure to the outside due to the advancement of the piston head. At proximal pressures greater than about 20 mbar, leaks were observed around the piston. For an intra-head pressure of 40 mbar, the piston head is advanced through the colon, whether a straight portion or a curved portion of the colon, while the proximal pressure is maintained at 27 to 30 mbar. For straight portions of the colon, proximal pressures as low as 20 mbar are also sufficient to produce satisfactory movement of the piston head.

Although the advancement rate of the two-lobe piston head was found to vary with the selected pressure, in an experiment using a thin-walled two-lobe piston head, the 1.5 meter advancement of the colonoscope into the pig colon took a total of 2 minutes. In another experiment using a thick-walled two-bulge piston head, 1 minute 41 seconds of colonoscope advancement of 1.5 meters was spent as a result of an intra-head pressure of 70 mbar and a proximal pressure of 50 mbar. Thin wall piston heads suitable for use in embodiments of the present invention typically have a wall thickness of 10 to 100 microns, for example 50 microns or less than 20 microns, or less than 10 microns. Thick-walled piston heads of these embodiments of the invention typically have a piston head wall thickness greater than 100 microns, for example 150 microns or 250 microns.

In another experiment, the piston head was formed of polyurethane and was shaped like a cone, as described later with reference to fig. 7-9. In this experiment, satisfactory advancement of the piston head was obtained at a proximal pressure of 35 mbar, and an intra-head pressure of 35 mbar. Satisfactory progression is obtained in both straight and curved portions of the colon.

It should be noted that in these experiments, the piston head volume actively varied in response to changes in the diameter of lumen 20 while the pressure inside the head remained constant.

Referring now to fig. 1, 2, and 5A-C, the operation of system 10 is illustrated in accordance with an embodiment of the present invention. In this embodiment, the auxiliary piston head 46 may be mounted on the support body proximal to the distal piston head 30. Similar to piston head 30, auxiliary piston head 46 may be inflatable and may be axially fixed to support body 26 at a fixed distance from piston head 30. The auxiliary piston head 46 may be sealed against the support body 26 with an O-ring 47. The support body 26 may include a third channel 48 in fluid communication with the auxiliary piston head 46 and connected to a fluid pressure source 50 for inflating the auxiliary piston head 46.

System 10 may be inserted into the rectum with piston heads 30 and 46 initially deflated to facilitate insertion. Distal piston head 30 may then be inflated gently until it expands against the inner wall of body lumen 20. This configuration is shown in fig. 1. Pressurized fluid (e.g., air) from a fluid pressure source 16 may be introduced into the colon through the first passage 14 of the guide 12. The pressurized fluid creates a higher fluid pressure acting proximally on piston head 30 than on the distal side of piston head 30. The opening 40 of the drainpipe 38 may assist in creating a pressure differential across the sides of the piston head 30, either passively or actively by applying suction. This pressure differential propels piston head 30, along with support body 26, distally into the body lumen (in this case the colon), as indicated by arrow 60. The image acquisition device 32 can capture images of the body lumen 20 as the system 10 is operated therethrough.

In one embodiment of the invention, the techniques described herein for effecting advancement by creating a pressure differential are applied in the reverse manner to positively advance piston head 30 proximally with support body 26, i.e., to withdraw system 10 from lumen 20. Pressurized fluid (e.g., air) from a fluid pressure source is directed distally of piston head 30 via a pressure applying tube that passes through or around piston head 30. Alternatively, the drainpipe 38 is used as a pressure applying pipe during pullback. The pressurized fluid creates a higher fluid pressure acting distally on piston head 30 than proximally on piston head 30, thereby advancing the piston head and support proximally. A blow-off tube located between the proximal side of piston head 30 and the outside of the lumen may help create a pressure differential across the sides of piston head 30, either passively or actively by applying suction. Alternatively, the passage 14 may be used as a drainpipe during pullback.

As shown in fig. 5A, the system 10 may eventually reach an obstacle or sharp corner, as indicated by arrow 62. In this case, the proximal piston head 46 may be inflated and the distal piston head 30 may be deflated, as shown in fig. 5B. In this configuration, the pressurized fluid creates a higher fluid pressure acting proximally of the proximal piston head 46 than distally of the proximal piston head 46. This pressure differential advances the proximal piston head 46 distally with the support body 26, as indicated by arrow 64. This distal movement causes the distally reduced piston head 30 to move past the obstruction as shown in fig. 5B. System 10 continues its distal movement in body lumen 20 until proximal piston head 46 reaches the obstruction. Here, the distal piston head 30 may be inflated and the proximal piston head 46 may be deflated again, as shown in fig. 5C. Again, the pressurized fluid creates a higher fluid pressure acting proximally of distal piston head 30 than distally of distal piston head 30. The pressure differential advances system 10 distally in body lumen 20 and causes proximally reduced piston head 46 to move over the obstruction. This cycle may be repeated as many times as desired.

Referring now to FIG. 6, a system 68 constructed and operative in accordance with an embodiment of the present invention is shown. System 68 operates in substantially the same manner as system 10 described above with reference to FIGS. 1-4, i.e., distal piston head 30 is inflated until it contacts body lumen 20, thereby forming a seal between piston head 30 and lumen 20. Pressurized fluid is then introduced through first passage 14, creating a higher pressure on the proximal side of piston head 30 than the distal side of piston head 30, thereby causing a net force that causes piston head 30 to move distally. A sufficient net pressure causes piston head 30 to move distally with elongated support body 26 and tool 79. The tool 79 may include an imaging device, a biopsy device, or other equipment used in the body lumen 20.

Further, for some applications of the present invention, a suction source 78 is connected to opening 40 through drainpipe 38 to provide suction on the distal face of piston head 30, thereby facilitating movement of distal piston head 30. Providing suction at opening 40 may also be used in some applications to remove contents of the lumen, such as excess fluid or feces, which may impede movement of piston head 30. For some applications, suction may be used to reduce gas buildup on the distal side of piston head 30, which may be uncomfortable to the patient.

System 68 typically includes one or more pressure sensors, for example, to improve or optimize system performance, to allow system 68 to easily and quickly traverse lumen 20. In particular, the system 68 typically includes one or more of the following pressure sensors:

a first pressure sensor 70 adapted to measure the pressure acting on the proximal face of the distal piston 30;

a second pressure sensor 72 adapted to determine the inflation pressure of the distal piston head; and/or

A third pressure sensor 74 adapted to measure the pressure acting on the distal face of piston head 30.

For some applications, the three pressure sensors are connected to a pressure sensor bus 76 so that individual pressure readings can be sent to an electromechanical or mechanical control unit (not shown) that adjusts the various pressures, either automatically or using input from the system operator. For some applications, only one pressure sensor is included in system 68 (e.g., sensor 70, sensor 72, or sensor 74). For some other applications, two pressure sensors are included, with one sensor (e.g., sensor 70, sensor 72, or sensor 74) omitted.

For some applications, first pressure sensor 70 is positioned proximal to distal piston head 30, in the vicinity of piston head 30. Alternatively, first pressure sensor 70 is positioned adjacent fluid pressure source 16, typically outside the patient's body. In the latter configuration: (a) the first pressure sensor 70 is combined with the pressure source 16 or is disposed separately from the pressure source 16; and (b) first pressure sensor 70 is in fluid communication with the proximal portion of lumen 20 proximal of piston head 30, either through first passage 14 or through a separate passage (not shown) in fluid communication with first pressure sensor 70 and the proximal portion of lumen 20. The distal end of the single channel is configured to be positioned in a proximal portion of lumen 20, either near guide 12 or more distally in lumen 20, such as near piston head 30 proximal to piston head 30.

For some applications, second pressure sensor 72 is disposed within distal piston head 30. Alternatively, second pressure sensor 72 is positioned adjacent fluid pressure source 36, typically outside the patient's body. In the latter configuration, second pressure sensor 72 is in fluid communication with piston head 30, either through second passage 34 or through a separate passage (not shown) in fluid communication with second pressure sensor 72 and piston head 30.

For some applications, third pressure sensor 74 is disposed distal to distal piston head 30. Alternatively, the third pressure sensor 74 is positioned near a proximal opening of the drainpipe 38 (which is near the source of suction for applications where a source of suction 78 is provided), typically outside the patient's body. In the latter configuration: (a) the third pressure sensor 74 is combined with the suction source 78, or is positioned separately from the suction source 78; and (b) third pressure sensor 74 is in fluid communication with the distal portion of lumen 20 distal of piston head 30, either through blow-off tube 38 or through a separate passage (not shown) in fluid communication with third pressure sensor 72 and the distal portion of lumen 20.

For some applications, where third pressure sensor 74 is in fluid communication with a distal portion of lumen 20 through vent tube 38, a source, such as suction source 78, is adapted to periodically, such as every 5 to 15 seconds, such as every 10 seconds, generate a jet of fluid (i.e., liquid or gas) in vent tube 38 to purge any bodily matter that may enter the tube through opening 40 from the tube. Similarly, for some applications, where third pressure sensor 74 is in fluid communication with the distal portion of lumen 20 via a separate channel, an additional pressure source is connected to the proximal end of the separate channel to periodically generate a jet of fluid in the separate channel.

In some embodiments of the invention, system 68 may achieve satisfactory performance by maintaining a pressure of approximately 25 millibar proximal to piston head 30, approximately 5 millibar distal to piston head 30, and approximately 20 millibar internal to piston head 30. Suitably, typical ranges for these values are about +10 to +50 mbar, -5 to +15 mbar, and +10 to +60 mbar, respectively.

For some applications, as system 68 moves distally, the pressure inside piston head 30 is maintained such that the pressure differential across each side of piston head 30 is within about 5 millibars. For example, using the representative values listed above, the pressure differential across the piston head is 25 mbar-5 mbar-20 mbar. By maintaining the pressure inside piston head 30 within a 5 mbar pressure differential, the pressure inside piston head 30 is typically maintained at 15 to 25 mbar. If piston head 30 is constructed of a flexible but substantially non-elastic material (e.g., a material having an elongation of less than 10% when inflated at a pressure of less than 50 millibar, such as polyurethane), the pressure in piston head 30 may generally be maintained around this pressure differential. For embodiments in which piston head 30 is constructed of a flexible and resilient material (e.g., a material having an elongation greater than 10% when inflated at a pressure less than 50 millibars, including silicone), the pressure in piston head 30 is typically greater than this pressure differential.

In one embodiment of the present invention, the pressure inside piston head 30 is set at an initial value, such as about 5 to 15 millibars, for example, about 10 millibars, as system 68 is moved distally. The pressure proximal to piston head 30 increases, typically gradually, and at the same time, the pressure inside piston head 30 is adjusted to the greater of the two values: (a) its initial value, and (b) the pressure proximal to the piston head 30 plus a value, such as a constant value. Typically, the constant value is in the range of about 1 to about 5 mbar, for example about 1.5 to about 2 mbar, for example about 2 mbar. Once system 68 begins to advance distally, the pressure on proximal piston head 30 gradually decays or remains at a constant level, although pressure is continuously being applied by pressure source 16. The diameter of first passageway 14 is typically of a value small enough to prevent the proximal pressure of piston head 30 from increasing for an extended period of time as system 68 is advanced distally. For example, the diameter of the first channel may be between about 3 and about 6 millimeters. Generally, in this embodiment, the pressure in piston head 30 is controlled in substantially real time, while the pressure within piston head proximal lumen 20 does not have to be controlled in real time.

Other combinations of distal, proximal, and internal pressures of piston head 30 may be better suited for certain applications, and the above values are not meant to limit the various operating pressures of embodiments of the present invention. Further, for some applications of the present invention, the respective pressures acting on piston head 30 are adjusted according to the position of the lumen piston head.

Although only a distal piston head is shown in FIG. 6, it is to be understood that the scope of the present invention includes systems having a proximal piston head as shown in FIG. 1, as well as the various pressure control and measurement devices described above with reference to distal piston head 30 in FIG. 6.

Referring now to FIG. 7, an inflatable piston head 80 constructed and operative in accordance with an embodiment of the present invention is shown. The inflatable piston head 80 comprises an inflatable balloon in the general form of a body formed by rotation about an axis defined by the elongated support 26, with the distal end being smaller in diameter than the proximal end. The piston head 80 is typically constructed of a material that is flexible but substantially inelastic over the typical pressure ranges encountered so that the shape of the piston head does not change significantly due to elastic deformation as the piston head is inflated. Alternatively, piston head 80 comprises a flexible and resilient material. In some embodiments of the invention, the inflatable piston head 80 is conical, as shown in fig. 7. It should be noted that while the foregoing uses a taper formed by rotating a straight line about an axis of rotation, other shapes of the inflatable piston head 80 may be formed by rotating various curves about the axis of rotation. For example, a parabola or a circular arc may be used to create a suitable shape. In the description and claims of the present invention, all shapes that narrow toward the distal end are referred to as having a "distally narrowing portion".

For some embodiments of the invention, the base of the inflatable piston head 80 is flat. In some other embodiments, the base of the inflatable piston head 80 is curved, wherein the curved shape may be either concave or convex.

FIG. 8 illustrates one application of an inflatable piston head 80 in accordance with an embodiment of the present invention. Piston head 80 is typically inserted into lumen 20 in a deflated state and then inflated until in proper contact with the lumen. Due to the shape of inflatable piston head 80, once the piston head is fully pressurized, a majority of fully inflated portion 82 of the piston head does not substantially contact lumen 20, while a portion of partially inflated portion 84 of the piston head contacts lumen 20. A good seal between piston head 80 and lumen 20 is typically achieved where fully inflated portion 82 meets partially inflated portion 84.

Figures 9A and 9B illustrate cross-sections of a fully inflated portion and a partially inflated portion, respectively, according to embodiments of the present invention. The resistance of the lumen 20 to radial expansion prevents full inflation of the entire piston head (shown, for example, in fig. 7). As such, the partially inflated portion 84 typically exhibits some puckering over the entire length of its portion in contact with the lumen 20.

Inflatable piston head 80 is adjusted in response to changes in the diameter of lumen 20, i.e., more inflated as the diameter of the lumen increases, and deflated as the diameter of the lumen decreases, while maintaining satisfactory contact with the lumen. Because the inflatable piston head 80 is typically made of a material that is substantially inelastic, it is desirable to inflate the piston head with a relatively gentle pressure. The inflation pressure is selected to maintain a suitable seal between the piston head and the lumen without requiring excessive pressure to be applied to the lumen.

Figures 10A and 10B are schematic illustrations of a multi-lobed piston head 100 for use in a body lumen 20, constructed and operative in accordance with an embodiment of the present invention. In addition to the differences that will be noted, the devices and techniques described above with respect to other piston heads are generally applicable to piston head 100.

Piston head 100 includes a distal bulge 102 and a proximal bulge 104. The bulges 102 and 104 are joined to the intermediate part 106. In one embodiment, the dimensions of piston head 100 include: (a) a diameter D1 of distal bulge 102 that is substantially equal to the diameter of lumen 20 so as to form a satisfactory seal therewith, (b) a diameter D2 of intermediate portion 106 that ranges from about 10% to 40% of D1, and (c) a length D3 of distal bulge 102 that ranges from about 3 to 5 centimeters. It should be noted that although the multi-lobe piston head 100 includes only two lobes, the scope of the present invention includes multi-lobe piston heads having more lobes (e.g., 3,4, or 5 lobes).

The distal and proximal tympanites 102 and 104 are in fluid communication with each other through an intermediate portion 106. In a steady state, and at various levels of motion typically encountered while advancing through the colon, the pressure in the tympanostomy 102 is substantially equal to the pressure in the tympanostomy 104. Thus, the passage 34 and the fluid pressure source 36 (FIG. 2) regulate the pressure in both bulges substantially simultaneously. However, the diameters of the two bulges typically vary independently of each other in response to changes in the shape of the lumen 20 proximate each bulge. Typically, as with all inflatable piston heads described herein, fluid is actively added to or expelled from the piston head to maintain a substantially constant pressure in the piston head.

In one embodiment of the present invention, piston head 30 and/or support body 26 of system 10 and/or system 68 include a low-friction coating for reducing friction between piston head 30 and lumen 20, thereby facilitating movement of piston head 30 and/or support body 26 within lumen 20. For example, piston head 30 and/or support body 26 may include a biocompatible low-friction coating. Alternatively or additionally, piston head 30 and/or support body 26 include a hydrophilic coating. Additionally or alternatively, the low-friction coating includes a suitable lubricant.

Fig. 11A and 11B are schematic views of a multi-lobed piston head 100 according to an embodiment of the present invention. In FIGS. 11A and 11B, the following tubes are shown as previously described:

a second channel 34 in fluid communication with the two bulging sections 102 and 104 of the piston head 100 and connected to a fluid pressure source 36;

a blow-off pipe 38 passing through the bulges 102 and 104 of the piston head 100 and having an opening 40 located distally of the piston head 100 through which the fluid is discharged to the outside;

a fluid supply tube 44 that passes through the piston head 100 to clean the area near the image capture device 32, or, in combination with the drainpipe 38, to clean the body lumen 20 itself.

The second passage 34, drainpipe 38, and fluid supply pipe 44 are generally flexible to allow the piston head 100 to flex, as shown in fig. 11B.

Fig. 12 is a schematic cross-sectional view of an optical system 220 according to an embodiment of the present invention. For some applications, image capture device 32 includes an optical system 220. The optical system 220 includes an optical assembly 230 and an image sensor 232, such as a CCD or CMOS sensor.

The optical system 220 is typically configured to simultaneously provide forward and omnidirectional lateral viewing angles. Light emitted by the front end of the optical element 234 and light emitted by the lateral surfaces of the optical element travel through non-overlapping optical paths that are substantially separated from each other. The forward light and the transverse light are typically (but not necessarily) processed to produce two separate images, rather than a combined image. For some applications, forward viewing angles are primarily used to navigate within a body region, and omni-directional lateral viewing angles are primarily used to examine a body region.

The optical assembly 230 comprises at its distal end a convex mirror 240 having a rotational shape (rotationally symmetrical shape) with the same rotational axis as the optical element 234. Optical element 234 is typically shaped to define a distal recess 244 at the distal end of the optical element, i.e., through the middle of mirror 240. Alternatively, optical element 234 is shaped without recess 244, and mirror 240 includes a non-mirrored portion in the center thereof.

Typically, the optical assembly 230 also includes a distal lens 252 having the same axis of rotation as the optical element 234. For some applications, the optical assembly 230 also includes one or more proximal lenses 258, for example, two proximal lenses 258. A proximal lens 258 is disposed between the optical element 234 and the image sensor 232 to focus the optical fibers from the optical element onto the image sensor.

For some applications, optical system 220 is configured to provide an omnidirectional transverse viewing angle, but not a forward viewing angle.

For some applications, the hydrophobic coating is applied on one or more transparent surfaces of the optical assembly 220 that are in contact with the body lumen 20.

The techniques described herein may be used in combination with the techniques described in U.S. provisional patent application 60/571,438 entitled "omnidirectional and forward-looking imaging apparatus", filed on 14.5.2004, assigned to the assignee of the present application, and incorporated herein by reference.

Reference is now made to fig. 13A and 13B, which are schematic illustrations (not drawn to scale) of a system 310 according to an embodiment of the invention. System 310 is substantially similar to system 10 and/or system 68 except as described hereinafter. The image capture device 32 of the system 310 typically includes the optical system 220 described above with reference to fig. 12, or other omnidirectional imaging device. System 310 is typically advanced distally into lumen 20 using the techniques described above with reference to systems 10 and/or 68.

The system 310 is withdrawn in the proximal direction by: (a) inflating lumen 20 using conventional inflation techniques of withdrawing the endoscope, and (b) pulling support body 26 in a proximal direction. During withdrawal, the distal end of the system sometimes comes close to or in contact with the wall of lumen 20, as shown in fig. 13A. For example, the lumen 20 may be inflated to a diameter D1 of between about 40 and about 70 millimeters, and the initial distal diameter D2 of the system 310 near the image acquisition device 32 of between about 8 and about 15 millimeters. When system 310 is close to the wall of lumen 20, the distance between the lateral portions of optical system 220 of image capture device 32 may be less than the minimum focal length required for a clear omnidirectional lateral viewing angle.

The system 310 includes an inflation element 320 adapted to increase the distal diameter of the system 310 from D2 (fig. 13A) to D3 (fig. 13B). D3 is typically located between about 30 and about 45 millimeters. The increased distal diameter ensures that the distance between the image acquisition device 32 and the wall of the lumen 20 is large enough to enable focusing of an omnidirectional transverse image. For example, the increased distal diameter may ensure that the distance D4 between the central axis of the image acquisition device 32 and the wall of the lumen 20 is at least 15 millimeters. For some applications, the inflation element 320 comprises a sponge that expands when exposed to a liquid, for example. Alternatively, the inflation element 320 comprises a set of inflatable or expandable rings. Alternatively, the inflation element 320 comprises an inflatable balloon, typically contained within the body of the system 310.

Reference is now made to fig. 14, which is a schematic illustration of an inserter 330 for use with system 10 and/or system 68, in accordance with an embodiment of the present invention. The inserter 330 is configured and adapted for at least partial insertion into the proximal opening 18 (e.g., rectum) of a body lumen 20 (e.g., colon). Inserter 330 typically includes a circular ring 332 for abutting proximal opening 18, and a ring-shaped balloon 336 connected to ring 332. The ring 332 and the bladder 336 are shaped so as to define a through hole 334 in them through which the support body 26 is arranged to undergo sliding movement. Balloon 336 expands to form a seal between the balloon and the wall of lumen 20 near proximal opening 18 to help maintain the positive pressure generated in body lumen 20.

Inserter 330 includes a first channel 14 connected to a fluid pressure source 16 (e.g., as described above with reference to fig. 1-3), and a tube 338 for applying positive pressure to inflate balloon 336. The tube 338 is connected to a fluid pressure source 340, which may comprise an electrically powered fluid pressure source (e.g., provided in an operator compartment) or a manually operated fluid pressure source (e.g., a syringe). Where the fluid pressure source 340 comprises a syringe, the syringe is typically removed after the bladder 336 is inflated, and the tube 338 and/or bladder 336 are sealed to maintain pressure, for example, using a one-way valve (the valve not shown). For some applications, pressure source 16 and pressure source 340 are provided by a common fluid pressure source.

Referring now to fig. 15, a schematic diagram of a cleaning system 350 for use with system 10 and/or system 68 is shown, in accordance with an embodiment of the present invention. The cleaning system 350 is shaped to define one or more openings 360 (e.g., about 4 to about 10) to which the fluid supply tube 44 is connected. Opening 360 is disposed circumferentially around the distal end of support 26 and is oriented to eject at least a portion of image capture device 32. For some applications, where image capture device 32 includes optical system 220 as previously described with reference to fig. 12, opening 360 is typically oriented to eject at least a portion of the omnidirectional transverse portion of optical assembly 230, and, optionally, a portion of the assembly toward the distal portion. For some applications, opening 360 is positioned at a circumferential angle, thereby creating a vortex around image capture device 32.

Although in embodiments of the invention the piston head is described as being in direct contact with the wall of the GI tract, the scope of the invention includes establishing contact between the piston head and the wall of the GI tract through an intermediary, such as a sheath surrounding the piston head.

The techniques described herein may be used in combination with the techniques described in (a) U.S. patent application 10/838,648 entitled "pressure propulsion system for a body lumen" filed on 3.5.2004 of Gross et al and (b) U.S. patent application entitled "pressure propulsion system for a body lumen" filed on 9.1.2004 of Gross et al, which are assigned to the assignee of the present application and which are incorporated herein by reference.

It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the specification and which are not in the prior art.

Claims

1. An apparatus for use with a biocompatible fluid pressure source, comprising:

a guide at least partially insertable into a proximal opening of a body lumen, the guide comprising a channel connectable to a source of fluid pressure;

an elongated support body disposed for sliding movement through the guide member; and

an inflatable piston head mounted on the support body and configured to be advanced distally through a body lumen under a fluid pressure differential across the piston head when inflated, thereby advancing the piston head distally with the support body into the body lumen.

2. The apparatus of claim 1, wherein the fluid pressure differential is due to: fluid pressure introduced into the lumen through the passageway of the guide generates a higher fluid pressure acting proximally of the piston head than distally of the piston head.

3. The apparatus of claim 1, wherein the support body comprises a channel in fluid communication with the piston head and connectable to a source of piston pressure to inflate the piston head.

4. The apparatus of claim 3, further comprising an annular balloon shaped to form an opening therein for passage of the support body, the balloon being adapted to be at least partially inserted into the rectum and being inflatable to form a pressure seal between the balloon and a wall of the body lumen adjacent the rectum.

5. The apparatus of claim 1, wherein the lumen comprises a gastrointestinal tract, and the inflatable piston head is adapted to be inflated to form and maintain a pressure seal with a wall of the gastrointestinal tract after the support body is inserted into the gastrointestinal tract.

6. The apparatus of claim 5, wherein the gastrointestinal tract comprises a colon, the proximal opening comprises a rectum, and the piston head is adapted to form a pressure seal with a wall of the colon after the support body is inserted into the colon.

7. The apparatus of claim 5, wherein the piston head is configured and adapted to directly contact a wall of the gastrointestinal tract after the support body is inserted into the gastrointestinal tract.

8. The apparatus of claim 5, wherein an outer surface of the piston head forming a pressure seal with the wall of the gastrointestinal tract comprises a low friction coating adapted to facilitate sliding of the piston head against the wall of the gastrointestinal tract.

9. The apparatus of claim 1, wherein the piston head is shaped to define a first bulge and a second bulge in fluid communication with each other.

10. The apparatus of claim 9, wherein the volume of the first bulge is adapted to decrease in response to a constriction adjacent the gastrointestinal tract; the volume of the second bulge is adapted to remain constant without a change in the diameter of the adjacent gastrointestinal tract, even when the volume of the first bulge is reduced; in a steady state, the pressures in the first and second bulges are equal, irrespective of whether the volume of the first bulge is reduced.

11. The apparatus of claim 5, further comprising a pressure applying tube in fluid communication with a distal location in the gastrointestinal tract distal to the piston head and a source of fluid pressure, the pressure applying tube adapted to direct pressure to the distal location.

12. The apparatus of claim 1, further comprising an image capture device mounted on the support.

13. The apparatus of claim 12, further comprising:

a fluid source;

at least one fluid supply tube connected to the support body, the fluid supply tube being in fluid communication with a fluid source;

wherein the distal portion of the support body is shaped to define one or more openings in fluid communication with the fluid supply tube, the openings being oriented to clean at least a portion of the image capture device with fluid supplied by the fluid source.

14. The apparatus of claim 1, wherein the fluid pressure source comprises a gas pressure source, and the piston head is adapted to advance distally in response to gas pressure from the gas pressure source.

15. The apparatus of claim 1, further comprising a blow-off tube passing through the piston head having an opening distal to the piston head through which fluid is discharged outside the body lumen.

16. The apparatus of claim 15, wherein the blow-off pipe is in fluid communication with a proximal location in the lumen proximate the piston head and an outside of the lumen, the blow-off pipe adapted to facilitate fluid flow from the proximal location to the outside to reduce pressure at the proximal location.

17. The apparatus according to claim 15, wherein the vent tube is adapted to be connected to a source of suction to actively facilitate fluid flow from the lumen from the distal location in the gastrointestinal tract.

18. The apparatus of claim 1, further comprising a piston head pressure sensor adapted to detect pressure in the piston head.

19. The apparatus of claim 18, further comprising a distal pressure sensor adapted to detect pressure distal to the piston head.

20. The system of claim 18, further comprising a proximal pressure sensor adapted to sense pressure proximal to the piston head.

21. The apparatus of claim 5, further comprising:

22. The apparatus of claim 1, further comprising:

an optical element coupled within the support body in a region proximate the distal portion and configured to provide an omnidirectional transverse viewing angle.

23. The apparatus of claim 22, further comprising:

an inflation element secured within the vicinity of the distal portion of the support body and adapted to increase the support body diameter in said vicinity to such an extent as to position the optical element at a distance from the wall of the body lumen sufficient to achieve omnidirectional focusing of the optical system.

24. The apparatus of claim 1, further comprising an auxiliary piston head coupled to the support body at a location proximal to the piston head.

25. The apparatus of claim 24, wherein the auxiliary piston head is configured to be inflated so as to form and maintain an auxiliary pressure seal with the wall of the gastrointestinal tract.

26. The apparatus of claim 24, wherein:

(a) at least one time while the support body is in the lumen, the piston head is in a state of having been at least partially deflated, while, at the same time, the auxiliary piston head has been inflated and advanced distally through the lumen in response to pressure from the fluid pressure source,

(b) at least one other time when the support body is in the lumen, the auxiliary piston head is in a state that has been at least partially deflated while the piston head has been inflated and advanced distally through the lumen in response to pressure from the fluid pressure source.

27. An apparatus according to claim 24, wherein the auxiliary piston head is axially fixed to the support body at a fixed distance from the piston head.

28. The apparatus of claim 24, wherein the support body comprises an auxiliary piston head channel in fluid communication with the auxiliary piston head and connectable to an auxiliary piston head fluid pressure source to inflate the auxiliary piston head.

29. The apparatus of claim 1, wherein the piston head is adapted to be proximally withdrawn through a lumen of a human body in response to pressure from the fluid pressure source.

30. The apparatus of claim 1, further comprising a hydrophilic substance disposed on an outer surface of the piston head.