Abstract:
A collapsible valve comprising a first portion with at least one dimple in a side thereof, and a second portion, the second portion being narrower than the first portion and arranged along an axial dimension of the first portion, the second portion including a cut therein.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a continuation application of, and claims priority to, U.S. patent application Ser. No. 12/512,719, entitled “COLLAPSIBLE VALVE,” filed on Jul. 30, 2009, the entire contents of which are incorporated by reference herein for all purposes. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates, generally, to fluid flow devices and, more specifically, to valves for use in medical devices. 
     BACKGROUND OF THE INVENTION 
     Needleless access devices allow a healthcare professional to, e.g., replace/add IV bags, and/or access an IV line without having to use a needle.  FIG. 1  is a cut-away view of a current needleless access device  100 . Needleless access device  100  includes female luer fitting  101 , male luer fitting  102 , and valve  103 . When in use, male luer fitting  102  is connected to, e.g., a catheter or to a female luer, and female luer fitting  101  is connected to a fluid reservoir. Female luer fitting  101  is connected to the fluid reservoir via a second male luer fitting (not shown) that includes a hollow member inserted through the top of female luer fitting  101 , collapsing valve  103  down into volume  104  to break the seal and create a fluid flow path. The hollow member of the second male luer fitting delivers the fluid, which flows around valve  103  into channels (not shown) in male luer fitting  102  and into the catheter or female luer. 
     Inside valve  103  is a gap (or septum, not shown), that is filled with air. Device  100  is a positive displacement device, so that when a new connection is made at female luer fitting  101 , device  100  pulls fluid in from the male side of the valve (i.e., the side proximate male luer fitting  102 ). When a disconnection is made at female luer fitting  101 , device  100  pushes fluid in from the female side (i.e., the side proximate the top of female luer fitting  101 . The advantage of positive displacement is that when a disconnection is made, device  100  expels fluid out of the male luer fitting  102  and effectively flushing the catheter. By contrast, many devices on the market today have negative displacement, so that when a syringe is disconnected, such device pulls a little bit of fluid from the male luer side, which, if a catheter is being used, means that blood is pulled into the catheter lumen. Blood that is left in a catheter lumen may clot and cause health problems for the patient. 
     An additional feature of device  100  is that when the female end is accessed by a male luer (not shown), valve  103  is elastic so that it can bend out of the way to allow flow and then return to its original shape after a disconnection is made at the female end. Thus, device  100  re-seals itself and forms a flat surface that can be disinfected at the top surface  110  using an alcohol swab. By contrast, many devices on the market use plastic valves that cannot flex to move out of the way to allow flow, thus requiring the use of valves that are slanted or incorporating features at the top, making swabbing difficult. 
     Device  100  has a symmetrical valve body providing symmetrical wall strength, as well as weakness points on both sides by virtue of duckbills  105 . Furthermore, device  100  includes uniform wall thickness in the valve body, even at and around duckbills  105 . The contact area between a luer and the top surface  110  of valve  103  and the type of luer motion will dictate the form of collapse of the valve body. Device  100  provides good performance, but could benefit from enhanced repeatability and controllability of collapse. 
     BRIEF SUMMARY OF THE INVENTION 
     Various embodiments of the invention are directed to valves, and to needleless access devices that use collapsible valves, which include a cut and at least one dimple to cause specific collapsing valve behavior. In one specific example, a cut is placed on a top portion of a valve, the top portion being narrower in diameter than a bottom portion and forming the top seal of a needleless access device. The bottom portion is substantially cylindrical, forming a septum, and including at least one dimple thereon. The dimple is angularly offset from the cut by approximately ninety degrees, enough so that a load point on the top surface of the valve is shifted away from the cut to delay the collapse of the cut and result in less forward fall of the top portion when the cut collapses. A method according to one embodiment is related to processes for manufacture of needleless access devices. Another embodiment is directed to a needleless access device that includes a collapsible valve. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a cut-away view of a current needleless access device; 
         FIGS. 2A and 2B  are cut-away views showing an exemplary needleless access device adapted according to one embodiment of the invention; 
         FIGS. 3A-C  show views of a valve by itself; 
         FIGS. 4A and 4B  show views ninety degrees from those of  FIGS. 3A and 3B ; 
         FIG. 5  is an illustration of an exemplary needleless access device with a syringe inserted therein and collapsing an exemplary valve; 
         FIGS. 6A-6D  illustrate the behavior of an exemplary valve, as pressure is applied by a syringe, but before collapse, according to embodiments of the invention; 
         FIGS. 7A-7D  illustrate behavior of an exemplary valve as pressure is applied by a syringe, but before collapse, according to embodiments of the invention; 
         FIG. 8  is an illustration of one scenario of use of an exemplary valve; and 
         FIGS. 9A-9C  show three examples of a wide variety of cuts that can be applied to some embodiments of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 2A and 2B  are cut-away views showing exemplary needleless access device  200  adapted according to one embodiment of the invention. The view in  FIG. 2B  is rotated ninety degrees from that shown in  FIG. 2A . 
     Device  200  includes female luer fitting  201 , male luer fitting  202 , and valve  210 . Valve  210  includes cut  211 , which in this example, is referred to as a “smiley cut.” Valve  210  also includes dimples  212  and  213  on the outside of its lower portion and placed with axial and angular offsets from each other so that the body of valve  210  is not symmetrical. While cut  211  is referred to as a cut, it can be manufactured using any of a variety of techniques, including molding so that a cut is not actually made. An example of a material that may be used for male and female luer fittings  201  and  202  is polycarbonate, and an example of a material that may be used for valve  210  is silicone, though any of a variety of suitable materials may also be used in various embodiments. 
     Device  200  provides for positive displacement and self sealing, similar to the device shown in  FIG. 1 . Male luer fitting  202  at the bottom, connects to a catheter or other medical device (not shown) that is connected to the body of the patient. A syringe (not shown) mates with female luer fitting  201  to collapse valve  210  into the cavity defined between male and female luer fittings  201  and  202 . Fluid flow goes from the top of device  200 , around valve  210 , and through channels  230 ,  240  to middle channel  250  of male luer fitting  202 . Valves  260  and  270  allow air to enter and escape septum  215  of valve  210 . 
     When closed, valve  210  provides two seals. The first seal is at the top surface  280  of device  200 . The second seal is at shoulder  290 . As explained in more detail with respect to  FIG. 5 , insertion of a syringe at female luer fitting  201  collapses valve  210 , thereby breaking the seals. Valve  210  acts as a spring, so that when it is pushed it down, it collapses, and when the force is removed, it returns to its shape thereby resealing. Generally, the thicker the wall of valve  210 , the more spring force, and the thinner the wall, the less spring force. Therefore, wall thickness affects characteristics, such as ease of syringe insertion and displacement. In one particular example where valve  210  is approximately two centimeters in length, a wall thickness within the range of 0.030 and 0.038 inches provides acceptable displacement, sealing, and ease of use. Of course, at dimples  212  and  213  the wall thickness is less, as can be seen especially well at  FIG. 3A . 
     In one example, device  200  is manufactured by separately molding valve  210  and male and female luer fittings  201  and  202 . Valve  210  is then placed in the cavity that is formed by male and female luer fittings  201  and  202 . Male and female luer fittings  201  and  202  are positioned and welded. Device  200  is then sterilized and packaged. Other methods for manufacturing are possible, e.g., by gluing rather than welding male and female luers  201  and  202 , and are within the scope of embodiments. 
       FIGS. 3A-C  show views of valve  210  by itself.  FIG. 3B  shows a side view,  FIG. 3A  shows a cut-away view, and  FIG. 3C  shows a bottom view of valve  210 . As can be seen, both the top portion and the bottom portion of valve  210  are annular (in this case, substantially cylindrically shaped), where the top portion includes smiley cut  211 , and the bottom portion includes dimples  212  and  213 . The bottom portion of valve  210  is substantially hollow, defining septum  215 .  FIGS. 4A and 4B  show views ninety degrees from those of  FIGS. 3A and 3B . 
       FIG. 5  is an illustration of exemplary device  200  with exemplary syringe  510  inserted therein and collapsing valve  210 . Smiley cut  211  collapses, tilting its top surface  216  to let fluid flow out of syringe  510 . The lower portion of valve  210  also collapses, aided by dimples  212  and  213 , which act as two weak points, placed to cause the lower portion to collapse before smiley cut  211  collapses. Arrows are added to  FIG. 5  to illustrate a path of fluid as it flows through syringe  510 , around valve  210 , and out of male luer  202 . 
     In the embodiments shown in  FIGS. 2-5 , smiley cut  211  is placed relative to dimples  212  and  213  to facilitate specific collapsing behavior.  FIGS. 6A-6D  illustrate the behavior of valve  210 , as pressure is applied by syringe  510 , but before collapse. In the embodiment of  FIGS. 2-6 , dimple  213  is placed ninety degrees clockwise from smiley cut  211 , which places load point  610  counterclockwise to smiley cut  211  (wherein clockwise and counterclockwise refer to the orientation shown in  FIGS. 2-6 , where the valve  210  is shown with smiley cut  211  above the dimples). The placement of load point  610  is notable because a male luer fitting (not shown) associated with syringe  510  has a thread to connect to female luer fitting  201 , thereby rotating syringe  510  as it is inserted (and in turn, putting rotational pressure on valve  210 ). As dimple  213  begins to collapse, pressure point  610  appears ninety degrees from smiley cut  211 , where the side of the top portion of valve  210  is stronger than it is directly above smiley cut  211 . In this embodiment, smiley cut  211  collapses later than it would in a scenario where load point  610  is placed directly over smiley cut  211 . 
     By contrast,  FIGS. 7A-7D  illustrate behavior of valve  710  as pressure is applied by syringe  510 , but before collapse, according to embodiments of the invention. In valve  710 , smiley cut  211  is 180 degrees from dimple  213  and directly above dimple  212 . Such placement of dimples  212 ,  213  and smiley cut  211  causes pressure point  720  to be directly above smiley cut  211 , thereby causing smiley cut  211  to collapse sooner than it does in the scenario illustrated in  FIGS. 6A-6D . 
     In many uses, both valve  210  and valve  710  are acceptable alternatives. However, in scenarios wherein syringe  510  includes a counterbore, early collapse of smiley cut  211  may cause the top of valve  710  to fall forward and become lodged in the counterbore, thereby somewhat impeding the flow of fluid. Such a scenario is shown in  FIG. 8 , where the top of valve  710  is lodged in counterbore  820  of syringe  810 . By contrast, valve  210  delays the collapse of smiley cut  211 , providing a more vertical collapse of smiley cut  211  and avoiding blockage of syringe counterbores. Thus, in scenarios where a syringe includes a counterbore, valve  210  can be employed successfully. Both valve  210  and valve  710  can be successfully employed in applications using a syringe, such as that shown in  FIGS. 5-7 . Various embodiments can use any angular displacement of a dimple relative to a cut, with valve  210  and valve  710  illustrating two examples. 
     While valves  210  and  710  are shown with two dimples each, various embodiments are not so limited. For instance, more dimples may be added, and some embodiments may include only one dimple. Furthermore, embodiments are not limited to the use of smiley cuts, as other shaped cuts may be employed. For instance,  FIGS. 9A-9C  show V-cut  910 , U-cut  920 , and “seagull” cut  930 , which are but three examples of a wide variety of cuts that can be applied to embodiments. 
     As shown above, various embodiments include valves with flat tops that facilitate flow around, rather than through, said valves. Such features provide advantages over embodiments that use hard plastic, do not have flat tops, and/or allow flow through, rather than around valves. For instance, valves  210  and  710  of the embodiments described above provide positive displacement and are self-flushed, thereby providing better hygiene that negative displacement devices. Furthermore, the flat top surfaces of valves  210  and  710  can provide for better swabability than do devices with slanted or grooved tops, once again providing better hygienic qualities. Additionally, the dimples and cuts shown in the embodiments above provide for somewhat predictable collapse of the valves, and (especially in the case of valve  210 ) applicability to any of a variety of syringes. 
     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.