Patent Publication Number: US-6669681-B2

Title: Needleless connector

Description:
This application is a continuation of U.S. Ser. No. 09/082,134, filed May 20, 1998, Now U.S. Pat. No. 6,261,282, which claimed the benefit of U.S. Provisional Application No. 60/047,172, filed May 20, 1997. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to needleless fluid connection devices and more specifically to a device for repeatedly establishing a sealed connection to a conduit or a container for medical applications. 
     BACKGROUND OF THE INVENTION 
     One very prevalent form of health care therapy is infusion or intravenous (“I.V.”) therapy whereby fluids possessing desired medication or other characteristics are infused into a patient over varying lengths of time. To practice this infusion therapy frequently a connection needs to be made between components for the transfer of fluid between the two components, along a fluid passageway and eventually to a patient. As an example, administration sets are widely used to administer liquids parenterally to a patient and other medical devices are connected to the administration set to provide the proper administration. 
     One widely used connector for making a connection between medical devices to establish a fluid passageway is a luer connection assembly. In the luer connection assembly, a male luer tip component or fitting having a frustoconical shape is inserted into a female luer component or fitting having a frustoconical shaped receiving cavity and opposing conical surfaces come into contact to form a sealed friction fit. 
     Until the connection is made, the passageway through each of the luer fittings and into the lumen of a component attached to the luer fitting is open to the environment. This lumen and the passageway through the luer connectors form a portion of the fluid passageway and must be sterile prior to use and then sealed against microbial ingress during use. Thus, these connection assemblies and the associated components are packaged in sterile packaging and the connections are typically made just prior to establishing fluid communication with a patient&#39;s venous system. 
     There are two general types of luer connection assemblies. One type is generally referred to as the luer slip where the connection is maintained by the friction fit between the male luer tip and female luer component. The other type is generally referred to as a luer lock connection whereby the male luer tip is encircled by an annular flange having a threaded internal surface. The female component includes a corresponding thread formed about the outer surface. Engaging the threaded flange to the threaded outside surface establishes the connection between the male luer tip and female component while preventing accidental disconnects. 
     To insure a universal luer connections among components provided by a multitude of manufacturers, luer connection assemblies are manufactured to comply with universal standards. Very important sets of standards such as ANSI and ISO standards. These standards includes standard dimensions for male slip and luer lock assemblies. Among these dimensional standards are standards which define the spacing or clearance between the annular locking flange and the male luer tip. Thus any female connection device configured to establish a connection to a standard male luer lock must be able to engage the luer tip and locking flange within this clearance or spacing. 
     Other standards in the ISO standards include several performance requirements for luer connections. One such requirement is that after a luer lock type connection is made, to prevent inadvertent disconnection, the luer connection should resist an axial removal force of 8 pounds and unscrewing torque less than 2.8 in/oz without disconnection. Luer connections should also hold a seal against 45 psi after a connection torque of 16 in/oz has been applied. In standard luer connections this resistance and sealing is supplied by the friction between the opposing conical surfaces. 
     Once a component of I.V. therapy is placed in fluid communication with the body, the fluid passageway should be sealed from the environment to prevent contamination and this passageway should also be sealed so as to not allow any leakage of bodily fluids into the environment However, most therapies require periodic access to the fluid passageway. Because the portion of the fluid passageway through a female luer connection component is open to the environment, these components will not form a sealed connection to the fluid passageway after the fluid passageway is placed in fluid communication with the body. 
     In one prevalent example of intravenous therapy, fluid containing a drug in solution is injected into a primary flow of fluid from an I.V. solution container through an administration set to a catheter extending within a vein. The drug containing fluid may be injected from a syringe, secondary medication set or the like, into the set where it mixes with the flowing fluid. In another prevalent example, fluid is injected directly into or withdrawn from a catheter extending within the body. In addition the catheters are flushed periodically to maintain patency by the injection of small amounts of saline or heparin. 
     As can be appreciated, it is highly desirable to maintain catheters and administration sets in service as long as possible without compromising the safety of the patient. Replacement of catheters and sets is time consuming and expensive. Therefore over the period of time of use of a set or catheter there may be many connections and disconnects. For example, there may be over 100 connections and disconnects to a connection site on a catheter or set before the catheter or set is replaced. In addition a connection may be made and that connection maintained for an extended period of time before disconnection. For example a connection may be made for up to seven days of “indwell” and yet the connection should still be capable of accepting intermediate and subsequent connections and disconnects without allowing leakage to the environment. 
     Another highly desirable attribute of a connector is the ability for such a connector to seal against pressurized fluid found within a set or for the connector to possess a certain leak pressure in excess of a desired pressure. For example it is desirable for a connector to have a leak pressure which is in excess of 20 p.s.i. for a short period of time such as when a bolus administration of drug is injected into a set and a leak pressure in excess of 6 p.s.i. of continuous pressure during infusion of medication. 
     In addition, a connector may be exposed to negative pressure particularly when such connector is located upstream of an inlet of an intravenous pump. Failure to prevent aspiration through a connector when the connector is exposed to negative pressure may lead to an aspiration of air and/or microbes into the fluid passageway. 
     Depending on the application, many other features may be desirable. Dead spaces within any connector which cannot be “flushed” should be minimized or eliminated as they may form an environment for microbial growth. Also, priming volume for the connector should be minimized. 
     Because intravenous therapy is practiced on a worldwide basis and millions of connection sites are used every year and the costs of components used in such therapy are a factor in the cost of therapy, any desired connector should be capable of being manufactured at high speeds and low cost. Generally the lower the number of parts making up a component, the lower the number of molds and high speed assembly devices both of which generally translate to lower capital expenditures and therefore lower costs. 
     On the other hand, whatever the connector configuration, it is highly desirable that the connector be capable of low defect manufacture. Even a small number of failure is generally unacceptable when a single failure may put a patient or health care provider at risk. 
     Moreover, it is also highly desirable that any surfaces around an inlet into a connector be able to be swabbed or otherwise disinfected. Typically unbroken or smooth surfaces facilitate swabbing and other disinfecting techniques. 
     As mentioned previously, although luer connectors are widely found in the medical environment such connections are generally not acceptable when many of the above described requirements need to be satisfied. This is primarily due to the fact that the opening through the luer connector is not sealed so that upon disconnection the opening and the fluid passageway are open to the environment which would pose a health hazard to the patient. 
     Another factor which prevents use of luer connection assemblies in administration sets or injection sites is the inability for such a connector to seal against the pressurized fluid found within a set unless that connector is sealed or connected to a mating connector. The opening in a luer fitting will obviously allow such a pressurized fluid to leak. 
     To allow the sealed connections and disconnects to a fluid passageway extending in a set or catheter, on many sets there are one or more injection sites having a solid resilient septum in a housing are placed on the set or catheter. A sharpened needle is used to penetrate the septum to provide a connection to the fluid passageway. Although such connections possess many of the desired characteristics for sealed connections, the sharpened needles poses a needlestick hazard. 
     To combat the needlestick hazard, one embodiment of a needleless systems has been developed which utilizes a resealable septum formed with a slit and compressed within a housing. These needleless systems performed quite well; however, the septum can not be penetrated with a male luer tip and thus a blunt cannula is utilized having a diameter smaller than a male luer tip. If the device to which a connection needs to be made has a luer connector, these blunt cannula are generally attached to the luer fitting. The requirement of the blunt cannula potentially increases the costs of using these types of connectors. 
     Another type of needleless systems use connectors which are constructed to establish a connection directly with the male luer tip whether such luer tip forms a part of a luer slip or a luer lock. However connections which are to be established with a male luer tip in a manner similar to a luer lock connection described above must be capable of fitting within the standard spacing between a luer tip and locking flange and should also meet other standards which have been set out for such connections. 
     Examples of these systems&#39; connectors to establish a connection directly with a male luer tip are shown in U.S. Pat. No. 5,685,866, the disclosure of which is incorporated by reference herein. These connectors appear to all possess shortcomings which hinder widespread acceptance by medical practitioners. In general, all of these devices perform in an inferior manner when measured relative to the desirable qualities for connector devices discussed above and also in comparison to the performance standards of a injection site for a sharpened needle and resilient septum or a blunt cannula and pre-slit resilient septum. 
     For example, several connectors utilize a resilient boot or other seal which is placed within a housing and collapsed by the introduction of a male luer tip. Upon removal of the tip, such collapsing boots must then recover to reseal the connection. Many or these boots stick in the collapsed position which leads to leaking. In addition these moving parts present an interface between the movable boot and housing into which fluid may flow and collect and such collected fluids form a fertile environment for microbial growth, and recessed surfaces and gaps are hard to disinfect. Moreover, the spikes act as flow restrictors and may impart severe turbulence to fluid as it flows through the openings in the spike. Furthermore, after withdrawal of a male luer tip the boots may not recover quickly enough to seal the entrance through the connector and the fluid passageway may be briefly exposed to the environment. 
     One type of such luer tip connectors has a spike within the housing which penetrates a collapsing boot. The spike has openings proximate an end adjacent the boot and form an internal passageway for the flow of fluid which is opened when the spike penetrates the collapsed boot and spreads the slit. Upon recovery, any slit or opening in the boot must reseal. However, the spike design has exhibited unsatisfactory leakage after a number of connects and disconnects which does not provide for extended use of a set or catheter. 
     In addition, these connectors have a multitude of parts which increases manufacturing costs and opportunities for malfunction. These designs also produce a connector having voids which cannot be flushed such that stagnant fluid may collect. Moreover, several of these device have potential passageways from voids within the housing but outside the primary fluid passageway, into the primary fluid passageway which may allow any microbial growth within the housing to enter the fluid passageway. Also the interface between the housing and boot is difficult to swab when the boot is in the uncompressed position. 
     A device described in U.S. Pat. No. 5,616,130, the disclosure of which is incorporated by reference herein, utilizes an elongated cam to spread open a slit in a collapsing boot, and would appear to possess several of the shortcomings of the spike and boot designs described above. 
     It is generally not a problem for the boot connectors to have ends which engage the male tip and locking flange on a standard luer lock. The sealing mechanism is below the end of the luer tip when the tip is engaged to the connector, thus there is a large amount of flexibility in the configuration of the end of the connector housing which engages the male luer lock. 
     To overcome many of these deficiencies, needleless connections which utilize a preslit septum as one of the components were developed. These connectors establish a connection with the penetration of the slit in the septum by the luer tip. One such connector is shown and described in U.S. Pat. No. 5,578,059, the disclosure of which is incorporated by reference herein. In the disclosed valve, a resilient preslit septum is utilized to form an environmental barrier. The septum is sealingly captured or held to the housing by having a lower flange which is pinched between a retainer and housing. It appears that the radially extending portion having a slit is maintained in position by the column strength of an outer axially extending cylindrical portion extending upward from the lower flange. However the septum appears not to be capable of sealing against the pressurized fluid found in a set. Thus the valve uses a second lower check type valve to seal against the pressure. 
     To satisfy ISO dimensional standards and torque removal resistance standards the outer portion of the retainer is formed with a tapered threads so that the connection to a luer lock&#39;s straight thread design is similar to a standard NPTF/NPSI connection. The tapered thread design extends over the end of the housing that engages the threads on a male luer lock. Such a thread design may produce too rapid an increase in engaging force during the connection which may lead to a lock up of the luer lock to the connector. 
     Such a device suffers from several other drawbacks. The valve includes a number of components to make up the housing, the environmental valve and check valve, and this high number of components increases manufacturing costs. In addition, maintaining the septum in position by the column strength of the axially extending portion of the septum forces that portion to have a relatively large thickness. Thus for the septum, the axially extending wall and surrounding housing to fit within the clearance between the luer tip and the locking flange upon penetration of a male luer tip to a desired depth, the housing must be thinned. Such a thinned housing may fracture upon repeated connections and disconnects. 
     A second connector is described in U.S. Pat. No. 5,533,708, the disclosure of which is incorporated by reference herein. This connector also utilizes a preslit septum which is supported on an axially extending column having sufficient thickness to support the septum upon introduction of the male luer tip. The further provide sufficient column strength the axially extending portion is also formed with a specific tapered shape including a thickened lower portion. To seal the slit during introduction and removal of a luer tip, the underside of the pre-slit radial portion of the septum is formed with biasing ribs. 
     This connector also uses a retainer which pinches a lower radial flange to sealingly fix the septum to the housing. Thus the connector includes three separate pieces. In addition the thickened axially extending portion of the septum forces the retainer to be thinned such that to presumably supply strength to the retainer the stated preferred material for the retainer is metal which increases manufacturing costs. In addition it is believed that such valves will not exhibit satisfactory leak pressure after long periods of indwell, likely due to compression set of the septum material due to a perceived high level of compression of the septum material between the tip and retainer. 
     To supply the necessary unscrewing resistance, the retainer is tapered outward proximate the end to establish a frictional engagement with the threads on a male luer lock. 
     Therefore, it is a main object of the invention to overcome those disadvantages of the prior art which prevent widespread acceptance of needleless valves which do not require a blunt cannula. 
     There are other secondary objects, one or more if satisfied may promote market acceptance but satisfaction of each may not be necessary. One object of the present invention is to provide a needless connector fitting which may be actuated by a male luer tip without using a sharpened needle or an adapter such as a blunt cannula or the like. A related object is to provide a connector which may engage a standard luer lock fitting. A further related object is to provide such a connector which may be coupled to a standard male luer lock and complies as much as possible with ISO and ANSI standards for luer connectors 
     Another object of the present invention is to provide a connector which possess sufficient strength to avoid cracking or fracture. 
     It is a further object of the present invention to provide a connector device which utilizes a minimum number of parts and therefore minimizes opportunity for malfunction. 
     It is another object of the present invention to provide a connector device which is capable of providing for a large number of connections and disconnects while maintaining the ability to seal against fluids under pressures typically found in an administration set. A related object is to provide such a connector which is capable of providing a minimum of 100 connects and disconnects without compromising the performance. 
     It is yet a further object of the present invention to provide a connector which upon a disconnection, maintains a leak pressure of 6 psi. constant pressure and 20 psi transient pressure after 4 days of indwell. 
     It is a further object of the present invention to provide a connector which is capable of high speed manufacturing. It is a related object of the present invention to provide a connector which may be manufactured with a very low number of potential defects. 
     It is yet another object of the present invention to provide a connector which minimizes voids which cannot be flushed in which stagnant fluid can collect to form a media for microbial growth. It is a related object of the present invention to provide a connector which forms a sealed fluid path such that a minimum number of microbes enter the fluid path during operation using aseptic techniques. It is a further related object to provide a connector which requires a low priming volume. 
     It is still a further object of the present invention to provide a connector which minimizes or eliminates flow restrictions for the flow of fluid through the connector. In addition it is an object to provide a connector having smooth unbroken surfaces about any inlet to facilitate aseptic techniques. 
     It is yet another object of the present invention to provide a connector which forms a continuous closed system which seals the fluid passageway from the environment during and after insertion of a male luer tip and instantaneously after withdrawal of the luer tip. 
     SUMMARY OF THE INVENTION 
     The above main object is satisfied by connector utilizing a resealable valve having an opening extending through at least a portion of the valve. The valve is resiliently restrained relative to a housing with the valve and housing configured to accept a penetrating member having a tip which penetrates the valve through the opening. 
     One or more of the secondary objects are satisfied by a valve uniquely configured to seal against pressures typically found in fluid passageways which are in fluid communication with the body. Preferably the resealable valve is a septum and the septum and housing are uniquely configured to accept male luer tips. In one embodiment, the septum includes an upper generally disk shaped upper portion covering an opening defined by the housing and a portion extending downward from the upper portion with the valve opening extending through both the upper and lower portion. 
     The upper portion of the valve is resiliently retained relative to the housing by integral attachment with an annular skirt and the skirt may be attached to the interior surface of the housing in a first embodiment and surrounding and attached to an exterior surface of the housing in a second embodiment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a section view of a first embodiment of a needless connector of the present invention; 
     FIG. 2 is a section view of the connector of FIG. 1, shown connected to a male luer tip; 
     FIG. 3 is a section view of a septum forming a part of the connector of FIG. 1; 
     FIG. 3 a  is a bottom plan view of a septum forming a part of the connector of FIG. 1; 
     FIG. 4 is a section view of a second embodiment of a needless connector of the present invention; 
     FIG. 5 is a section view of a septum forming a part of the connector of FIG. 4; 
     FIG. 5 a  is a bottom plan view of a septum forming a part of the connector of FIG. 4; 
     FIG. 6 is a perspective view of the connector of FIG. 4; 
     FIG. 7 is a sectional view of a connector similar to the connector shown in FIG. 4 included as a part of a Y-site; and 
     FIG. 8 is a third embodiment of the needleless connector of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description is not intended to limit the claimed invention to the described embodiments and the disclosed combination of features in the various embodiments might not be absolutely necessary for the inventive solution. 
     Referring to FIG. 1, a first embodiment of a connector device of the present invention is generally indicated at  10 . The connector  10  generally provides multiple fluid connections with a penetrating member  12  (FIG.  2 ). In an example, the connector  10  may be attached to a conduit  14  in fluid communication with the human body. The conduit  14  may be a peripheral catheter  15 , medical tubing or the like and forming a passageway  16  in fluid communication with the body for the flow of fluid to or from a body. The connector  10  may also be attached to other devices such as a vial or vial adapter (not shown) or the like or the connector may be used in lieu of open female luer fittings such as fittings on stopcocks. 
     Referring to FIG. 2, in an example, the penetrating member  12  is preferably a male luer slip or luer lock  13  conforming to ANSI or ISO standards; however, examples of other members, with appropriate modifications to the housing and septum, may include blunt cannula, needles, specially designed connectors or the like. The luer lock  13  includes a luer tip  18  which, in the embodiment shown, is encircled by a locking flange  20  and forms the end of a syringe  24 . Other devices which may utilize a penetrating member  12  include I.V. sets, blood collection and peritoneal dialysis devices and the like. 
     Referring also to FIG. 1, the connector  10  includes a housing  26  and an elastic and resilient resealable member  27 , preferably a septum  28 , disposed at an upper end  30  of the housing to seal an opening  32  defined by the upper end  30 . The septum  28  is operably connected to the housing  26  with a central portion  34  elastically restrained relative to the housing such that the central portion  34  may be stretched downward into the housing as the penetrating member  12  is inserted into the opening. The central portion  34  elastically retracts upon removal of the penetrating member  12 . The housing  26  forms an axially extending passageway  36  which extends downward from the opening  32  and is in fluid communication with the lower passageway  16  defined by the conduit  14 . The resealable member  27  is uniquely configured to seal the opening  32  when the central portion  34  is in the occluding position shown in FIG.  1 . 
     The central portion  34  of the septum  28  has a generally disk shaped upper portion  38  and a lower portion  40  extending axially downward within the passageway. A resealable opening  44 , such as a slit  46  extends downward preferably through both the upper portion  38  and lower portion  40 . It is anticipated that the opening  44  may be formed so that initially the opening may extend only through a portion of one or both of the upper and lower portions  38 ,  40 ; however, extending a penetrating member  12  completely through the septum  28  will force the opening to also extend completely through the septum  28 . Preferably the opening  44  is configured in such a manner such that when the penetrating member  12  extends completely through the septum  28  the upper and lower portions  38 ,  40  are elastically stretched about the penetrating member to seal against leakage through the interface between the penetrating member and the septum. 
     The slit length in the horizontal direction is preferably shorter than one half the circumference of the tip end of the luer tip  18 . 
     As shown in FIGS. 3 and 3 a , in the first embodiment, the lower portion  40  forms a generally rectangular horizontal cross section. Vertically extending sidewalls  48  and end walls  50  are slightly tapered so that the lower portion  40  forms a trapezoidal vertical cross section which facilitates molding and orienting the septum during manufacturing particularly when forming an opening  44 . The opening  44  may extend straight downward or be oriented at an angle relative to the vertical. In addition, the opening  44  may be a slit  46  or may be curved or slightly helically rotated to promote the sealing of the opening. 
     Referring back to FIG. 1, the septum  28  includes an annular skirt  52  which extends downward within the passageway  36  and is attached to the inner surface  54  of the housing  26  to elastically restrain the central portion  34  relative to the housing. The attachment is preferably made by adhesively bonding an outer surface  56  of the skirt  52  to the inner surface  54 . Because displacement of the central portion  34  into the passageway  36  by the luer tip  18  (FIG. 2) applies shear stress to the attachment between the skirt  52  and housing  26 , the septum  28  includes a radial lip  58  which extends over and is attached to an upper edge  60  of the housing. The attachment of the lip  58  and edge  60  at least partially supports the skirt  52  and aids in resisting the shear forces. In the first embodiment the attachment between the lip  58  and edge  60  is by an adhesive bond in the same manner as the attachment of the housing and the skirt  52 . 
     Referring to FIG. 2, to insure universal connectivity, it is preferable that dimensions of luer connecting devices are standardized to ISO standards. For example, the dimensions of the luer tip  18  including the taper are set by the standard. Similarly threads  64  on the inside of the locking flange  20  define a clearance radius Which is set by the standard. As can be appreciated, when the male luer tip  18  extends within the connector  10  and the locking flange  20  extends about the exterior of the connector, the size of the connector and its components are constrained within the spacing between the luer tip and locking flange. Also, according to ISO standards, the male luer tip  18  should be able to penetrate to a desired insertion depth “D” of 0.300 inches which additionally constrains the size of the connector  12  and its components particularly about the upper end  30  of the housing  26  which must fit within the spacing between the luer tip  18  and locking flange  20 . 
     In FIG. 2 the luer tip  18  is shown forcing the septum  28  into an open position. In particular the tip  18  extends through the opening  44  to the desired depth D, establishing fluid communication between a passageway  66  in the tip  18  and the passageway  36 . To minimize any flow restriction, the passageway  36  adjacent the tip  12  is preferably open to the passageway  16  without any secondary valves or other obstructions to fluid flow. The upper portion  38  of the septum  28  pivotally deforms downward, stretches and extends along the annular skirt  52  and the outer surface  68  of tip. In addition the lower portion  40  of the septum  28  extends downward and stretches about the outer surface  68 , and establishes a seal about the tip  18 . 
     Referring briefly back to FIG. 1, upon removal of the tip  18 , the septum  28  resiliently retracts into its closed position. 
     When the tip  18  is inserted into the connector  10  to the desired depth D, there is a limited amount of annular space between the housing  26  and tip into which portions of the septum  28  may be displaced; however, the septum must be configured and sized to seal before, during and after is extension of the penetrating member  12  through the opening  44  to form a closed system. 
     Referring to FIGS. 1 and 2, in several applications in the medical environment, it is highly desirable that connectors be configured to seal against a pressure of 20 psi. As noted above, in various connector designs using a pre-slit septum and blunt cannula penetrating member, as described in U.S. Pat. No. 5,135,489, incorporated by reference herein, the sealing is accomplished by utilizing a thickened septum and a housing to radially compress the septum thereby sealing a slit extending through the septum. When a blunt cannula of small diameter is forced through the slit, the septum is additionally radially compressed which seals about the cannula, and there appears to be little displacement of portions of the septum in an axial direction. 
     However, even if a luer tip  18 , with its much wider diameter relative to the housing opening than the blunt cannula relative to the corresponding housing opening, could be forced through the slit in such a septum, there is little room in the radial direction to provide a receiving space for the displaced mass of the septum. Thus, the necessary insertion force would likely be too much for most medical practitioners. However, it has been found that thinning the septum  28  to allow displacement and accommodation of the septum between the tip and housing while maintaining the same radial compression does not provide the septum with the ability to seal against a pressure found in fluid passageways i.e. “leak pressure”, found during intravenous therapy. Unexpectedly, increasing the radial compression of the thinned septum does not appear to provide a corresponding rate of increase in the leak pressure of the connector  10 . 
     Forming the septum  28  with a thinned upper portion  38  and a downwardly extending lower portion  40  and providing that the opening  44  extends downward through the lower portion  40  in addition to the upper portion  38  greatly increases the leak pressure without requiring a corresponding large increase in septum thickness or compression. Moreover, tests have shown that the length “L1” (FIG. 3) of the lower portion  40  is related to increasing the leak pressure. But, increasing the mass of the septum  28  by increasing the length L1 of the lower portion  40  which must be accommodated within the housing  26  when a luer tip  18  penetrates the resealing member  28 , increases the insert force and could possibly prevent the tip  18  from extending entirely through the opening  44 . 
     The first embodiment&#39;s configuration  6 f a unique combination with a predetermined length L1 of the lower portion  40 , thickness and compression of the upper portion  38  gives the connector  10  a leak pressure of more than 20 p.s.i while presenting an acceptable insert force. Other features of the configuration of the first embodiment is the ability to provide a reseal, after multiple insertions of the luer tip and long periods of luer tip indwell, against a pressure of 6 p.s.i. 
     As an example, in the first embodiment, forming the septum with the upper portion  38  having a thickness of 0.040 inches and a 3.5% radial compression or greater and the lower portion  40  having a length L1 of about 0.080 inches (giving rise to a opening length of 0.125 inches) yields a connector  10  which may accept the luer tip  18  to the desired depth D while maintain a leak pressure in excess of 20 p.s.i. 
     Referring in particular to FIGS. 3 and 3 a , preferably the lower portion  38 ,is formed with a width “W1” of approximately 0.060 inches and a length “L2” of about 0.190 inches. The annular skirt  52  is formed with a thickness of about 0.010 inches. The top surface  70  of the septum  28  is slightly concave to lessen the amount of material being forced into the housing  26  upon insertion of the tip  18  through the opening  44 . It is envisioned that the top surface  70  may be flat or have a convex surface or a combination, also. In addition, the top surface  70  is formed unbroken without crevices or other pockets which facilitates disinfecting of the septum  28  with normal aseptic techniques such as swabbing. Also the septum  28  is formed so that the top surface extends completely over the upper end  30  of the housing to present a visually appealing top surface. 
     Referring back to FIG. 1, to be able to accommodate the standard dimensions of luer fittings, the housing  26  is configured to form a passageway having a diameter “D1” of 0.235 inches. To facilitate insertion of the septum  28  during assembly, the upper end of the passageway  36  is tapered outward so that a slightly larger diameter of 0.250 inches is formed at the opening  32   
     Referring to FIG. 2, as can be appreciated, inserting the tip  18  and compressing the upper portion  38  and possibly the lower portion against the annular skirt  52  should produce a thickness layer of at least 0.050 and 0.040 inches respectively. However, when inserting one embodiment of a penetrating member  12  having standard luer dimensions to a desired depth D of 0.300 inches should only provide an annular clearance of 0.030 inches between the tip and housing  26 . Unexpectedly, the elastic material of the septum elongates upon stretching and deforms into this small clearance dimension, while not exhibiting too low a leak pressure after long periods of indwell due to compression set of the septum  28 . 
     Referring again to FIG. 3 a , the lower portion  40  is formed with rounded comers  74  to form a gap  77  between the lower portion and skirt  52 . The rounding of the corners  74  allows the sidewalls  48  and slit  46  to be as long as possible while still providing the gap between the lower portion  40  and skirt  52 . Attaching the sidewalls  48  to the skirt  52  without providing a gap may contribute to unequal stretching and deformation of the lower portion  40  about the tip  18  during insertion of the tip resulting in leakage. To create the gap  77  the valve member  27  at the gap  77  has a vertical thickness less than the length L1 of the lower portion. Preferably the gap  77  is formed such that the vertical thickness of the valve member  27  at the gap is equal to the thickness of the upper portion  38  of the septum  28 . 
     At the juncture between the central portion  34  and skirt  52  a sharp corner is formed which establishes a hinge point  78 . The hinge point  78  which extends about the housing for the entire circumference of the opening  32  also facilitates the flexing and deformation of the septum  28  during insertion of the tip  18 . 
     In an embodiment, the septum  28  is formed of a elastic, resilient material provided by the West Company of Lionville, Pa. It is anticipated that lubricating the septum  28  should facilitate insertion of the luer tip  18 . Such lubrication may be applied while forming the slit or by other means such as incorporating the lubrication into the septum material or by applying lubricious coatings to the top surface. In a second embodiment, the septum  28  may be formed of a similar material, such as chlorinated polyisoprene produced by Lexington Medical of Rock Hill, S.C. In addition, the slit may be lubricated after assembly of the housing and septum using silicon oil produced by Dow Corning of Midland, Mich. The housing  26  is rigid and preferably formed of DN003 from Eastar of Kingsport, Tenn. 
     Although the housing  26  is shown as forming a luer connection  84  at a lower end, the housing may also be formed as a part of any device into which is it desirable to establish a sealed connection such as the injection arm of a Y-site  86  (FIG.  7 ), as an inlet on a stopcock or manifold (not shown) or the like. In addition the lower end of the housing  26  may be integrally formed with a catheter  15  with a guidewire (not shown) extending upward through the opening  44 . Referring also to FIG. 6, particularly when used as an injection site for a catheter  15 , the exterior of the housing  26  is formed with a number of longitudinally extending indentations  86  which facilitate gripping of the connector  10 . 
     Referring to FIG. 1, to provide for a threaded engagement with a locking flange  20  the upper end  30  of the housing  26  may be formed with a pair of radially extending ears  88  configured to engage the threads  64 . Referring to FIG. 4, alternately threads  90  may be formed on that portion  92  of the housing  26  which will engage the threads  64  on the flange  20 . 
     Preferably the housing  26  is molded as single piece utilizing molds with a large number of molding cavities to facilitate high speed manufacturing operation. Similarly the valve member  27  is preferably formed as a single piece in a high speed molding operation, and the shape of the lower portion  40  is particularly suited to register the valve member  27  in a desired orientation for fashioning an opening  44  therein. 
     Referring to FIGS. 4-6, a second embodiment of the needleless connector of the present invention is generally indicated at  100  and is particularly suited to a large number of connections and disconnects with a standard male luer lock  13  (FIG. 2) without unacceptable leakage. In addition, elements in the second embodiment corresponding to elements in the first embodiment  10  are labeled with the same reference number. 
     The connector  100  includes a housing  102  and an elastic and resilient resealable valve member  104  disposed at an upper end  106  of the housing. The valve member  104  includes the central portion  34  and lower portion  44 ; however the valve member  104 , preferably a septum  105 , also includes an annular skirt portion or restraining skirt  108  which extends about and surrounds an upper portion  110  of the housing  102  adjacent the upper end  106 . Preferably the skirt  108  is bonded to the exterior surface  112  in a specified manner to attach the valve  104  to the housing  102  and elastically restrain the central portion  34  during insertion of the luer tip  18  (FIG.  2 ). 
     Referring to FIGS. 4,  5  and  5   a , it has been found that the manner in which the valve  104  is configured relative to and attached to the housing  102  has an important effect on the ability of the connector  100  to achieve the desired performance standards. Preferably the valve  104  defines a circular annular receiving channel  118  between the central portion  34  and the skirt  108 . The upper end  106  of the housing  102  is received in the channel  118  and bonded to the valve  104  in a desired manner. 
     The central portion  34  is configured such that the upper edge portion  106  applies a 6 to 7% compression on the central portion. To provide adequate reseal, it is desired that the upper portion  40  of the valve  102  form a thickness of 0.60 to 0.50 inches and the lower portion define a length L3 of 0.080 inches. 
     Preferably the lower portion  40  is formed with a width “W2” of approximately 0.060 inches and a length “L4” of about 0.165 inches. The annular skirt  108  is formed with a thickness of about 0.010 inches. The top surface  70  of the septum  28  is slightly concave to lessen the amount of material being forced into the housing  102  upon insertion of the tip  18  (FIG. 2) through the opening  44 . It is envisioned that the top surface  70  may be flat or have a convex surface or a combination, and is adapted to disinfecting techniques such as swabbing. 
     At the interface between the central portion  34  and upper end  106  of the housing  102 , the valve member  104  forms a sharp corner and thereby forms a hinge point  78 . Similar to the first embodiment  10 , lower portion  40  is spaced from the housing to form a gap  77 . 
     It has been found that bonding an upper landing  117  defined by an upper edge  116  to the valve  104  and about the entire circumference of the of the upper edge is important in the ability of the connector  100  to maintain a satisfactory leak pressure and increasingly important to maintain the leak pressure after  100  or more connections and disconnects. The bonding also anchors the septum  28  to the upper edge and prevents a rubbing between the septum  28  and upper edge  116  as the septum is elastically stretched during insertion of the tip  18 . 
     Bonding between the exterior surface  112  and the inner surface of the skirt  108  is also important, but migration of any bonding agent to the interface between the central portion  34  and housing  102  should be minimized. If adhesive collects in the interface about the septum  28  and interior surface  119  cracking of the housing  102  or compression set of the septum  28  with corresponding leakage after long periods of indwell may result. 
     One preferred method of applying bonding agent to the housing  102  such that the upper landing  117  and exterior surface  112  receive such agent while minimizing migration to the interior of the housing is minimized is by placing the housing  102  is a vertical position with the upper edge  116  facing downwards. Bonding agent is applied, preferably by injection, to the exterior surface  112  and gravity causes the agent to flow down and wet the landing  117 . Gravity also hinders any migration of the bonding agent into the interior surface of the housing  102 . A further preferred step includes inserting the upper end portion  110  of the housing  102  into a chamber (not shown) and applying a negative air pressure below the housing  102  such that air flows downward along the housing which also hinders migration of is the bonding agent upwards into the interior of the housing. 
     It has been found that a UV curing adhesive, such as Loctite  3011 ,  3311  and  3301  from Loctite Corporation of Rocky Hill, Conn. may be utilized as a suitable bonding agent for any of the connectors  10 ,  100 ,  200 . The bonding agent should be cured for a sufficiently long period of time. 
     Referring to FIGS. 4 and 6, to provide for threaded engagement with the locking flange  20 , threads  90  extend along a portion of the exterior surface  112 . The upper end  127  of the threads  90  are spaced from the upper edge  116  of the housing  102  to form a surface  124  free of threads, ridges or the like to facilitate the bonding of the skirt  108  to the surface  124 . In a preferred embodiment the surface  124  is also formed with very little if any draft or taper so that the skirt  108  does not creep upward during setting of the bond between the valve  104  and housing  102 . Preferably the skirt  108  extends downward along the housing  124  for a length L5 of about 0.07 to 0.08 inches 
     Referring also to FIG. 2, to minimize shredding of a lower edge  126  of the skirt  108  by the threads  64  on the locking flange  20  during removal of the penetrating member  12  it is important that such threads do not catch on the edge  126 . Thus it is desired that the lower edge  126  be separated from the upper edge  127  of the threads  90  such that the width of a defined gap  128  is less than the width of the threads  64 . 
     To facilitate a releasable engagement of the penetrating member  12  to the connector  100  and to minimize or eliminate any shredding of the skirt  108 , the skirt  108  may be provided with a thickness such that there is minimal interference between the skirt  108  and the inner edge surfaces  64   a  of the threads  64  on the locking flange  20 . However the smaller the diameter defined by the skirt  108  with a given skirt thickness and housing thickness, the smaller the volume which must accommodate both the penetrating member  12  and valve  104  upon insertion of the member  12 . 
     It has been found that providing a housing  102  with the upper portion  110  having a external diameter of 0.25 inches and defining an opening  144  with a diameter of 0.22 is desired to provide the proper clearance between the skirt  108  and locking flange  20  of an ISO standard luer connection and yet also provide a housing with sufficient wall strength to resist fracture and provide sufficient space for the displaced septum  28  and luer tip  18  when the luer tip is inserted into the housing  102 . 
     Referring to FIG. 4 in conjunction with FIG. 2, the frustoconical shape of an ISO standard luer tip defines a diameter ranging from 0.155 in. to 0.175 inches. Thus when an ISO standard luer tip  18  is inserted the desired insertion distance D, it would be expected that the tip and housing  102  define a clearance therebetween of 0.031 to 0.021 inches. What is surprising is that upon insertion of a male luer tip  18 , the valve  102 , having an upper portion  38  with a thickness of about 0.055 inches extends about the luer tip and is compressed within the smaller clearance without requiring an unacceptable insertion force. In addition, although one may expect some compression set of the septum  28  due to the compression between the tip and housing which would lead to leakage after long indwell problems, it has been unexpectedly found that the valve member  104  maintains an adequate leak pressure after long periods of indwell. 
     As illustrated in FIG. 7, the displacement and compression of the septum  28  into the space between the tip  18  and housing  102  during insertion of the tip substantially fills the space between the lower portion  40  and housing  102  for a depth corresponding to the majority of the extended length of the lower portion about the tip  18 . The compressed septum  28  displaces or flushes any fluid that has collected in this space. The injection of the fluid from the tip  18  into the interior of the housing  102  flushes any remaining spaces within the housing. Thus stagnant pockets of fluid are avoided. The filling of the passageway  36  with the tip  18  and displaced septum  104  also reduces priming volume to a low level. 
     Referring to FIG. 7, an embodiment of the needleless connector of the present invention is generally illustrated at  130 . In particular the connector  130  is shown as forming part of a Y-site connection assembly  86 . As is generally known in the field, Y-site connection assemblies  86  are particularly suited for adding supplemental fluid to a flow of fluid along a primary flow path  132  extending from an upper or entry section  134  of attached tubing, through the Y-site assembly  86  and out along a lower or exit section  136  of attached tubing. 
     The needless connector  130  is shown as generally corresponding to the second embodiment of the needless connector  100 , however, the resealable valve member  140  and housing  138  proximate the valve member may be shaped to correspond to the housing and valve member of either the first embodiment 10, second embodiment 100 or the later described embodiment 200. 
     As can be appreciated, once the luer tip  18  penetrates the valve member  140 , the passageway  66  in the tip is placed directly in fluid communication with that portion of the primary flow path  132  extending into the exit section  136  without any intermediate valves so any flow restriction is reduced. 
     Referring to FIG. 8, a third embodiment of the needless connector of the present invention which is preferred, is generally indicated at  200 . The third embodiment 200 has a housing  202  and includes the resealable valve member  104  described in relation to the second embodiment  100 . The housing  202  is similar to the first embodiment 100 except that a housing portion  204  below the gap  128  has been altered so that connector  200  provides a higher removal resistance torque. Elements in the third embodiment 100 corresponding to elements in the first or second embodiment 10 are labeled with the same reference number. 
     In particular, the housing  202  includes the upper portion  110  having the surface  124  of a generally constant outside diameter over which the skirt  108  extends. A middle portion  206  extends downward from the, upper portion  116  and a lower portion  208  extends downward from the middle portion. The lower portion  208  preferably defines a generally constant diameter greater than the diameter defined by the upper portion  116 . The middle portion  206  is formed to provide a transition from the upper portion  116  to the relatively wider lower portion  208 . Preferably the middle portion  206  is frustoconically shaped. 
     Referring to FIGS. 2 and 8, the housing  202  defines a set of double start threads  210  which extend downward along the housing about the middle portion  206  and lower portion  208 . In the preferred configuration, the threads  210  define a constant major diameter as the threads extend along the lower and middle portions such that the height of the threads decreases as the threads move downward along the middle portion. However the diameter defined by the lower portion  208  is greater than the minor diameter defined by the internal threads  64  on the locking flange  20  such that there is a sliding frictional engagement between the threads  64  and middle and lower portions  206 ,  208 . The frictional engagement allows the connector  200  to provide an acceptable removal resistance torque for an attached luer lock when the tip  18  has penetrated to the desired insertion depth D. 
     Utilization of an upper portion with a surrounding skirt  108  defining a diameter approximately that of the standard major diameter of threads  64 , a frustoconical middle portion  206  defining a diameter increasing from a diameter less than the diameter defined by the skirt  108  to the diameter of the lower portion  208  and the lower portion defining a diameter greater than the minor diameter of the internal threads  64  imparts a feel to the user similar to connecting to a standard female luer connection. 
     When the user first inserts the locking flange  20  over the connector  200 , slipping the flange over the upper portion  116  and surrounding skirt  108  promotes centering of the luer tip  18  relative to the connector  200  and minimizes the opportunity for cross threading. As the tip and flange  20  continue over the connector  200 , the threads  64  then engage the threads  210  and the connector  200  must then be rotated relative to the flange  20  to threadingly engage the flange  20  to the connector  200 . 
     During rotation, the tip  18  extends through the opening  44  and rubs against the valve  104  however such contact supplies very little resistance to turning. The threads  64  engage the middle portion  206  and a sliding frictional engagement begins and the required torque to advance or unthread slowly increases as the tip is rotatably advanced. The threads  64  then engage the lower portion  208  having a constant diameter which slows down the rate or increase in the removal torque before an unacceptable removal torque is achieved which may cause the locking flange  20  to lock up on the connector. 
     In addition male luer locks  13  may be made of many different types of materials which range in stiffness. It is important that the connection of the connector  200  to the luer lock not place such a stress on the locking flange  20  which may fracture the flange. The use of the lower portion  208  with a constant diameter also accommodates luer locks of various materials while preventing overstressing of the locking flange  20 . 
     Thus three example embodiments of a needleless connector have been described. It is believed that the embodiments provide features which solve many of the drawbacks which have hindered widespread acceptance of such needleless connectors relative to the market acceptance of the type of connectors which must be pierced with a sharp needle or blunt cannula. 
     It will be understood that the embodiments of the present invention which have been described are illustrative of some of the applications of the principles of the present invention. Various modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.