Needleless Valve

It is a well known practice to administer medications and other types of solutions to a patient with an intravascular administration set, consisting of a needle inserted into a blood vessel of the patient, flexible tubing connected to the needle, and various fittings for connecting fluid components to the flexible tubing. The fluid components can be a bottle of parenteral fluid, a bottle of a supplementary fluid, or a syringe of medication. Typically, one solution will be connected to flow continuously into the patient, while another solution will be added to the first solution at a branch connector located in the flexible tubing. Such connectors are often called "Y-sites". A Y-site is usually a sealed entry point having an elastomeric plug or septum. Medication can be introduced into the Y-site by injection through the elastomeric septum with a second needle, or by connecting a blunt connector to the Y-site, with flow through or past the septum being achieved by various means. Many connector devices in addition to the Y-site use the elastomeric septum for connection of fluid flow paths.

A major drawback of using a needle to penetrate the septum is that the use of sharp needles in any device frequently results in the occurrence of "needle stick" accidents, in which health care personnel are accidentally wounded by the needle. The needle stick accident can occur during insertion of the needle into the Y-site, or after use of the needle and before disposal. Needle stick accidents often spread infectious diseases, such as the HIV virus. This risk arises any time a sharp needle is used to connect two fluid flow components, not being restricted to the use of a Y-site in an I. V. set. Various devices have therefore been developed, which do not use a sharp needle, using instead a blunt device to connect to the Y-site or other connector. Most common among the "needle-less" connectors is the use of a luer connector, with an elastomeric septum in the female component, such as the Y-site, and a blunt male connector for connecting thereto. When the male luer connector is connected to the female luer connector, the septum is either pierced by a concealed piercing element, or the septum is otherwise penetrated or bypassed.

In a needle-less connector, there is typically a certain amount of dead space within the connector in which the septum is mounted, such as the Y-site. This allows for shifting or deformation of the septum, to achieve fluid flow. Unfortunately, dead space is undesirable, because it allows for the injection of air or contaminants into the patient along with the medication, accumulation of medication in a stagnant space, or coagulation of accumulated blood.

Further, needle-less connectors often allow the generation of a vacuum when the luer connector is disassembled. The vacuum results when a movable septum moves outwardly within the Y-site or other connector, upon disconnection, creating a lower than ambient pressure in the connector. If the septum is not sealed sufficiently to withstand the pressure differential before the connectors lose contact, flow from the ambient into the connector can occur. This vacuum can draw contaminants from the environment into the Y-site.

Another problem frequently associated with pre-slit needle-less connector devices is the failure of the opening in the septum to completely close at its outermost end, sometimes leaving a partially open slit in which contaminants can accumulate. Prior to use of the connector, it is common practice to wipe clean the exterior surface of the septum with alcohol, to remove contamination. However, if the septum has a slit which fails to completely close, the outer extremity of the slit can harbor contaminants which can not be effectively cleaned by wiping.

Finally, many known needle-less connectors suffer from the failure to seal against a required pressure differential. This can result from the absence of any structure in the housing to positively close the septum upon withdrawal of the blunt connector.

It is desirable, therefore, to have a needle-less connector which can be incorporated into a Y-site or any other type of fluid flow connector, which will limit the amount of dead space, counteract the formation of a vacuum, completely seal upon withdrawal of the associated connector, and effectively seal against significant pressure differentials.

The present invention is a needle-less valve connector which employs a pre-slit elastomeric septum within a rigid housing such as a Y-site. The septum is capable of axial movement proximally and distally within the Y-site. Connection of a blunt connector, such as a male luer, to the female fitting on the Y-site pushes the septum in the distal direction. A spring or other biasing member biases the septum toward the proximal direction. The slit through the septum is held in the closed position, when the septum is in the proximal position, by an interference fit between the inside surface of the housing and the peripheral surface of the septum, with the interference fit causing an inward radial compression of the septum, orthogonal to the slit axis. The interference fit must be sufficient to seal the slit against a pressure differential of at least 30 psi. The interference fit can be caused by using a septum having an elliptical cross section and a housing having a circular cross section, with at least one axis of the septum being larger than the inside diameter of the housing, that being the axis of the septum cross section which is orthogonal to the slit axis. Conversely, the septum could have a circular cross section, and the housing could be irregular or elliptical. In this type of device, the minor axis of the housing cross section would be positioned orthogonal to the slit axis in the septum. The outer, or proximal, end surface of the septum can be shaped with a concave contour which places the outer end of the slit at the axial location at which sufficient inward radial stress exists to completely close the slit when the septum is in the proximal position. This prevents the existence of a crevice at the outer extremity of the slit when the valve is closed.

When the blunt connector is connected to the valve, the septum is pushed to a distal position, where another contour in the housing either applies a radial force to the septum to open the slit, or allows the septum to expand, thereby opening the slit. This opening of the slit can be achieved in three ways. First, another interference fit between the inside surface of the housing and the peripheral surface of the septum can be used to apply inward radial stress to the septum, parallel to the slit axis, causing the slit to open as the septum moves in the distal direction. Here again, the septum could be irregularly shaped and the housing circular, or the septum could be circular and the housing irregular. Second, a hollow cannula in the distal end of the housing can be aligned with the slit to forcibly enter the distal end of the slit and apply outward radial stress to the septum, orthogonal to the slit axis, causing the slit to open as the septum moves in the distal direction. These two methods of applying radial stress to open the slit can be used separately, or in combination. Third, a cavity in the housing, which is at least as large in cross section as the septum, allows the septum to expand to a condition in which the slit is no longer held closed.

The axial locations of the housing structures which vary the radial loads to open and close the slit are selected to insure that the septum is sealed at all appropriate times. The structure which closes the slit is positioned to close and seal the slit before the septum fully reaches the proximal position, thereby maintaining a seal between the blunt connector and the septum until after the slit is sealed, preventing vacuum contamination. The structure which opens the slit, or allows the slit to open, is positioned so that the slit will open only after sufficient force is applied to the septum by the blunt connector, to insure that a seal exists between the blunt connector and the septum before opening of the slit.

The novel features of this invention, as well as the invention itself, will be best understood from the attached drawings, taken along with the following description, in which similar reference characters refer to similar parts, and in which:

FIG. 1 is a perspective view of a first embodiment of an elliptical septum and a spring member according to the present invention, in the unconstrained condition;

FIG. 2 is a longitudinal section, orthogonal to the slit axis, of the septum shown in FIG. 1;

FIG. 3 is a longitudinal section, parallel to the slit axis, of the septum shown in FIG. 1;

FIG. 4 is a perspective view of a second embodiment of an elliptical septum and a spring member according to the present invention, with the septum having a higher aspect ratio between its major and minor axes;

FIG. 5 is a longitudinal section, orthogonal to the slit axis, of the septum shown in FIG. 4;

FIG. 6 is a longitudinal section, parallel to the slit axis, of the septum shown in FIG. 4;

FIG. 7 is a partial section of a first embodiment of a female valve connector housing according to the present invention, with wings projecting inwardly to apply inward radial stress to the septum in the distal position;

FIG. 8 is a longitudinal section, orthogonal to the plane of the wings, of the housing shown in FIG. 7;

FIG. 9 is a longitudinal section, parallel to the plane of the wings, of the housing shown in FIG. 7;

FIG. 10 is a partial section of the housing shown in FIG. 7, showing the introduction of a blunt connector;

FIG. 11 is a longitudinal section, orthogonal to the plane of the wings and orthogonal to the slit axis, of the septum shown in FIG. 1 installed in the housing shown in FIG. 7, with the septum in the proximal position;

FIG. 12 is an end view of the valve assembly shown in FIG. 11;

FIG. 13 is a longitudinal section, parallel to the plane of the wings and parallel to the slit axis, of the septum shown in FIG. 1 installed in the housing shown in FIG. 7, with the septum in the distal position;

FIG. 14 is an end view of the valve assembly shown in FIG. 13;

FIG. 15 is a perspective view of a second embodiment of a female valve connector housing according to the present invention;

FIG. 16 is a longitudinal section of the housing shown in FIG. 15, with a blunt cannula projecting in the proximal direction;

FIG. 17 is a perspective view of the housing shown in FIG. 15, showing the introduction of a blunt connector;

FIG. 18 is a longitudinal section of the septum shown in FIG. 4 installed in the housing shown in FIG. 15, with the septum in the proximal position;

FIG. 19 is an end view of the valve assembly shown in FIG. 18;

FIG. 20 is a longitudinal section of the septum shown in FIG. 4 installed in the housing shown in FIG. 15, with the septum in the distal position;

FIG. 21 is an end view of the valve assembly shown in FIG. 20;

FIG. 22 is a perspective view of a third embodiment of an elliptical septum and a spring member according to the present invention, with the septum having a higher aspect ratio between its major and minor axes, and with the slit axis being aligned with the major axis of the septum;

FIG. 23 is a longitudinal section, parallel to the slit axis, of the septum shown in FIG. 22;

FIG. 24 is a longitudinal section, orthogonal to the slit axis, of the septum shown in FIG. 22;

FIG. 25 is a partial section of a third embodiment of a female valve connector housing according to the present invention, with an elliptical distal interior contour;

FIG. 26 is a longitudinal section, along the major axis of the elliptical interior contour, of the housing shown in FIG. 25;

FIG. 27 is a longitudinal section, along the minor axis of the elliptical interior contour, of the housing shown in FIG. 25;

FIG. 28 is a longitudinal section, orthogonal to the slit axis, of the septum shown in FIG. 22 installed in the housing shown in FIG. 25, with the septum in the proximal position;

FIG. 29 is an end view of the valve assembly shown in FIG. 28;

FIG. 30 is a longitudinal section, orthogonal to the slit axis, of the septum shown in FIG. 22 installed in the housing shown in FIG. 25, with the septum in the distal position; and

FIG. 31 is a sectional view of the valve assembly shown in FIG. 30.

FIG. 1 shows a hollow, combination elastomeric valve element 10 comprising a septum 12 and a spring element 14. In this view, the valve element 10 is in the unconstrained condition. The spring element can be a resilient elastomeric cylinder as shown, or it can be a spring, such as a coiled spring, in substantially the same location. If a coiled spring is used, it can be separate from the valve element 10 or integrated into the valve element 10. The septum 12 shown has an elliptical cross section, with a major transverse dimension, or major axis 16, and a minor transverse dimension, or minor axis 18. The septum 12 has a peripheral surface 13 and a proximal end surface 15. The septum 12 also could be another non-cylindrical shape without departing from the spirit of the invention. Further, depending upon the shape of other elements of the valve, the septum 12 could even have a cylindrical shape, as will be discussed later. A slit 20 is formed longitudinally through the septum 12. The cross section of the slit 20 can be a flat line, or slightly oval as shown, with a slit plane 22. The slit plane 22 is orthogonal to the major transverse dimension 16 of the septum 12. The end surface 15 has a concave surface 17 which ensures that the outer end of the slit 20 remains closed.

FIG. 2 shows a longitudinal cross section of the valve element 10, with the section being taken orthogonal to the slit plane 22. The longitudinal axis 24 of the valve element 10 can lie in the slit plane 22 as shown, or it can be offset therefrom. The valve element 10 also can have a sealing bead 26 near its distal end, to facilitate sealing the valve element to a housing, such as a Y-site. The configuration and location of the sealing member 26 can vary, to match the housing in which the valve element 10 is used. There can also be a tapered neck 28 in the valve element 10, to allow relative axial movement between the septum 12 and the remainder of the valve element 10. The neck 28 is also an alternative location for a spring element. The neck 28 can be provided with slots 29 to provide clearance for housing structure, as will be explained below. FIG. 3 shows another longitudinal cross section of the valve element 10, with the section being taken at, or in a plane parallel to, the slit plane 22. It can be seen from FIGS. 1 through 3 that the aspect ratio between the major transverse dimension 16 and the minor transverse dimension 18 of the septum 12 is not very much greater than unity, so the septum 12 is not far from being cylindrical in this embodiment.

FIG. 4 shows a second embodiment of the elastomeric valve element 10', with a septum 12' and a spring element 14. Here again, the slit plane 22 is orthogonal to the major transverse dimension 16 of the septum 12'. FIG. 5 shows a longitudinal cross section of the valve element 10', with the section being taken orthogonal to the slit plane 22. The slit plane 22 can contain the longitudinal axis 24 of the valve element 10, or it can be offset therefrom. FIG. 6 shows another longitudinal cross section of the valve element 10', with the section being taken at, or parallel to, the slit plane 22. In this embodiment, the aspect ratio between the major transverse dimension 16 and the minor transverse dimension 18 is much higher than in the first embodiment, making the septum 12' further from a cylindrical shape. A higher aspect ratio could be selected to apply higher radial stress to the septum 12, 12', or to provide more room for expansion of the minor transverse dimension 18 of the septum 12, 12'.

FIG. 7 shows a first embodiment of a rigid tubular connector housing 30 with which the valve element 10 can be used. The connector housing 30 includes generally a hollow, substantially cylindrical barrel 32 and a substantially cylindrical tubular valve housing 34 formed on a proximal end of the barrel 32. The connector housing 30 can also be fitted with a flange 50 for sealing against the sealing bead 26 of the valve element 10, if appropriate for the type of connector. The configurations shown for the distal ends of the connector housing 30 and the valve element 10, such as the flange 50 and the sealing element 26, are for illustration purposes only, with the actual configuration being adapted to the actual connector being designed. The tubular valve housing 34 has an inside surface 36 which interacts with the peripheral surface 13 of the septum 12, to place inward radial stress upon the septum 12 as desired to open or close the slit 20.

The interaction between the inside surface 36 of the valve housing 34 and the peripheral surface 13 of the septum 12 has two modes, one occurring when the septum 12 is positioned near the proximal end 38 of the valve housing 34 and the other occurring when the septum 12 is positioned near the distal end 40 of the valve housing 34. In this embodiment, the proximal portion of the inside surface 36 of the valve housing 34 has a circular cross section, as can be seen in FIGS. 8 and 9. The distal portion of the inside surface 36 of the valve housing 34 has two diametrically opposed inwardly sloping wings 42, 44. The distance between the wings 42, 44 is less than the internal diameter of the proximal portion of the valve housing 34, and less than the minor transverse dimension 18 of the septum 12. Except for the wings 42, 44, the internal surface 36 of the distal portion of the valve housing 34 has a conical surface 46 tapering outwardly to a larger diameter 48 at the distal end 40. As mentioned above, instead of making the septum 12 with an elliptical cross section and the valve housing interior surface 36 with a circular cross section, the septum 12 could be circular and the valve housing 34 could be elliptical. Any such combination of corresponding shapes of the septum 12 and the valve housing 34 which results in an inward radial stress being placed on the septum 12 will comport with the spirit of the invention.

FIGS. 10 through 14 illustrate the interaction of the valve housing 34 and the septum 12, when assembled as a valve assembly 60. The particular valve housing 34 and septum 12 shown are chosen for illustration purposes only, to demonstrate the features of the present invention. Other appropriate shapes could be used as well, as long as they impose the radial stresses on the septum that are required for the present invention. The opening and closing of the slit 20 in the septum 12 are accomplished by moving the septum 12 axially within the valve housing 34, with movement of the septum 12 being accomplished by mating a blunt connector BC to the proximal end 38 of the valve housing 34, as shown in FIG. 10. For example, the proximal end 38 of the valve housing 34 could have a female luer fitting formed thereon, as is well known in the art, and the blunt connector BC could be found within a matching male luer connector. The spacing between the wings 42, 44 is designed to allow insertion of the blunt connector BC.

FIG. 11 shows the valve element 10 mated with the connector housing 30, with the septum 12 in the proximal position within the valve housing 34. The state shown is the normal disconnected state of the connector. The diameter of the proximal portion of the inside surface 36 of the valve housing 34 is smaller than the major transverse dimension 16 of the septum 12. This applies an inward radial compression to the septum 12 to close the slit 20, as seen in FIG. 12, against a pressure differential of at least 30 psi. When the apparatus is in the configuration shown in FIG. 12, the wings 42, 44 extend into the slots 29, so that the wings 42, 44 are not imposing a radial stress upon the septum 12. The proximal end surface 15 of the septum 12 preferably has a concave contour 17 shaped to ensure that the inward radial stress applied completely closes the slit, preventing the occurrence of a crevice.

As seen in FIG. 13, when the blunt connector BC is mated with the proximal end 38 of the valve housing 34, the septum 12 is pushed distally, partially compressing the spring element 14 and the valve neck 28. This places the septum 12 between the wings 42, 44, which are aligned with the slit plane 22. Since the space between the wings 42, 44 is smaller than the minor transverse dimension 18 of the septum 12, the wings 42, 44 impose inward radial stress on the septum 12 in line with the slit plane 22, causing the slit 20 to open as shown in FIG. 14. When the blunt connector BC is disconnected from the valve housing 34, the spring element 14 maintains the proximal end surface 15 of the septum 12 sealed against the blunt connector BC, until the septum 12 has re-entered the constriction at the proximal end of the valve housing 34. This insures that the slit 20 is closed and sealed before the blunt connector BC loses contact with the septum 12, preventing vacuum contamination of the valve assembly 60.

FIGS. 15 and 16 show a second embodiment of a rigid tubular connector housing 30' with which the valve element 10, 10' can be used. The connector housing 30' includes generally a hollow, substantially cylindrical barrel 32 and a substantially cylindrical tubular valve housing 34' formed on a proximal end of the barrel 32. The tubular valve housing 34' has an inside surface 36' which interacts with the peripheral surface 13 of the septum 12, 12' to place inward radial stress upon the septum 12, 12' when the septum 12, 12' is in the proximal position, to close the slit 20.

The interaction between the inside surface 36' of the valve housing 34' and the peripheral surface 13 of the septum 12, 12' has two modes, one occurring when the septum 12, 12' is positioned near the proximal end 38 of the valve housing 34' and the other occurring when the septum 12, 12' is positioned near the distal end 40 of the valve housing 34'. The proximal portion of the inside surface 36' of the valve housing 34' has a circular cross section. The valve housing 34' is different from the first embodiment, in that it has no wings 42, 44. The internal surface 36' of the distal portion of the valve housing 34' has a conical surface 46' tapering outwardly to a larger diameter 48 at the proximal end 40. Opening of the slit 20 is accomplished by a hollow rigid cannula 62 mounted to the flange 50 by means such as solvent bonding, and extending proximally within the barrel 32. The cannula 62 extends proximally into the distal portion of the valve housing 34'. The proximal end 64 of the cannula 62 aligns with the slit 20 of the septum 12, 12'. As mentioned before, instead of making the septum 12, 12' with an elliptical cross section and the valve housing interior surface 36' with a circular cross section, the septum 12, 12' could be circular and the valve housing 34' could be elliptical. Any such combination of corresponding shapes of the septum 12, 12' and the valve housing 34' which results in an inward radial stress being placed on the septum 12, 12' will comport with the spirit of the invention.

FIGS. 17 through 21 illustrate the interaction of the valve housing 34' and the septum 12' when assembled as a valve assembly 60'. The particular valve housing 34' and septum 12' shown are chosen for illustration purposes only, to demonstrate the features of the present invention. Other appropriate shapes could be used as well, as long as they impose the radial stresses on the septum that are required for the present invention. The opening and closing of the slit 20 in the septum 12' are accomplished by moving the septum 12' axially within the valve housing 34', with movement of the septum 12' being accomplished by mating a blunt connector BC to the proximal end 38 of the valve housing 34', as shown in FIG. 17. For example, the proximal end 38 of the valve housing 34' could have a female luer fitting formed thereon, as is well known in the art, and the blunt connector BC could be found within a matching male luer connector. The internal diameter of the surface 36' is designed to allow insertion of the blunt connector BC.

FIG. 18 shows the valve element 10' mated with the connector housing 30', with the septum 12' in the proximal position within the valve housing 34'. Valve element 10 could also be used. The state shown is the normal disconnected state of the connector. The diameter of the proximal portion of the inside surface 36' of the valve housing 34' is smaller than the major transverse dimension 16 of the septum 12'. This applies an inward radial compression to the septum 12' to close the slit 20, as seen in FIG. 19. The proximal end surface 15 of the septum 12' preferably has a concave contour shaped to insure that the inward radial stress applied completely closes the slit, preventing the occurrence of a crevice.

As seen in FIG. 20, when the blunt connector BC is mated with the proximal end 38 of the valve housing 34', the septum 12' is pushed distally, partially compressing the spring element 14 and the valve neck 28. This causes the septum 12' to contact the proximal end 64 of the hollow cannula 62. As the hollow cannula 62 enters the slit 20, it imposes outward radial stress on the septum 12', causing the slit 20 to open as shown in FIG. 21. It is important to note that internal contours of the valve housing 34' and the axial position of the proximal end 64 of the cannula are designed so that the proximal end 64 of the cannula 62 does not extend far enough in the proximal direction to contact the blunt cannula BC when the blunt cannula BC has been inserted completely into the connector housing 30'. This is because, even though the length, taper angle, and outside diameter of the blunt connector BC are controlled by industry standards, the internal diameter of the blunt connector BC is not a controlled dimension.

When the blunt connector BC is disconnected from the valve housing 34', the spring element 14 maintains the proximal end surface 15 of the septum 12' sealed against the blunt connector BC, until the septum 12' has re-entered the constriction at the proximal end of the valve housing 34'. This insures that the slit 20 is closed and sealed before the blunt connector BC loses contact with the septum 12', preventing vacuum contamination of the valve assembly 60'.

FIG. 22 shows a third embodiment of the valve element 10" according to the present invention. This embodiment is a hollow, combination elastomeric valve element 10" comprising a septum 12" and a spring element 14. In this view, the valve element 10" is in the unconstrained condition. The spring element can be a resilient elastomeric cylinder as shown, or it can be a spring, such as a coiled spring, in substantially the same location. If a coiled spring is used, it can be separate from the valve element 10" or integrated into the valve element 10". The septum 12" shown has an elliptical cross section, with a major transverse dimension, or major axis 16, and a minor transverse dimension, or minor axis 18. This particular embodiment of the septum has a fairly high aspect ratio. The septum 12" has a peripheral surface 13" and a proximal end surface 15. The septum 12" also could be another non-cylindrical shape without departing from the spirit of the invention. Further, depending upon the shape of other elements of the valve, the septum 12" could even have a cylindrical shape. A slit 20 is formed longitudinally through the septum 12". The cross section of the slit 20 can be a flat line, or slightly oval as shown, with a slit plane 22. The slit plane 22 in this embodiment is aligned with the major transverse dimension 16 of the septum 12". The end surface 15 has a concave surface 17 which ensures that the outer end of the slit 20 remains closed.

FIG. 23 shows a longitudinal cross section of the valve element 10", with the section being taken at the slit plane 22. The longitudinal axis 24 of the valve element 10" can lie in the slit plane 22, or it can be offset therefrom. The valve element 10" also can have a sealing bead 26 near its distal end, to facilitate sealing the valve element to a housing, such as a Y-site. The configuration and location of the sealing member 26 can vary, to match the housing in which the valve element 10" is used. There can also be a tapered neck 28 in the valve element 10", to allow relative axial movement between the septum 12" and the remainder of the valve element 10". The neck 28 is also an alternative location for a spring element. FIG. 24 shows another longitudinal cross section of the valve element 10", with the section being taken orthogonal to the slit plane 22. It can be seen from FIGS. 22 through 24 that the aspect ratio between the major transverse dimension 16 and the minor transverse dimension 18 of the septum 12" is fairly high, so the septum 12" is far from being cylindrical in this embodiment.

FIG. 25 shows a third embodiment of a rigid tubular connector housing 30" with which the valve element 10" can be used. The connector housing 30" includes generally a hollow, substantially cylindrical barrel 32 and a substantially cylindrical tubular valve housing 34" formed on a proximal end of the barrel 32. The connector housing 30" can also be fitted with a flange 50 for sealing against the sealing bead 26 of the valve element 10", if appropriate for the type of connector. The configurations shown for the distal ends of the connector housing 30" and the valve element 10", such as the flange 50 and the sealing element 26, are for illustration purposes only, with the actual configuration being adapted to the actual connector being designed. The tubular valve housing 34" has an inside surface 36" which interacts with the peripheral surface 13" of the septum 12", to place inward radial stress upon the septum 12" as desired to close the slit 20.

The interaction between the inside surface 36" of the valve housing 34" and the peripheral surface 13" of the septum 12" has two modes, one occurring when the septum 12" is positioned near the proximal end 38 of the valve housing 34" and the other occurring when the septum 12" is positioned near the distal end 40 of the valve housing 34". In this embodiment, the proximal portion of the inside surface 36" of the valve housing 34" has a circular cross section, as can be seen in FIGS. 26 and 27. The distal portion of the inside surface 36" of the valve housing 34" has a conical surface 46 tapering outwardly to an elliptical surface 48' at the distal end 40, as shown in FIGS. 26 and 27. As mentioned above, instead of making the septum 12" with an elliptical cross section and the proximal portion of the valve housing interior surface 36" with a circular cross section, the septum 12" could be circular and the proximal portion of the valve housing 34" could be elliptical. In the latter case, the distal portion of the inside surface 36" of the valve housing 34" would have a conical surface 46 tapering outwardly to a cylindrical surface 48' at the distal end 40. Any such combination of corresponding shapes of the septum 12" and the valve housing 34" which results in an inward radial stress being placed on the septum 12" by the proximal portion of the interior surface 36" will comport with the spirit of the invention.

FIGS. 28 through 31 illustrate the interaction of the valve housing 34" and the septum 12", when assembled as a valve assembly 60". The particular valve housing 34" and septum 12" shown are chosen for illustration purposes only, to demonstrate the features of the present invention. Other appropriate shapes could be used as well, as long as they vary the radial stresses on the septum that are required for the present invention. The opening and closing of the slit 20 in the septum 12" are accomplished by moving the septum 12" axially within the valve housing 34", with movement of the septum 12" being accomplished by mating a blunt connector BC to the proximal end 38 of the valve housing 34", as shown above relative to the other embodiments. For example, the proximal end 38 of the valve housing 34" could have a female luer fitting formed thereon, as is well known in the art, and the blunt connector BC could be found within a matching male luer connector.

FIG. 28 shows the valve element 10" mated with the connector housing 30", with the septum 12" in the proximal position within the valve housing 34". The state shown is the normal disconnected state of the connector. The diameter of the proximal portion of the inside surface 36" of the valve housing 34" is smaller than the minor transverse dimension 18 of the septum 12". This applies an inward radial compression to the septum 12" to close the slit 20, as seen in FIG. 29, against a pressure differential of at least 30 psi. The proximal end surface 15 of the septum 12 preferably has a concave contour 17 shaped to ensure that the inward radial stress applied completely closes the slit, preventing the occurrence of a crevice.

As seen in FIG. 30, when the blunt connector BC is mated with the proximal end 38 of the valve housing 34", the septum 12" is pushed distally, partially compressing the spring element 14 and the valve neck 28. This places the septum 12" in the elliptical cavity described by the elliptical surface 48'. Since the major and minor transverse dimensions of this elliptical cavity are larger than the major and minor transverse dimensions 16, 18 of the septum 12", the elliptical surface 48' does not impose any inward radial stress on the septum 12" in line with the slit plane 22. This allows the septum 12" to expand, causing the slit 20 to open as shown in FIG. 31. When the blunt connector BC is disconnected from the valve housing 34", the spring element 14 maintains the proximal end surface 15 of the septum 12" sealed against the blunt connector BC, until the septum 12" has re-entered the constriction at the proximal end of the valve housing 34". This insures that the slit 20 is closed and sealed before the blunt connector BC loses contact with the septum 12", preventing vacuum contamination of the valve assembly 60".

While the particular invention as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages hereinbefore stated, it is to be understood that this disclosure is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended other than as described in the appended claims.