HK1170791B - Needleless access port valves - Google Patents

Description

Needleless access port valve

Technical Field

The present invention relates to needleless access port valves, and more particularly to needleless access port valves having a movable piston for creating a fluid flow path between an inlet and an outlet of a valve housing. In certain embodiments, the piston incorporates differently configured slits to permit fluid flow between the piston and the interior surface of the housing.

Background

Needleless access port valves are widely used in the medical industry for accessing IV lines and/or the body of a patient or subject. Typically, a valve housing in combination with a movable internal plunger or piston is used to control fluid flow through the needle-free valve. The plunger or piston may be moved by a syringe or medical implement to open the inlet of the valve to access the internal cavity of the valve. When fluid is delivered through the valve, the fluid flow typically flows around the outside of the plunger or piston in a direction toward the outlet. After removal of the syringe or medical implement, the plunger or piston returns to its original position immediately, without or with the assistance of a biasing member such as a spring or diaphragm.

In some valves, when a syringe or medical implement pushes on a plunger or piston, the plunger or piston is pierced by an internal piercing device, such as a spike. The spike typically incorporates one or more fluid channels for fluid flow through the pierced piston and then through the fluid channels in the spike. In still other prior art valves, a self-flushing or positive flushing feature is incorporated to push residual fluid confined inside the internal cavity of the valve out of the outlet when the syringe or medical implement is removed.

While prior art needleless access port valves are viable options for their intended applications, there remains a need for alternative needleless access port valves.

Disclosure of Invention

The present invention may be implemented by providing a valve assembly comprising: a valve housing having an interior cavity, a bottom opening, and an inlet nozzle having an inlet opening and an interior wall surface along a central axis; a piston positioned inside the valve housing having a flange, a neck section, a body section, and a base; the piston further includes a slit having a first slit surface and a second slit surface, the slit extending radially across two opposing outer surface sections of the flange and longitudinally in a direction of the inlet opening toward the bottom opening and through at least a portion of the neck section below the flange, the first and second slit surfaces extending through at least a portion of the neck section below the flange, and the slit making an angle about the central axis.

The present invention may also be practiced by providing a valve assembly comprising: a piston positioned inside a valve housing, the piston comprising a flange, a neck section, a body section comprising an upper section and a lower section defining an interior cavity, an exterior wall surface, and a base; the valve housing including an inlet nozzle having an inlet opening, a body section defining an interior cavity having an interior wall surface, and a bottom opening; wherein the neck section of the piston comprises a slit formed in a helical configuration across the entire flange and through at least a portion of the neck section to the outer wall surface of the piston; the slit and the interior wall surface of the valve housing define a fluid space for fluid flow through the inlet nozzle and out of the bottom opening.

The invention further includes a method of making a piston for use in an access port valve, the method comprising: molding a piston comprising a neck section of reduced diameter compared to a body section defining an internal cavity; and cutting a slit in the neck section; wherein the cutting step comprises rotating a blade an angle about an axis of the piston while translating the blade a distance along the axis.

Aspects of the invention further include provisions for an actuator co-molded with the piston for opening the slit.

Still further aspects of the invention include the incorporation of internal indentations and/or ribs for forming fluid flow paths inside the interior cavity of the valve housing.

The present invention includes measures for incorporating an antimicrobial agent into at least one of a piston, a valve housing, and a nut fitting to control undesirable microbial growth. Exemplary agents include silver, gold, copper, and compounds thereof.

Yet another aspect of the present invention includes the provision for cutting a slit on the piston via a cutting process. Exemplary processes include thin blade cutting, cutting by laser, cutting by water jet cutting, and cutting with a combination blade and ultrasonic generator device.

These and other features and advantages of the present invention will become apparent, and likewise become better understood, with reference to the specification, claims and drawings.

Drawings

The drawings attached hereto include:

FIG. 1 is a semi-schematic cross-sectional side view of a valve piston provided in accordance with aspects of the present invention having an inlet actuator configured to open and close an upper section of the piston to form a fluid flow path;

FIG. 2 is a semi-schematic cross-sectional side view of the valve piston of FIG. 1 with the inlet actuator in an open position;

FIG. 3 is a semi-schematic perspective view of an actuator provided in accordance with aspects of the present invention;

FIG. 4 is a semi-schematic cross-sectional side view of an actuator mounted on a core pin used to form a piston;

FIG. 5 is a semi-schematic perspective view of the piston of FIG. 1 showing the actuator and various profiles in an open position and hidden lines as dashed-dotted lines;

FIG. 6 is a semi-schematic partial cross-sectional side view of the piston of FIG. 1 positioned inside a valve housing in a first closed position and having a partial view of a tip of a medical implement;

FIG. 7 is a semi-schematic partial cross-sectional side view of the valve of FIG. 6 with the piston advanced distally into the valve housing and the actuator in an open position;

FIG. 8 is a semi-schematic partial side view and partial cross-sectional view of a valve housing provided in accordance with aspects of the present invention;

FIG. 9 is a semi-schematic partial side view of another valve housing provided in accordance with aspects of the present invention;

FIG. 10 is a semi-schematic cross-sectional side view of an alternative valve piston provided in accordance with aspects of the present invention, the valve piston having an inlet actuator configured to open and close an upper section of the piston to form a fluid flow path;

FIG. 11 is a semi-schematic cross-sectional side view of the valve piston of FIG. 10 with the inlet actuator in an open position;

FIG. 12 is a semi-schematic perspective view of an alternative actuator provided in accordance with aspects of the present invention;

FIG. 13 is a semi-schematic side view of yet another valve piston provided in accordance with aspects of the present invention; the valve piston incorporates a slit at the neck section of the piston;

FIG. 14 is a semi-schematic cross-sectional side view of the piston of FIG. 13 taken along line 14-14;

FIG. 15 is a semi-schematic partial cross-sectional side view of a valve assembly provided in accordance with aspects of the present invention; the valve assembly includes the piston of FIG. 13 positioned inside a valve housing;

FIG. 16 is a semi-schematic partial cross-sectional side view of the valve assembly of FIG. 15 with the piston moved to a second position by a tip of a medical implement;

FIG. 17 is a semi-schematic side view of yet another valve piston provided in accordance with aspects of the present invention; the valve piston incorporates a slit at a neck section of the piston having a through bore;

FIG. 18 is a semi-schematic cross-sectional side view of the piston of FIG. 17 taken along line 18-18;

FIG. 19 is a semi-schematic cross-sectional side view of an alternative valve housing provided in accordance with aspects of the present invention, which incorporates a cross-bar at the lower neck section of the inlet nozzle;

FIG. 20 is a semi-schematic cross-sectional side view of the valve housing of FIG. 19 taken along line 20-20;

FIG. 21 is a semi-schematic partial perspective expanded view of the piston of FIG. 17 positioned inside a cavity of the valve housing of FIG. 19;

FIG. 22 is a semi-schematic partial cross-sectional partial side view of an alternative valve assembly provided in accordance with aspects of the present invention; the valve assembly includes the piston of FIG. 17 positioned inside the valve housing of FIG. 19 and wherein the tip of the medical implement is placed in contact with the top surface of the piston;

FIG. 22A is a semi-schematic partial mold cross-sectional partial side view of the valve assembly of FIG. 22 taken from a perspective rotated 90 degrees along the longitudinal axis of the valve housing;

FIG. 22B is a semi-schematic partial cross-sectional partial side view of the valve assembly of FIG. 22 with the piston moved to a second use position by the tip of the medical implement to open a flow path for fluid flow from between the inlet and the outlet of the valve assembly;

FIG. 23 is a semi-schematic cross-sectional side view of yet another alternative valve piston provided in accordance with aspects of the present invention;

FIG. 24 is a semi-schematic partial cross-sectional partial side view of yet another alternative valve assembly provided in accordance with aspects of the present invention; the valve assembly includes the piston of FIG. 23 positioned inside a valve housing having corresponding extensions for cooperating with a pair of cavities located on the piston;

FIG. 25 is a semi-schematic cross-sectional side view of yet another alternative valve piston provided in accordance with aspects of the present invention;

FIG. 26 is a semi-schematic cross-sectional side view of a nut assembly provided in accordance with aspects of the present invention for mating with a valve housing;

FIG. 27 is a cross-sectional side view of the nut assembly of FIG. 26 taken along line 27-27;

FIG. 28 is a semi-schematic partial cross-sectional partial side view of yet another alternative valve assembly provided in accordance with aspects of the present invention; the valve assembly includes the piston of FIG. 25 positioned inside a valve housing having the nut fitting of FIG. 26 coupled at a lower end of the valve housing;

FIG. 29 is a semi-schematic partial cross-sectional partial side view of the valve assembly of FIG. 28 with the piston moved to a second position by a tip of a medical implement;

FIG. 30 is a partial semi-schematic perspective view of a piston according to aspects of the present invention, and FIG. 30A is a partial perspective top view of the piston;

FIG. 31 is a cross-sectional side view of the piston of FIG. 33 taken along line 31-31;

FIG. 32 is a semi-schematic side view of the piston of FIG. 31 showing a spiral slit configuration for providing a fluid flow path;

FIG. 33 is a semi-schematic side view of the piston of FIG. 32 taken from a perspective rotated 180 degrees along the longitudinal axis of the piston;

FIG. 34 is a semi-schematic partial cross-sectional partial perspective view of the piston of FIG. 31 positioned inside an invisible valve housing; the valve housing may include any of the valve housings shown in fig. 6 and 9 and 37;

FIG. 35 is a semi-schematic partial cross-sectional partial perspective view of the piston of FIG. 34 moved toward a second position by a tip of a medical implement;

FIG. 36 is a semi-schematic partial cross-sectional partial perspective view of the piston of FIG. 34 moved to a second position by a tip of a medical implement;

FIG. 37 is a simplified partial cross-sectional view of a valve incorporating the piston of FIG. 34 according to another embodiment of the present invention;

FIG. 38 is a simplified partial cross-sectional view of a Y-site valve incorporating the piston of FIG. 34 according to another embodiment of the present invention; and is

Fig. 39A is a semi-schematic general depiction of an ultrasonic generator equipped with a cutting blade, and fig. 39B is a simplified general depiction of a robotic cutter equipped with a cutting blade for cutting a crack or slit in a piston.

Detailed Description

The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of needleless access port valves or check valves (hereinafter "valves") provided in accordance with aspects of the present invention and is not intended to represent the only forms in which the present invention may be constructed or utilized. The description sets forth the features and steps for constructing and using the valve of the present invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and structures may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention. As indicated elsewhere herein, like element numbers are intended to indicate like or similar elements or features.

Referring now to FIG. 1, there is shown a semi-schematic cross-sectional side view of a valve piston or piston provided in accordance with aspects of the present invention, the valve piston or piston being generally designated 10. As discussed further below, the piston 10 is configured to regulate flow through a valve housing by: expand and seal against the valve housing to inhibit flow between the inlet and outlet of the housing, and compress or deform to permit flow therebetween. In one exemplary embodiment, the piston 10 includes a flexible, resilient body 12, the flexible, resilient body 12 including: a first end 14 including a base or first flange 16; and a second end 18 including a second flange 20. For purposes of discussion only, the first end 14 will be identified as the base end and the second end 18 will be identified as the adjustment end.

As provided in accordance with aspects of the present invention, the first or base flange 16 has an outer diameter that is greater than the diameter of the body section 17 of the piston body 12. The upper surface 22, lower surface 24, and recessed lower surface 26 of the flange 16 are configured to be compressed intermediate a nut fitting and a flange seat located on a valve housing, as described in U.S. Pat. No. 6,871,838 (herein "the' 838 patent"), the contents of which are expressly incorporated herein by reference.

In one exemplary embodiment, the body section 17 of the piston body 12 includes a generally straight cylindrical wall structure that extends between the base flange 16 and the first shoulder 28 with an acceptable slight taper (e.g., draft angle). A lower neck section 30 extends proximally of the first shoulder 28, having a diameter less than the diameter of the body section 17. The reduced section 32 extends proximally of the lower neck section 30 (or an enlarged section if viewed from a proximal direction to a distal direction) into an upper neck section 34 connected to the upper flange 20. When the piston 10 is positioned inside a valve housing (not shown), the first shoulder 28 and the second flange 20 engage corresponding surfaces inside the interior cavity of the housing to restrict flow around the exterior surface of the piston around the flow space defined by the interior surface of the valve housing and the exterior surface of the piston, as discussed further below.

The piston body 12 defines an interior cavity 36 having a lower chamber 38 and an upper chamber 40. In one exemplary embodiment, the interior cavity 36 is in fluid communication with the ambient atmosphere. Thus, when the piston body 12 is depressed and released, air moves in and out of the interior cavity 36 of the piston body 12.

In one exemplary embodiment, the piston 10 is made of a flexible elastomeric material, with silicone being more preferred. Alternatively, the piston may be made of a thermoplastic elastomer (TPE) type, such as the Copolyamide (COPA) family of thermoplastic elastomers. In an exemplary embodiment, COPA is PEBAX having a commercial trade nameThe copolycondensation amide thermoplastic elastomer of (4). However, other TPEs may also be used, including Thermoplastic Polyurethanes (TPUs), styrenic thermoplastic elastomers, Thermoplastic Polyolefins (TPOs), Copolyesters (COPEs), and thermoplastic vulcanizate elastomers (TPVs). Optionally, the TPE may be crosslinked chemically or by irradiation to modify its properties. Still alternatively, the piston may be made of a self-lubricating silicone material, as disclosed in the' 838 patent. The piston 10 is preferably self-resilient in that it flexes when compressed and when a load or force applied to the piston is removedReverting to substantially its original shape without the aid of a spring. However, as in the' 838 patent, previously incorporated by reference, a spring may be incorporated to facilitate recovery of the piston upon removal of the applied force. When an external biasing member is used to assist the piston in returning from the second position to the less compressed first position, the piston body may be made of a flexible but not necessarily resilient material. The less compressed state is measured relative to the body section, which is under less axial compression when in the first position than in the second position.

In one exemplary embodiment, an antimicrobial composition for controlling or resisting bacterial contamination (e.g., reducing the amount of biofilm formation) inside a valve is provided. The use of antimicrobial compositions in medical devices is well known in the art and is described, for example, in U.S. patent nos. 4,603,152 to Laurin (Laurin) et al, 5,049,139 to Gilchrist (Gilchrist) et al, and 5,782,808 to forden (Folden) et al. The use of antimicrobial compositions is also disclosed in publications 2002/0133124a1 and 2003/0199835a1, both issued to Leinsing et al. The contents of these patents and publications are expressly incorporated herein by reference as if fully set forth. In one particular aspect of the invention, the silver zirconium phosphate is formulated into the molding material used to mold the piston 10, i.e., added to the TPE, silicone, or self-lubricating silicone material. The silver compound may vary from about 4% to about 10% by weight of the blended injection, with a preferred range between about 6% and about 8%. Alternatively or in addition thereto, an antimicrobial composition is also blended in the material used to mold the valve housing and/or nut fitting discussed further below. Other antimicrobial agents that may be used with the components of the present invention include: silver, gold, platinum, copper and zinc. Antimicrobial metal compounds for use herein include oxides and salts, preferably of silver and also gold, such as: silver acetate, silver benzoate, silver carbonate, silver citrate, silver chloride, silver iodide, silver nitrate, silver oxide, silver sulfadiazine, silver sulfate, gold chloride and gold oxide. Platinum compounds such as chloroplatinic acid or salts thereof (e.g., sodium and calcium chloroplatinate) may also be used. Also, compounds of copper and zinc may be used, for example: oxides and salts of copper and zinc, such as those indicated above for silver. A single physiological antimicrobial metal compound or a combination of several physiological antimicrobial metal compounds may be used. Still alternatively, a thin antimicrobial agent may be deposited over the wall surfaces of various valve assemblies, as disclosed in the' 808 Folderon patent.

In one exemplary embodiment, the piston has the following physical properties: a specific gravity of about 1.15, wherein a range of about 1.1 to about 1.2 is acceptable; a 50 Shore A hardness, with an acceptable range of about 40 to about 60 hardness; a minimum tensile strength of at least 600psi, with a minimum of about 800psi being more preferred; an elongation rating of about 275% minimum, with about 350% minimum being more preferred; and a tear strength of about 100ppi (pounds per inch) minimum, with 125ppi being more preferred. These values are provided merely as exemplary properties of certain piston embodiments and may vary for certain applications and material selections.

In one exemplary embodiment, an inlet actuator 42 is incorporated on the upper neck section 34 of the piston body 12 for opening and closing a fluid path formed through the second flange 20 and at least a portion of the upper neck section 34. The inlet actuator 42 may be made of a rigid or semi-rigid thermoplastic, such as glass-filled nylon, and molded to the piston body 12 using an overmolding process. The inlet actuator 42 has a generally V-shaped configuration and has an inner side surface 46 and an outer side surface 48 (FIG. 2). Two opposing inlet plates 44 are formed on an inside surface 46 of the inlet actuator 42. A slit 50 is formed between the two inlet plates. In one exemplary embodiment, the two inlet plates 44 are made of the same material as the piston body 12 and are overmolded to and integral with the inlet actuator 42. The inlet plate 44, which is flexible, forms a fluid-tight seal along at least a portion of the slit 50 when the two plates are in contact with each other (this corresponds to the piston first position when positioned inside the valve housing) when the piston 10 is in a less compressed state as shown in fig. 1. Preferably, the slit 50 is aligned along the longitudinal axis of the piston. However, the slit may extend transverse to the longitudinal axis of the piston without departing from the spirit and scope of the present invention.

FIG. 2 is a semi-schematic cross-sectional side view of the piston 10 of FIG. 1 shown with the inlet actuator 42 in an open configuration. In one exemplary embodiment, the inlet actuator 42 naturally biases to the open position shown in FIG. 2, and the slits 50 separate to form gaps when no force is applied to the outside surface 48 of the actuator 42. In one exemplary embodiment, a protrusion 52 on the outside surface 48 of the inlet actuator and a corresponding groove 52 on the interior surface of the upper neck section 34 are incorporated to enhance the engagement between the inlet actuator and the piston body. However, multiple grooves and multiple projections between the inlet actuator and the piston body, an opposing groove and projection configuration, or a combination of both projections and grooves on the inlet actuator and the piston body may be incorporated without departing from the spirit and scope of the present invention.

FIG. 3 is a semi-schematic perspective view of an inlet actuator 42 provided in accordance with aspects of the present invention. In one exemplary embodiment, the inlet actuator 42 includes an arcuate base 56 and two extension members 58 forming a V-shaped configuration having a more rounded apex at the arcuate base 56 than a typical V. The generally V-shaped structure causes the two extensions 48 to diverge such that the two inner side surfaces 46 generally do not touch or contact each other, i.e., are biased away from each other.

FIG. 4 is a semi-schematic cross-sectional side view of the inlet actuator 42 mounted on the core pin 60. Core pin 60 forms the contour of the interior cavity of piston body 12 and is configured to work in conjunction with mold and inlet actuator 42 to form piston 10. The core pin 60 includes a receptacle 62 for receiving and holding the inlet actuator 42 in a slightly compressed state with the ends 64 of the two extensions 58 moving closer to each other than when in the normal expanded state shown in FIG. 3.

FIG. 5 is a semi-schematic perspective view of the piston 10 of FIG. 2 shown with dot-dashed lines representing hidden lines. When no inwardly acting force is applied to the two extensions 58 of the inlet actuator 42 (i.e., when the extensions 58 are unconstrained), they expand open to enlarge the fracture 50 and form the gap 66. Thus, if fluid is placed at the end 64 of the extension 58, it will flow in-between and out through the side gaps 66 of the fracture 50.

FIG. 6 is a partial semi-schematic side view of the piston 10 of FIG. 1 shown with the tip 69 of a medical implement (e.g., a syringe or tubing adapter) positioned inside the valve housing 68 in a closed or first position. The valve housing 68 includes an inlet nozzle 70 defining an inlet opening 72. In one exemplary embodiment, the inlet comprises a Luer (Luer) inlet that includes external threads 74 but may not have threads, i.e., a Luer slip lock. The interior surface 76 of the inlet nozzle 70 defines a circumference sized sufficiently smaller than the diameter of the second flange 20 to compress the second flange from the position shown in fig. 2 into the closed position shown in fig. 1. In one exemplary embodiment, the internal ID of the inlet nozzle is about 0.5 mils to about 8 mils smaller than the normal closed diameter of the second flange 20, with a range of about 0.1 mils to about 3 mils being more preferred. This relative dimension between the inner diameter of the inlet nozzle and the normal closed diameter of the second flange 20 creates a seal at the inlet 72 for terminating fluid communication between the inlet 72 and the outlet (not shown) of the valve assembly 78. While FIG. 6 shows the reduced section 32 between the lower neck section 30 and the upper neck section 34 of the piston 10 spaced from the shoulder 70 in the interior cavity of the inlet nozzle 70, in one exemplary embodiment, the two contact each other to provide a second sealing point.

FIG. 7 is a semi-schematic partial cross-sectional side view of the valve assembly 78 of FIG. 6 in a second or open position with the tip 69 of the medical implement inserted into the inlet lumen of the inlet nozzle 70. The tip 69 applies downward pressure to both the inlet actuator 42 and the piston body 12 and pushes both distally into the interior cavity of the valve housing 68. As discussed in the' 838 patent, which is previously incorporated by reference herein, the piston body 12 collapses into random folds under the pressure of the tip 69 as the piston 10 moves to its second position. In one exemplary embodiment, as the piston moves to its second position, the collapsing piston body changes the space occupied by the piston a sufficient amount to create a negative bolus effect or negative flush represented by a small amount of fluid entering the internal cavity of the valve.

The inlet actuator 42 moves to an enlarged lower neck section 82 of the valve housing 69 that defines an inner circumference 84 that is greater than the inner circumference 76 of the upper inlet nozzle section 70. The larger lower neck section 82 provides sufficient space to enable the inlet actuator 42 to expand, which separates the slits 50 to form a flow path or gap 66 for fluid flow from or toward the medical implement. Assuming that fluid is delivered by the medical implement, the fluid flow will flow out of the tip 69, through the gap 66 formed at the slit 50, and out through both sides of the slit. The fluid then travels in the space between the interior wall surface of the valve housing 68 and the exterior surface of the piston 10 and out the valve outlet (not shown). Upon removal of the tip 69 from the inlet nozzle 70, the piston 10 expands due to the resilient nature of the material used to form the piston 10, which returns to the position shown in fig. 6. In one exemplary embodiment, a positive bolus effect is created when the piston 10 expands to its first position, which is characterized by a small amount of fluid being pushed out of the outlet from the internal cavity of the valve.

FIG. 8 is a semi-schematic partial cut-away side view of an exemplary valve housing 68 provided in accordance with aspects of the present invention shown without a piston. Referring to fig. 8, as well as fig. 7, the interior cavity 86 has a further enlarged interior circumference 88 defined by a body section 90 of the valve housing 68. The lower larger inner circumference 88 includes a lower generally circular or curved shoulder 92. In one exemplary embodiment, a curved shoulder 92 is provided for mating contact with the first shoulder 28 on the piston body 12 to provide another sealing point.

In one exemplary embodiment, the inner circumference 88 of the body section 90 has a smooth surface. The inner circumference 88 defines a main inner diameter 89 that extends over a majority of the body section to have a generally constant diameter, which in one exemplary embodiment is generally constant from just distal of the lower shoulder section 92 to about the interface of the body section 90 and the skirt 94. In one exemplary embodiment, the main inner diameter 89 is sized sufficiently larger than the diameter of the body section 17 of the piston 10 (fig. 1) such that fluid flow delivered through the inlet opening 72 of the valve housing 68 or from the outlet of the valve housing toward the inlet opening for sampling through the valve has sufficient fluid flow space to flow out of the valve outlet 100.

Externally, the valve housing 68 incorporates a plurality of ribs 93, which in one exemplary embodiment includes four equally spaced ribs. A downwardly extending skirt 94 depends from the body section 90 and terminates in a lower opening 96 for receiving a nut fitting 98. As discussed in the' 838 patent, the nut fitting 98 includes an outlet port 100 for outputting fluid delivered through the inlet opening 72 and a threaded collar 102 for threaded engagement with a second medical implement (not shown), which may be a tubing adaptor, a catheter, or the like. The nut fitting 98 may be ultrasonically welded or alternatively glued to the skirt 94 by welding or gluing a flange 104 on the nut fitting 98 to an end edge of the skirt 94.

FIG. 9 is a semi-schematic cross-sectional side view of an alternative valve housing 106 provided in accordance with aspects of the present invention. In one exemplary embodiment, the valve housing 106 includes an inlet nozzle 108 defining the inlet opening 72, a main body section 112, and a skirt 114 depending therefrom having an end edge 116 defining a lower housing opening 118.

Internally, the valve housing 106 includes an upper inlet section or upper neck section 120, a tapered section or lower neck section 122, a main inner body section 124, and an inner skirt section 126. In one exemplary embodiment, the inner body section 124 includes a plurality of raised ribs 128 that project above the inner wall surface of the inner body section 124 and a plurality of indentations 130 that are recessed below the inner wall surface of the inner body section. The raised ribs 128 and the indentations 130 provide a flow path or channel for fluid flow from the inlet to the outlet of the valve intermediate the space defined by the interior wall surface of the valve housing and the exterior surface of the piston.

In one exemplary embodiment, a plurality of lower indentations 132 are incorporated in the interior wall surface 134 of the skirt section 114. The lower indent 132 is preferably aligned with the upper indent 130 such that fluid flow through the upper indent will flow to the lower indent on its way towards the outlet. In one exemplary embodiment, eight raised ribs 128, eight upper indentations 130, and eight lower indentations 132 are incorporated. The ribs and indentations are preferably equally spaced from each other. Also shown, a locator 117 is formed on the skirt section for locating the nut fitting. In one exemplary embodiment, three spaced-apart locators are incorporated.

Fig. 10 is a semi-schematic cross-sectional side view of an alternative piston 136 provided in accordance with aspects of the present invention. The piston 136 is configured to work with a valve housing, such as the valve housing shown in fig. 6-9, to regulate fluid flow from between the inlet and outlet of the valve housing or flow in the reverse direction. In one exemplary embodiment, the piston 136 includes a piston body 138 defining an internal cavity 142 and an inlet actuator 140. The piston body 138 is similar to that disclosed with reference to fig. 1, 2, and 5, with a few exceptions. In the present embodiment, the upper neck section 34, the lower neck section 30, and a portion of the body section 17 are formed solid from the same material as the piston wall, which is collectively referred to herein as the upper piston core 144. The body section 17 defining the cavity 142 is referred to herein as the flexible and resilient piston base 146. Like the inlet actuator 42 of the embodiment of fig. 1, the inlet actuator 140 in this embodiment includes a protrusion 148 configured to be exposed through the upper neck section 34.

When the piston 136 is installed inside a valve housing and compressed during operation, the pliable and resilient piston base 146 is configured to buckle and twist in a random manner to accommodate the tip of a medical implement. In one exemplary embodiment, the pliable and resilient piston base 146 is configured to recoil without the assistance of a spring or other independent biasing member upon removal of the medical implement. By selecting an elastomer or TPE with sufficient resilience, wall thickness, and stiffness, the pliable piston base 146 can exhibit sufficient spring characteristics that will allow it to spring back without a separate spring. However, as is readily apparent to those skilled in the art, a coil spring may be placed inside the internal cavity 142 to facilitate piston recovery, as discussed in the' 838 patent.

FIG. 11 is a cross-sectional side view of the piston 136 of FIG. 10 shown with the inlet actuator 140 in its normal state outside the valve housing. As clearly shown, the two extensions 58 are spaced apart from each other, which opens a gap for fluid flow at the seam 50, as previously discussed.

FIG. 12 is a semi-schematic perspective view of the inlet actuator of FIGS. 10 and 11. Each of the two extensions 58 includes an extension leg 150. In one exemplary embodiment, the piston body 138 is molded over the inlet actuator 140 by: the inlet actuator is first placed in a mold cavity, the core pin is placed therein, the sheet is placed between the two extensions, and the mold is then injection molded with an elastomer or TPE. After the injection process, the piston is removed and a crack 50 is formed in the overmolding process.

FIG. 13 is a semi-schematic side view of yet another embodiment of a piston 152 provided in accordance with aspects of the present invention. In one exemplary embodiment, the piston 152 includes a lower flange 16, a body section 154, and a neck section 156 that includes an upper flange 158. A slit 160 is incorporated approximately along the center of the neck section 156 to define two piston neck extensions 157. The slit 160 extends between an upper top surface 162 of the piston and a shoulder 164 at an upper edge of the body section 154. The slit 160 defines a slit having a plane that can open or close to form a gap depending on the position of the piston 152 when inside the valve housing. Preferably, the slit 160 is aligned along the longitudinal axis of the piston. However, the slit 160 may extend transverse to the longitudinal axis of the piston without departing from the spirit and scope of the present invention.

FIG. 14 is a cross-sectional side view of the piston of FIG. 13 taken along line 14-14. In one exemplary embodiment, the neck section 156 is molded as a solid structure with the slit 160 formed through a cutting process after the molding step. Exemplary cutting processes include cutting the neck section with a thin blade, by laser cutting, or by water jet cutting. Referring to FIG. 39, in one embodiment of the invention, a thin blade 290, about 0.015 inches to about 0.03 inches thick, having a sharp edge, preferably a dissimilar metal such as titanium, is used to cut the slit 160. The blade is mounted to a coupler or shaft 292 that is connected to a prior art ultrasonic generator 294 that preferably has an operating range of about 20kHz to about 40 kHz. An exemplary generator includes the Branson 2000aed model. The piston 152 is then placed in a fixture 296, such as a pedestal or roller, with the neck section directly adjacent the blade 290. The ultrasonic generator 294 is then energized while simultaneously moving the blade coaxially into the piston with the piston held vertical or perpendicular to the piston centerline with the piston held horizontal. Once the slit 160 has been made, the blade is de-energized and withdrawn away from the piston. Alternatively, the vibrating blade may be held stationary and a piston mounted on a base or drum 296 moved toward the vibrating blade to form the slit.

A solid upper body section 166 extends distally of neck section 156 with a stop pin 168 extending distally thereof into interior cavity 142 of body section 154. The stop pin 168 is configured to limit over-insertion of the medical implement by providing a physical stop and limit the amount of inward collapse of the piston wall into the internal cavity 142 when cranked by the medical implement from the top and the nut fitting from below.

FIG. 15 is a partial cross-sectional side view of the piston 152 mounted inside the valve housing 68 to form a valve assembly 170. The piston 152 is shown in a first or closed position with the upper flange 158 compressed against the interior wall surface of the inlet nozzle 70, which functions to seal the valve 170 and close fluid communication between the inlet opening 72 and an outlet (not shown). The piston shoulder 164 also abuts the lower shoulder 92 of the valve housing 68 to provide another sealing point.

FIG. 16 is a semi-schematic partial cross-sectional side view of the valve assembly 170 of FIG. 15 pushed by the tip 69 of the medical implement to a second or use position. The tip 69 pushes the upper top surface 162 of the piston 152 into the interior section 84 of the enlarged lower section 82 of the inlet nozzle 70. Due to the larger interior space at the enlarged lower section 82, the two piston neck extensions 157 are forced apart (which can be described as a kink effect caused by the medical implement and stop pin 168) so as to form the gap 66 at the split 50. At this point, the fluid delivered by the medical implement will flow out of the tip 69, through the slit 50, and then around the outside surface of the piston 152 and the interior surface of the valve housing 68. Conversely, if sampling is to be performed, flow will flow intermediate the space defined by the interior surface of the valve housing and the exterior surface of the piston, then through the slit 50 and into via the tip 69.

The piston 152 automatically moves from the second position (fig. 16) to the first position (fig. 15) upon removal of the tip 69 from the inlet nozzle 70. The piston body section 154 automatically recovers due to its inherent rebound characteristics. Alternatively, as previously discussed, a coil spring may be used to facilitate recovery.

Fig. 17 is a semi-schematic cross-sectional side view of yet another piston 172 provided in accordance with aspects of the present invention. In one exemplary embodiment, the alternative piston 172 is similar to the piston 152 disclosed in fig. 13 and 14, with a few exceptions. For example, the piston 172 incorporates: a slit 160 defining a slit and separating the neck section 156 into two piston neck extensions 157; and a stop pin 168. In the present embodiment, a through-hole 174 having a polygonal cross-section is formed along at least a portion of the through-hole. In a preferred embodiment, the through-hole 174 is a hexagonal polygon oriented such that two vertices 176 are longitudinally aligned in the same direction as the vertical slit 160. The through-holes 174 are formed such that half of the through-holes are formed on one piston neck extension 157 and the other half on the other piston neck extension.

Reference is now made to fig. 18, which is a cross-sectional side view of the piston 172 of fig. 17, taken along line 18-18. In one exemplary embodiment, the through-hole 174 is formed by molding a tapered upper surface 178 and a molded tapered lower surface 180 that are spaced apart from each other by a side surface 182. The tapered upper surface 178 is configured to abut a cross rib located inside the valve housing that acts to impart a pair of force components to the tapered surface that push the piston neck extension 157 outward, as discussed further below. The lower tapered surface region 180 has a similar profile as the lower surface of the cross-rib, as discussed further below, and is configured to abut against the lower surface when in the piston first position.

In one exemplary embodiment, upper tapered surface 178 has a length that is relatively shorter than the length of lower tapered surface 180. This relative dimension forms an exposed via region 185 at each end thereof. As shown with reference to fig. 21, the two exposed ends 185 are configured to receive respective ends of a cross-rib located inside the valve housing. However, as is readily apparent to those skilled in the art, the two exposed ends 185 (fig. 21) may differ in shape, size, and contour, depending on the shape, size, and contour incorporated for the cross-rib, which may vary depending on the designer's choice.

FIG. 19 is a semi-schematic cross-sectional side view of a valve housing 184 provided in accordance with aspects of the present invention. The valve housing 184 is similar to the valve housing discussed with reference to the valve housing of fig. 8 and 9 with a few exceptions. Among the differences, a cross-bar 186 is incorporated into the interior cavity of the enlarged lower section 82 of the inlet nozzle 70. In one exemplary embodiment, the cross-bar 186 includes a generally circular upper middle section 188 and a V-shaped bottom section 190 that includes an apex. The cross-bar is preferably integrally molded with the valve housing 184.

In one exemplary embodiment, the inner circumference 88 of the body section 90 includes a flat or smooth inner wall surface. However, raised ribs or flow indentations or both may be incorporated without departing from the spirit and scope of the present invention. In one exemplary embodiment, a plurality of lower indentations 132 are formed on the skirt section 94 of the valve housing.

FIG. 20 is a cross-sectional side view of the valve housing 184 of FIG. 20 taken along line 20-20. The cross-bar 186 has a circular upper middle section 188 as previously discussed and two angled ends 190 corresponding to the angled ends 192 located on the through-hole 174 of the piston 172. As will be readily apparent to those skilled in the art, the angled ends 190, 192 on the valve housing and piston, respectively, may be modified or eliminated without departing from the spirit and scope of the present invention, such as having the circular middle section 188 extend the entire length of the cross-bar. Still alternatively, a cross-bar having a single distinct upper apex, different curvatures, or multiple apexes may be incorporated.

FIG. 21 is a semi-schematic partial perspective cross-sectional view of the piston 172 of FIG. 18 partially positioned inside the valve housing 184 of FIG. 20. The piston 172 is configured to be inserted into the interior cavity 86 of the valve housing 184 by inserting the neck section 156 through the end opening 96 of the valve housing 184 and aligning the slit 160 with the cross-bar 186. The piston is then pushed proximally until the cross-bar is seated inside the through-hole 174. Once seated, the two inclined ends 190 of the crossbar rest inside the two exposed via regions 185. In one exemplary embodiment, a rod (not shown) is used to push the piston 172 inside the housing. The rod may be inserted through the open end 194 (fig. 17) of the piston and pushed against the stop pin 168.

FIG. 22 is a partial cross-sectional side view of a valve assembly 196 including the piston 172, the valve housing 184, and the nut fitting 98. The piston 172 is shown in a first or closed position with the upper flange 158 compressed against the interior surface 76 of the inlet nozzle 70 to both squeeze the two piston neck sections 157 together and terminate fluid flow from between the inlet opening 72 and the outlet port 100. A second seal is provided by the abutment of the shoulder 164 of the piston 172 against the lower shoulder 92 in the interior cavity 86 of the valve housing.

Fig. 22A is a partial cutaway side view of the valve assembly 196 of fig. 22, viewed from an orthogonal viewing plane.

Fig. 22B is a partial cross-sectional side view of the valve assembly 196 of fig. 22 and 22A in a second or use position. The tip 69 of the medical implement extends into the bore of the inlet nozzle 70 to compress the piston 172. As previously discussed, the force imparted by the tip causes the body section 154 (fig. 17) of the piston to buckle and twist into random folds. At the same time, a force is applied to the slit 160 on the cross bar 186, which then separates the slit 160 to expand the gap 66. The flow F delivered by the medical implement flows through the tip 69 and through the gap 66 formed at the split 50 before flowing out through both sides of the split and over the outer surface of the piston 172 toward the outlet 100. After delivery of the fluid via the medical implement, the tip 69 is removed from the inlet nozzle 70, which simultaneously removes the force acting on the top surface of the piston. This allows the piston 172 to return to its less compressed state (shown in fig. 22 and 22A).

As previously discussed, the piston 172 may be self-resilient and move from the second position to the first position without the assistance of a spring or a separate biasing member. However, a spring or separate biasing member may be placed inside the interior cavity 142 of the piston 172 to facilitate the piston returning from the second position toward the first position.

Fig. 23 is a semi-schematic cross-sectional side view of yet another piston 198 provided in accordance with aspects of the present invention. The present piston 198 embodiment shares a great deal of similarity with the piston 172 shown in fig. 17, 18, 20 and 22. However, although the piston 172 shown in fig. 17, 18, 20 and 22 incorporates a through-hole 174, the present piston 198 embodiment incorporates a dividing wall 202 at the through-hole to define two cavities 200. The two upper ends 204 of the two cavities 200 have also been modified to terminate in simple rounded corners. In one exemplary embodiment, the dividing wall 202 includes two tapered wall surfaces 206 that extend outward as the wall spans from a proximal position to a distal position. Each cavity 200 includes a tapered upper surface 178 and a tapered lower surface 180, similar to the through-holes 174 disclosed with reference to fig. 18.

FIG. 24 is a partial cutaway side view of a valve assembly 208 provided in accordance with aspects of the present invention, including the piston 198 shown in FIG. 23 mounted inside a valve housing 210. In one exemplary embodiment, the valve housing 210 is similar to the valve housing discussed above with reference to fig. 19 and 20, with a few exceptions. In this embodiment, the internal cavity of the housing includes two rib extensions 212 instead of a continuous cross-bar 186 at the junction between the inlet nozzle 70 and the main body section 90. The two rib extensions 212 are sized to protrude into the two cavities 200 (fig. 23) and the two cavities are sized to accommodate the two rib extensions.

In use, the tip 69 of the medical implement is inserted into the lumen defined by the inlet nozzle 70, which then applies a force to the piston 198. The downward force on the piston 198 pushes the two cavities 200 against the two rib extensions 212, which then act on the tapered upper surfaces 178 of the two cavities to split the neck section 156 along the slit 160 to open a gap at the slit. The gap provides a fluid flow path for fluid flow between the inlet opening 72 and the outlet 110.

After injection and after removal of the tip 69 from the inlet nozzle, the piston 70 is restored to its less compressed state by moving from the second position to the first position. As previously described, a spring or separate resilient member may optionally be used with the piston 198 to facilitate recovery after removal of the tip 69.

FIG. 25 is a semi-schematic cross-sectional side view of yet another alternative piston 214 provided in accordance with aspects of the present invention. In one exemplary embodiment, as with the other previously discussed pistons, the piston 214 includes a slit 160 separating the neck section 156 into two piston neck extensions 157. The piston 214 also includes a body section 154 and a lower flange 16. The body section 154 defines an internal cavity 142 that includes a top wall surface 216 and a spike bore 218. Spike bore 218 extends proximally from the top wall surface through upper body section 166 and a portion of lower neck section 30.

In a preferred embodiment, the spike bore 218 terminates in a tip 220, wherein the tip of the tip communicates with the slit 160 when the slit 160 is open. In one exemplary embodiment, the bore 218 comprises a single diameter cylindrical bore. Preferably, however, one or more reduced neck sections 222 are incorporated in the bore 218 to act as sealing rings around the activation pin, as discussed further below.

Fig. 26 is a semi-schematic cross-sectional side view of a nut fitting 224 provided in accordance with aspects of the present invention. In one exemplary embodiment, the nut fitting 224 is similar to the nut fitting disclosed in the' 838 patent, except for the central projection 226, which has an elongated activation pin 228 having a rounded tip 230. Other features of the nut fitting 224 include a circular channel 232, a raised floor 234, and a seal seat 236 including an optional protrusion 238 similar to a raised planar flange. Further, distally, the nut fitting 224 includes two spaced apart liquid passages 240, a skirt section 246 including one or more positioning members 242, a flange 244, and a discharge nozzle 248 including a lumen 250.

Fig. 27 is a cross-sectional side view of the nut fitting 224 of fig. 26 taken from line 27-27. A pair of exhaust ports 252 are incorporated for venting air trapped inside the internal cavity 142 of the piston 214 when the piston 214 is compressed by the tip of the medical implement, as discussed in the' 838 patent. In one exemplary embodiment, the two exhaust ports 252 are spaced 180 degrees apart from each other and are each located intermediate two liquid passages 240, which are also spaced 180 degrees apart from each other.

FIG. 28 is a semi-schematic partial cut-away side view of a valve assembly 254 provided in accordance with aspects of the present invention, including the piston 214 shown in FIG. 25 disposed in the valve housing 184, with the nut fitting 224 of FIGS. 26 and 27 secured to the lower opening 96 of the valve housing 68. In the piston first position shown, the upper flange 158 is sealed against the interior surface of the inlet nozzle and the piston shoulder 164 is sealed against the lower shoulder 92 on the housing to terminate fluid communication between the inlet 72 and the outlet 100. The two piston neck extensions 157 are squeezed together to close the gap that would otherwise form at the slit 160.

An elongated activation pin 228 is disposed in the spike bore 218 of the piston with a rounded tip 230 positioned adjacent the distal most point of the slit 160. The bore 218 is preferably sized with a neutral, i.e., no net interference fit or a somewhat loose fit, of about 0.5 mils to about 3 mils total clearance around the pin 228.

FIG. 29 is a semi-schematic partial cross-sectional side view of the valve assembly 254 of FIG. 28 in a second or use position with the piston in a more compressed state. Moving the piston to the use position by: the tip 69 of the medical implement is inserted into the inlet nozzle 70 of the valve housing 184 and causes the piston to collapse at the body section 154 (fig. 25), which simultaneously forces the bore 218 to move distally down the elongated activation pin 228 and causes the pin to move through the slit 160 to open the gap. Preferably, the upper top surface 162 of the piston is moved distally sufficiently to the enlarged lower section 82 of the valve housing 184 where sufficient circumferential space is provided for separating the two piston neck sections 157. Fluid delivered from the medical implement through the valve 254 at this time will flow down the tip 69, through the gap 66 and out to the side of the gap into the space between the exterior surface of the piston and the interior wall surface of the valve housing 184, as previously discussed.

To facilitate recovery of the piston 214 from the second position shown to the first position upon removal of the medical implement from the inlet opening 72, the piston 214 is sufficiently resilient to recover upon itself and/or a resilient member is used to bias the piston to its first position, as previously discussed. In this embodiment, friction between the activation pin 228 and the wall surfaces of the two piston neck extensions 157 at the slit 160 should be kept to a minimum. In one exemplary embodiment, the residual fluid delivered to the valve acts as a lubricant to minimize friction. However, as the two piston neck extensions 157 deflect, a plurality of voids or uneven wall surfaces 256 are formed adjacent to the activation pin 228 to reduce friction between the activation pin and the wall surfaces of the two piston neck extensions 157.

FIG. 30 is a partial semi-schematic perspective view of a piston 258 in accordance with aspects of the present invention. FIG. 31 is a cross-sectional side view of the piston of FIG. 33 taken along line 31-31. In one exemplary embodiment, the piston 258 includes an upper flange 158, a neck section 156 including the upper neck 34, the lower neck 30, and the piston body 136. The piston body 136 and the flexible and resilient piston base 146 and base flange 16 define an interior cavity 142. The piston 258 is configured to be used with a valve housing 302, such as the valve housing shown in fig. 37, to operate as a needle-free injection port valve.

Referring now to fig. 33, with continued reference to fig. 30 and 31, a piston 258 in accordance with aspects of the present invention incorporates a slit 260 formed into a helically twisted configuration for providing a fluid path through the neck section 156 when used in combination with the valve housing 302. In one embodiment, a slit 260 is formed in the upper or proximal end of the lower neck 30. In one exemplary embodiment, the slit 260 includes an upper slit section 262 and two lower slit sections 264. Each of the lower slit sections 264 extend in opposite directions relative to the upper slit section 262 as if wrapped at least partially around the circumference of the neck section 156 in opposite directions in a twisted manner. The cutting edge extends to the outer surface of the neck section, as shown in fig. 30A. As discussed further below, when the piston is compressed, the slit 260 is forced open to provide clearance for fluid flow through the upper neck 34 of the piston. Accordingly, the pistons provided herein are understood to include a solid upper piston section having a helical cut that includes two opposing leading cutting edges extending away from each other. Another aspect of the invention is a piston that includes a slit formed across the entire upper neck section 34 such that the upper flange 158 is continuously cut from one outer edge to the other, as shown in fig. 30. Note that although a gap is shown at the slit 260, due to the elasticity of the piston and the wall thickness of the cutting blade, both sections may touch and only a single line may be seen.

Referring now to fig. 32 with continued reference to fig. 33, in one embodiment, the upper and lower slit sections 262, 264 are formed post-mold injection by a cutting process in a depth of about 0.100 to 0.180 inches as measured from the top of the piston. However, other depths are possible when the hardness and material of the piston are considered. The cutting process may be better understood with reference to fig. 39A. In one embodiment of the invention, the slit 260 is cut using a thin blade 290 having a sharp edge made of metal such as titanium or stainless steel. The blade is mounted to a coupler or shaft 292 that is connected to a prior art ultrasonic generator 294 that preferably has an operating range of about 20kHz to about 40 kHz. An exemplary generator includes the Branson 2000aed model. The piston 258 is then placed in a fixture 296, such as a pedestal or roller, with the neck section directly adjacent the blade 290. The ultrasonic generator 294 is then energized while simultaneously moving the blade coaxially into the piston and rotating the blade. Once the slit 260 has been made, the blade is de-energized and withdrawn away from the piston. Alternatively, the vibrating blade may be held stationary and a piston mounted on a base or drum 296 moved toward the vibrating blade to form the slit.

In one embodiment, helical cutting is similar to a screw operation, which is a combination of rotation by a certain angle (referred to as the screw angle) about the longitudinal axis of the piston combined with translation by a certain distance along the longitudinal axis of the piston. In this embodiment, the upper slit section 262 is formed and vertically aligned along the longitudinal axis of the piston as the blade begins to translate through the neck section 156. The lower slit section 264 is formed when the advancing blade is rotated at an angle about the longitudinal axis of the piston. The lower slit section 264 partially wraps around the circumference of the neck 156. The slit 260 divides the neck 156 into an upstream section 268a defined on one side or above the slit 260 and a downstream section 268b defined on the opposite side or below the slit 260.

As shown in fig. 39B, the cutting process for creating the helical slit 260 may also be performed by mounting the piston 258 in a fixture 310, such as a mounting pin or similar device, in a vertical orientation with the open end of the piston 258 facing downward. In this implementation, a straight single blade 312 made of, for example, stainless steel or similar material is used for cutting. The straight cutting blade 312 may have a wall thickness of about 0.010 inch to 0.015 inch, preferably about 0.014 inch. With the cutting side of the blade facing downward, the blade may be mounted in the cartridge 214 of a robotic cutter 316 (e.g., a 3-axis Yamaha YK250X high speed Scara robot or any suitable device). The robotic cutter 316 initially moves the blade 312 into a cutting position directly above the top and centerline of the vertically positioned piston 258. Causing the blade to move downward to cut along the Z axis of the piston 258. As it moves downwardly, the blade is rotated at a constant rate at an angle of rotation of between about 20 and 90 degrees, thereby forming a partial helix. It should be understood that the rotation of the blade may be clockwise or counterclockwise, and the total depth measured from the top surface is about 0.100 inches to about 0.180 inches, which may vary depending on the material and hardness of the piston. In one embodiment, the cut is counterclockwise such that when a syringe is inserted and rotated counterclockwise to engage the threads on the valve housing, the clockwise rotation facilitates opening the slit for fluid flow. Thereafter, rotating the syringe counterclockwise to remove the syringe from the valve housing facilitates closing the slit.

Fig. 34 is a semi-schematic perspective view of the piston 258 of fig. 30-33. FIG. 34 is a depiction of the piston 258 inside a valve housing, such as the valve housing 302 (FIG. 37) that forms the valve assembly 272, which is not shown in FIGS. 34-36 for clarity. In practice, however, the valve housing may be any of the valve housings discussed above or as shown and discussed below with reference to fig. 37. A partial cross-sectional perspective view of the tip 69 of the medical implement positioned at the top surface 162 of the piston is shown. Just prior to opening the valve assembly 272, the piston 258 is in a first or ready position that blocks fluid flow from between the inlet and outlet of the valve housing, as previously discussed. Compressing upper flange 158 circumferentially against the inner wall surface of the inlet nozzle to hold piston neck sections 268a and 268b together compresses slit 260 to close the fluid flow path forming a fluid tight seal.

FIG. 35 is a semi-schematic perspective view of the valve assembly of FIG. 34 with the tip 69 partially inserted into the inlet nozzle of the valve housing. FIG. 35 is a depiction of the tip 69 being inserted into the inlet nozzle to a point in the valve housing where the slit 260 of the piston and the piston neck sections 268a and 268b are being compressed vertically along the longitudinal axis of the piston. The slit 260 provides relief for the neck 156 from compression such that the neck sections 268a and 268b begin to move or diverge relative to each other along the slit. Upon further compression of the piston (fig. 35), the gap formed by the two neck sections 268a, 268b opens further to form a conduit between the inlet and the outlet, with a portion of the conduit being provided by the interior surface of the housing. Accordingly, one aspect of the present embodiments is understood to include a valve comprising a piston having an upper neck section comprising a flange, a lower neck section, a body section, and a base flange located within a housing, and wherein the piston is compressible and forms a flow path across the entire circumference of the flange of the upper neck section. The piston further forms a helical flow path through at least a portion of the neck section so as to provide a gap through an exterior surface of the neck section.

In a particular application of the valve assembly with the preferred piston 258 of the present embodiment, a combined translational and rotational force is applied to the piston through the tip 69 of the syringe. This is typically the case, for example, if the syringe has a threaded collar configured to threadedly engage with the inlet of the valve assembly in a luer lock arrangement. Because the slit 260 is cut as a spiral, the piston neck sections 268a and 268b react to the tip 69 by "twisting" or rotating about the longitudinal axis of the piston. The twisting action causes the sections 268a and 268b to rotate relative to each other about the screw axis in the enlarged lower section 82 of the valve housing (fig. 37). As the piston neck sections 268a and 268b twist, they move in opposite directions relative to each other, causing the slit 260 to diverge and the gap to widen at the upper slit section 262. The separation forms a gap 66 at the upper slot section 262 that extends across the top surface 162. The gap 66 forms a fluid path for fluid flow from the tip 69 through the valve or toward the tip if sampling is to be performed via the valve assembly 272. At the same time, under the compressive load of the tip 69, the pliable and resilient base 146 begins to buckle and twist. Thus, the piston 258 is understood to have a helical cut along an orientation such that when the syringe is screwed down to the valve housing and the tip 69 imparts a combined rotational and translational force to the piston, the slit opens or widens. Conversely, when the syringe is removed from the valve housing, reverse rotation of the syringe causes the slit to close to form a fluid tight seal, which is further facilitated by the geometry of the housing inlet relative to the upper neck section of the piston.

FIG. 36 is a semi-schematic perspective view of the valve assembly 272 of FIG. 35 in a second position showing the tip 69 of the medical implement in a fully inserted position in the inlet nozzle of the valve housing. The tip 69 stops in the second position from further advancement due to the relative geometry of the tip 69 and the inlet nozzle of the valve housing. As the upper and lower neck sections 268a, 268b continue to twist away from each other, the gap 66 at the upper slit section 262 is further widened and the gap at the lower slit section 264 is widened. The pliable and resilient base 146 is further compressed and the random folds become more pronounced. Fluid flow from the medical implement may now flow through the lumen 274 defined by the tip 69, through the gap 66, and through the flow space defined by the exterior surface of the piston and the interior surface of the valve housing. The flow continues until it exits the outlet nozzle of the valve housing.

After the tip 69 is removed from the inlet nozzle of the valve housing, the pliable and resilient piston base 146 recoils and returns to its less compressed position. The spring back acts to push the neck section 156 proximally towards the opening of the inlet nozzle. When the axial compression on neck section 156 is removed, piston neck sections 268a and 268b begin to "unwrap" due to the resiliency of the piston and the counter-rotation of the syringe tip. The neck sections 268a and 268b unwrap until they return to their original positions. The interior surfaces of the slit remain pushed together due to the restriction or smaller interior circumference of the inlet nozzle near the opening of the valve housing, which acts to keep the gap 66 closed and terminate fluid communication between the inlet and outlet of the invisible valve housing. It will be appreciated that while circumferential force is used to help keep the gap 66 closed, the internal surfaces of the slit remain in contact until forced open by the application of axial compression of the neck section.

In one embodiment, the piston 258 may be used in a Y-site valve housing 304 as shown in fig. 38. In the Y-site valve housing 304, an auxiliary inlet 306 is formed in the housing. An auxiliary inlet 306 is formed in a leg of the housing 304 separate from the leg for receiving the piston 258. The housing 302 may be molded as one single piece part with two legs, as shown, or it may be made of different parts that are then solvent welded together or otherwise joined using well known techniques.

In yet another aspect of the invention, the piston 258 may be impregnated, coated, or both impregnated and coated with an antimicrobial agent, as described in application No. 11/942,163, filed on 11/19/2007, which was previously incorporated herein by reference. Alternatively or in addition thereto, the valve housing for housing the piston may also be impregnated or coated with an antimicrobial agent.

While limited embodiments of needle-free access valve assemblies and components thereof have been particularly described and illustrated herein, many modifications and variations will be apparent to those skilled in the art. For example, various valves may incorporate luer locks rather than luer threads, medical implements may include luer locks, the material of choice may be opaque or translucent, different colors may be used, dimensions may vary, and the like. Furthermore, it is to be understood and contemplated by the present disclosure that features specifically discussed for one valve embodiment may be selected for inclusion within another valve embodiment as long as the functions are compatible. For example, certain curvatures and contours incorporated in one valve may be incorporated in another valve for aesthetic appeal and improved functionality, such as for improved gripping purposes. It should be understood, therefore, that a valve assembly and its components constructed in accordance with the principles of the present invention may be embodied other than as specifically described herein. The invention is also defined in the following claims.

Claims (18)

1. A valve assembly, comprising:

a valve housing having an interior cavity, a bottom opening, and an inlet nozzle having an inlet opening and an interior wall surface along a central axis;

a piston positioned inside the valve housing having a flange, a neck section, a body section, and a base; the piston further includes a slit having a first slit surface and a second slit surface, the slit extending radially across two opposing outer surface sections of the flange and longitudinally in a direction of the inlet opening toward the bottom opening and through at least a portion of the neck section below the flange, the first and second slit surfaces extending through at least a portion of the neck section below the flange, and the slit making an angle about the central axis;

wherein the slits are configured in a spiral pattern and comprise an upper slit section extending in a radial direction to penetrate the flange and two lower slit sections extending in two opposite directions from opposite sides of the upper slit section, respectively, as if being at least partially wound in opposite directions on the circumference of the neck section in a twisted manner.

2. The valve assembly of claim 1, wherein the first slit surface and the second slit surface move from a first position in which the surfaces are in contact to a second position in which a gap is formed between the surfaces.

3. The valve assembly of claim 2, wherein a portion of the body section buckles as the piston moves from the first position to the second position.

4. The valve assembly of claim 2, wherein the first slit surface and the second slit surface rotate in opposite directions about the central axis when moving from the first position to the second position.

5. The valve assembly of claim 1, wherein the flange is in contact with the interior wall surface of the inlet nozzle to force at least a portion of the first and second slit surfaces into contact with one another.

6. The valve assembly of claim 1, wherein an antimicrobial agent is formed on at least one of the piston and the valve housing.

7. The valve assembly of claim 1, further comprising a plurality of threads disposed at the inlet nozzle of the valve housing.

8. The valve assembly of claim 1, wherein the valve housing includes a second inlet opening.

9. A valve assembly, comprising:

a piston positioned inside a valve housing, the piston comprising a flange, a neck section, a body section comprising an upper section and a lower section defining an interior cavity, an exterior wall surface, and a base;

the valve housing including an inlet nozzle having an inlet opening, a body section defining an interior cavity having an interior wall surface, and a bottom opening;

wherein the neck section of the piston comprises a slit formed in a helical configuration across the entire flange and through at least a portion of the neck section to the outer wall surface of the piston; the slit and the inner wall surface of the valve housing define a fluid space for fluid flow through the inlet nozzle and out of the bottom opening, and

wherein the slit comprises an upper slit section extending in a radial direction to extend through the flange and two lower slit sections extending in two opposite directions from opposite sides of the upper slit section, respectively, as if being at least partially wound in opposite directions on the circumference of the neck section in a twisted manner.

10. The valve assembly of claim 9, wherein the helical configuration of the slit comprises rotation of the slit at an angle about a central axis of the piston.

11. The valve assembly of claim 9, wherein the helical configuration of the slit comprises two cutting fronts pointing in opposite directions to each other.

12. The valve assembly of claim 9, wherein the valve housing comprises a Y-site valve housing.

13. The valve assembly of claim 9, wherein at least one of the piston and the valve housing comprises an antimicrobial composition.

14. The valve assembly of claim 10, wherein the slit comprises a first slit surface and a second slit surface that move from a first position in which the surfaces are in contact to a second position in which a gap is formed between the surfaces to form a portion of the fluid space.

15. The valve assembly of claim 14, wherein the first slit surface and the second slit surface rotate in opposite directions about the central axis when moving from the first position to the second position.

16. The valve assembly of claim 14, wherein a portion of the body section buckles as the piston moves from the first position to the second position.

17. A method of making a piston for use in an access port valve, the method comprising:

molding a piston comprising a flange, and a neck section of reduced diameter compared to a body section defining an internal cavity; and

cutting a slit in the neck section;

wherein the cutting step comprises rotating a blade through an angle about an axis of the piston while translating the blade a distance along the axis to form a helical configuration such that the slit comprises an upper slit section extending in a radial direction to extend through the flange and two lower slit sections extending in two opposite directions from opposite sides of the upper slit section, respectively, as if twisted at least partially wrapped around the circumference of the neck section in opposite directions.

18. The method of claim 17, wherein the piston comprises an antimicrobial composition.