Abstract:
A method of placing a catheter into a patient while preventing disadvantageous escape of fluid from the patient comprises providing a catheter secured to a valve hosing. The catheter has a proximal end, a distal end and an interior lumen. The valve housing has a first port, a second port, and a fluid path running between the first and second ports. The catheter and the valve housing have a hollow needle extending therethrough. The method further comprises piercing the patient&#39;s skin, thereby inserting the catheter into the patient. The method further comprises holding the catheter and valve housing in place while removing the hollow needle through the catheter and valve housing. The hollow needle passes through the first and second ports of the valve housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 11/387,469, filed Mar. 23, 2006, which is hereby incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates generally to catheters used in medical treatments, and specifically to an over-the-needle catheter with a hemostasis valve that restricts blood flow in the absence of an attached medical component. 
       DESCRIPTION OF THE RELATED ART 
       [0003]    In the medical field it is often necessary to insert a catheter into a portion of the human body to withdraw fluids from, or deliver fluids to, the patient undergoing treatment. For example, one method of catheter insertion involves an “over-the-needle” catheter. In an over-the-needle catheter, a needle is positioned within a catheter lumen which is configured to fit snugly around the needle. After an over-the-needle catheter is inserted into the patient&#39;s vascular system, the needle is withdrawn, leaving the catheter in place. 
         [0004]    One significant problem with this method of implanting a catheter in the bloodstream of a patient is the tendency of blood to flow from the bloodstream through the catheter upon removal of the needle, stylet, trocar, or guidewire used in the procedure of piercing the body and placing of the catheter therein. Once the passageway between the bloodstream and the catheter opening is opened, blood tends to flow out of the body. Additionally, removal of a medical component (such as an intravenous fluid line) from the proximal end of an inserted catheter permits blood to flow from the patient out of the catheter. Such blood flow out of the patient is an undesirable result as it well-recognized in the industry. It is therefore desirable to have a device which seals an over-the-needle catheter from fluid flow in one or both directions upon removal of the needle, stylet, trocar, or guidewire. Such devices are commonly referred to as “hemostasis valves.” 
         [0005]    Many solutions to the above-stated problem have been suggested. For example, U.S. Pat. No. 5,405,323 teaches a catheter check valve assembly which incorporates a duckbill valve and a manually operable separator. U.S. Pat. No. 4,449,693 discloses a valve of resilient tubing into which a stopper having an oval sealing ring is placed. U.S. Pat. No. 5,073,168 teaches a y-adapter with a check valve formed from conformable sheets. U.S. Pat. Nos. 5,112,301; 5,156,600 and 5,167,636 also teach other types of catheter check valves and hemostasis valves. 
         [0006]    Some existing bi-directional hemostasis valves rely on a differential fluid pressure across a membrane to seal the catheter from fluid flow. This will unfortunately not solve the problem of accidentally disconnected medical component connections, as blood pressure is typically higher than atmospheric air pressure, thus causing blood to leak from such a valve in the absence of a second fluid. Other hemostasis valves described in the above-mentioned patents generally share the disadvantage that they require conscious action of the operator to fully close the valve and seal the cannula from allowing blood to flow out of a patient. This extra step can be forgotten, thus leaving the catheter open to unwanted fluid flow. 
         [0007]    Therefore, it is desirable to have a hemostasis valve for an over-the-needle catheter which will always be closed when the medical component is removed, and which requires no extra movement of parts and no extra user actions to further seal the catheter. It is also desirable to have a hemostasis value that is inexpensive to manufacture, that is simple to operate, and that presents a flat surface to facilitate, for example, effective disinfection. 
       SUMMARY OF THE INVENTION 
       [0008]    According to one aspect of the present invention, a method of placing a catheter into a patient while preventing disadvantageous escape of fluid from the patient comprises providing a catheter secured to a valve housing. The catheter has a proximal end, a distal end and an interior lumen. The valve housing has a first port, a second port, and a fluid path running between the first and second ports. The catheter and the valve housing have a hollow needle extending therethrough. The method further comprises piercing the patient&#39;s skin, thereby inserting the catheter into the patient. The method further comprises holding the catheter and valve housing in place while removing the hollow needle through the catheter and valve housing. The hollow needle passes through the first and second ports of the valve housing. 
         [0009]    According to another aspect of the present invention, a method of opening a hemostasis valve comprises providing a hemostasis valve housing. The hemostasis valve housing has a first port, a second port, and a fluid path running between the first and second ports. The method further comprises positioning an occlusion assembly within the hemostasis valve housing. The occlusion assembly has a pivot pin in contact with first and second occlusion arms. The occlusion assembly is movable between a closed position and an open position. In the closed position, the first and second occlusion arms contact each other, causing the hemostasis valve housing first port to be occluded. In the open position, the first and second occlusion arms do not contact each other, allowing fluid flow through the hemostasis valve housing first port. The method further comprises moving the occlusion assembly between the closed position and the open position by sliding the occlusion arms along opposite sides of the pivot pin. 
         [0010]    According to another aspect of the present invention, a hemostasis valve comprises a valve housing having a first port, a second port opposite the first port, and a fluid path running between the first and second ports. The hemostasis valve further comprises an occlusion assembly disposed within the hemostasis valve. The occlusion assembly has a pivot pin in contact with first and second occlusion arms, such that the first and second occlusion arms contact opposite sides of the pivot pin. The occlusion assembly is movable between a closed position and an open position. In the closed position, the first and second occlusion arms contact each other, causing the valve housing first port to be occluded. In the open position, the first and second occlusion arms do not contact each other, allowing fluid flow through the valve housing first port. 
         [0011]    According to another aspect of the present invention, a hemostasis valve comprises a valve housing having a first port, a second port opposite the first port, and a fluid path running between the first and second ports. The hemostasis valve further comprises means for opening the fluid path when a medical component is attached to one of the valve housing ports, and occluding the fluid path when the medical component is removed from the valve housing port. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    Having thus summarized the general nature of the invention and its essential features and advantages, certain preferred embodiments and modifications thereof will become apparent to those skilled in the art from the detailed description herein having reference to the figures that follow, of which: 
           [0013]      FIG. 1  is a side sectional view of one embodiment of a hemostasis valve in the closed position. 
           [0014]      FIG. 2  is a side sectional view of the hemostasis valve of  FIG. 1  in the open position. 
           [0015]      FIG. 3  is a perspective side sectional view of the hemostasis valve of  FIG. 1  in the closed position. 
           [0016]      FIG. 4  is a side sectional view along cross-section  4 - 4  of the hemostasis valve of  FIG. 1  in the closed position. 
           [0017]      FIG. 5  is a side sectional view of one embodiment of a hemostasis valve configured for use with an over-the-needle catheter. 
           [0018]      FIG. 6  is an exploded side view of a hemostasis valve having an occluder control arm. 
           [0019]      FIG. 7  is an exploded perspective view of the hemostasis valve of  FIG. 6 . 
           [0020]      FIG. 8  is another exploded perspective view of the hemostasis valve of  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]      FIGS. 1 through 4  illustrate one embodiment of a hemostasis valve  100  for use with an over-the-needle catheter having features and advantages of the present invention. The hemostasis valve  100  comprises a valve housing  110  configured to allow fluid to flow along fluid path  116  between a first port  112  and a second port  114 . The first port  112  is fitted to allow a medical component  102  (illustrated in  FIG. 2 ) to be removably attached thereto, and the second port  114  is fitted to allow a catheter hub (not shown) to be secured thereto. The hemostasis valve  100  further comprises an occluder  120  positioned within the valve housing  110  that is movable between an open position  122  (illustrated in  FIG. 2 ) and a closed position  124  (illustrated in  FIG. 1 ). In such embodiments, when the occluder  120  is in the open position  122 , fluid may flow along fluid path  116  between the first port  112  and the second port  114 . When the occluder  120  is towards the closed position  124 , fluid path  116  is occluded, thereby preventing the flow of fluid between the first port  112  and the second port  114 . In such embodiments, the occluder  120  is biased in the closed position  124 , such that when the medical component  102  is attached to the first port  112 , a force  126  is applied to the occluder  120 , which causes the occluder to move to the open position  122  and thereby permits fluid flow through the valve housing  110 . Likewise, when the medical component  102  is removed from the first port  112 , the occluder  120  returns to the closed position  124  and thereby prevents fluid flow through the valve housing  110 . 
         [0022]    In certain embodiments, the valve housing  110  is preferably substantially cylindrical and hollow, thereby providing a fluid path  116  along a central axis  130  between the first port  112  and the second port  114 . The fluid path  116  not only allows fluid to pass between the first port  112  and the second port  114 , but it also allows a needle (not shown) to be passed through the entire valve housing  110 . Such passage of a needle allows the hemostasis valve  100  disclosed herein to be advantageously used in connection with an over-the-needle catheter. 
         [0023]    As illustrated in  FIG. 2 , the first port  112  of the valve housing  110  is fitted to be removably attached to a medical component  102 . In certain embodiments, the attachment mechanism is by means of a threading mechanism  118  (for example, a screw-on screw-off mechanism such as a luer lock), although in other embodiments, the removable attachment mechanism may comprise a snap-fit configuration, a latching configuration, or any other removable attachment mechanism. Likewise, the second port  114  of the valve housing is fitted to securely attach to a catheter hub (not shown) by means of a threading mechanism  118  or any other attachment mechanism. 
         [0024]    In certain embodiments, the valve housing  110  is preferably comprised of a molded biocompatible polycarbonate material, although in other embodiments, the valve housing  110  is comprised of any other material suitable for use in medical applications, and capable of providing the features and advantages of the present invention. 
         [0025]    As illustrated in  FIGS. 1 through 4 , in certain embodiments, the occluder  120  further comprises first and second occluder shafts  154 ,  156  which connect first and second occluder proximal portions  150 ,  152  with occluder distal ring  158 . The occluder  120  is preferably comprised of a flexible biocompatible polycarbonate material, such as acrylonitrile-butadiene-styrene (ABS) or polyvinyl chloride (PVC), although other materials, including silicon-based materials, may also be used. In particular, the material comprising the occluder  120  is preferably sufficiently flexible such that when the occluder  120  is in the closed position  124 , the hollow needle  106  (illustrated in  FIG. 5 ) can pass between the first and second occluder proximal portions  150 ,  152  without allowing fluid to leak from the first port  112 . In a preferred embodiment, the first and second occluder proximal portions  150 ,  152  further comprise a seal cap  159  comprising a silicone or rubber material. Seal cap  159  is configured to facilitate the hollow needle  106  passing through the first and second occluder proximal portions  150 ,  152  without allowing fluid to leak from the first port  112 . Seal cap  159  preferably comprises a material different than the material comprising the occluder proximal portions  150 ,  152 . 
         [0026]    In such embodiments, the first and second occluder proximal portions  150 ,  152  are shaped to fit together to occlude the first port  112  completely. For example, in embodiments wherein the first port  112  has a circular cross-sectional shape of diameter d, the first and second occluder proximal portions  150 ,  152  can each be in the shape of a half-circle of diameter d. Thus, in such embodiments, when the occluder  120  is in the closed position  124  (that is, when the proximal occluder ends  134  are positioned within the first port  112 ), the first port  112  is completely occluded, thereby preventing the flow of fluid therethrough. 
         [0027]    In such embodiments, the first and second occluder shafts  154 ,  156  have a rectangular cross section, although in alternative embodiments other cross sectional shapes, such as circles, ovals, or other polygons may be used. Notably, the first and second occluder shafts  154 ,  156  do not extend around the circumference of the valve housing  110 , unlike the occluder distal portion  158  and the occluder proximal portions  150 ,  152 . This configuration is illustrated in  FIG. 1 , which illustrates that the occluder proximal portions  150 ,  152  and the occluder distal portion  158  extend to the interior wall of the valve housing  110 . In contrast,  FIG. 4  illustrates that the first shaft  154  (like the second occluder shaft  156 , which is not shown in  FIG. 4 ) is a structural arm that functions to transmit forces between the occluder distal portion  158  and the occluder proximal portions  150 ,  152 . 
         [0028]    The occluder distal ring  158  is preferably a substantially cylindrical ring configured to slide along the interior walls of the valve housing  110  in a direction indicated by arrows  160 . As described above, the first and second occluder shafts  154 ,  156  are configured to transmit a force  126  applied to the first and second occluder proximal portions  150 ,  152  to the occluder distal ring  158 , such that a force  126  applied to the first and second occluder proximal portions  150 ,  152  causes the occluder  120  to move distally in a direction indicated by arrows  160 . 
         [0029]    As illustrated in  FIGS. 1  though  4 , in certain embodiments, seal guide pins  140  (also referred to as “pivot pins” or “guide pins”) are positioned between the first and second occluder shafts  154 ,  156 . In such embodiments, the seal guide pins  140  are securely attached to the inner walls of the valve housing  110 , and gap  142  (as illustrated in  FIG. 4 ) exists between seal guide pins  140  to allow a needle to pass through the center of the valve housing  110 .  FIG. 5  illustrates one embodiment of seal guide pins  140  and occluder  120  positioned within valve housing  110 . In such embodiments, the seal guide pins  140  are preferably comprised of a rigid material such as stainless steel, although in other embodiments the seal guide pins  140  are comprised of any other rigid, biocompatible material suitable for use in medical applications. 
         [0030]    As explained above, the occluder distal ring  158  is configured to slide along the inner walls of the valve housing  110  in a direction indicated by arrows  160 . As the occluder distal ring  158  slides toward the second port  114 , the first and second occluder proximal portions  150 ,  152  move distally from the first port  112  and are pivoted radially away from the central axis  130  (illustrated in  FIG. 2 ) due to the placement of the seal guide pins  140 . Specifically, as the occluder distal ring  158  slides towards the second port  114 , the first and second occluder shafts  154 ,  156  slide/roll along opposite sides of the seal guide pins  140 . The seal guide pins  140  act as a fixed control surface pivot point, forcing the first and second occluder shafts  154 ,  156  to move radially away from the central axis  130 , thereby opening fluid path  116 . In such a configuration (that is, when the occluder  120  is in the open position  122  as illustrated in  FIG. 2 ), fluid may pass between the first port  112  and the second port  114  along fluid path  116  between the guide pins  140 . Preferably, the first and second occluder shafts  154 ,  156  and the seal guide pins  140  are manufactured of materials capable of sliding with respect to each other with low frictional losses. The first and second occluder shafts  154 ,  156  and the seal guide pins  140  may also be lubricated. 
         [0031]    Likewise, as the occluder distal ring  158  slides toward the first port  112 , the first and second occluder proximal portions  150 ,  152  are guided into the first port  112  due to the funnel neck portion  144  of the valve housing  110 . When the occluder  120  is in the closed position  124  as illustrated in  FIG. 1 , the first port  112  is occluded, thereby precluding fluid flow between the first port  112  and the second port  114  along fluid path  116 . 
         [0032]    The occluder  120 , which is movable between the open position  122  and the closed position  124 , is preferably biased towards the closed position  124 . As illustrated in  FIGS. 1 through 4 , the occluder  120  is biased in closed position  124  due to the presence of spring  170  positioned within the valve housing  110 . Thus, when a force  126  is applied to the first and second occluder proximal portions  150 ,  152 , the spring  170  compresses and the occluder  120  moves to the open position  122 , as illustrated in  FIG. 2 . Similarly, when the force  126  is removed from the first and second occluder proximal portions  150 ,  152 , the spring  170  and the funnel neck portion  144  of the body  110  causes the occluder  120  to return to the closed position  124 , as illustrated in  FIG. 1 . In such embodiments, the spring  170  is preferably comprised of stainless steel, although in other embodiments the spring  170  is comprised of any other biocompatible material suitable for use as a spring in medical applications, and which will not lose resiliency after repeated uses. 
         [0033]    In a preferred embodiment, illustrated in  FIG. 2 , medical component  102  is removably attached to the valve housing  110  via threading mechanism  118 . In such embodiments, as medical component  102  is threaded onto the valve housing  110 , actuator element  104  applies a force  126  to the first and second occluder proximal portions  150 ,  152 , causing the occluder  120  to move to the open position  122 , and permitting fluid flow along fluid path  116 . Likewise, when medical component  102  is removed from the valve housing  110 , the spring  170  causes the occluder  120  to return to the closed position  124 , wherein the first and second occluder proximal portions  150 ,  152  occlude fluid flow along fluid path  116 . One of ordinary skill in the art will recognize that the medical component  102  can be attached to the valve housing a variety of attachment means, such as a conventional luer lock or by use of friction if a tapered syringe luer fitting is used. Suitable medical components  102  include, but are not limited to, syringes, feeding or hydrating bags, intravenous drip bags, or other tubing, conduits or catheters. 
         [0034]    In other embodiments, as illustrated in  FIG. 5 , the hemostasis valve  100  is available prepackaged with an over-the-needle catheter  132  secured to the second port  114 . The over-the-needle catheter  132  can be attached to the second port  114  by a wide variety of means, such as by a threaded luer lock configured to engage an over-the-needle catheter having two threading tabs (commonly referred to as “rabbit ears”). In such embodiments, before the over-the-needle catheter  132  is inserted into the patient, the proximal end of the hollow needle  106  is positioned to pass through the valve housing  110  and between the first and second occluder proximal portions  150 ,  152  (which are in the closed position  124 ), where the proximal end of the hollow needle  106  is anchored in needle anchor assembly  108 . Specifically, the presence of the gap  142  between the seal guide pins  140 , as illustrated in  FIG. 4 , allows the hollow needle  106  to be passed through the entire length of the valve housing  110 , and through the catheter  132 . As will be understood by those of ordinary skill in the art, the hollow needle  106  will extend distally through the catheter  132 , and will protrude from the distal end of the catheter  132  to allow the introduction of the catheter  106  into a patient. 
         [0035]    Once the over-the-needle catheter  132  is inserted into the patient&#39;s vascular system, blood will begin to flow through the hollow needle  106 , and may fill a transparent flashback chamber (not shown) in the anchor assembly  108 , thereby indicating to the user that the catheter is properly placed. Then, the user can withdraw the hollow needle  106  from the over-the-needle catheter  132  by unscrewing the catheter assembly  108  and pulling on finger grips  134  while holding the valve housing  110  in place. As the hollow needle  106  is withdrawn from the over-the-needle catheter  132 , blood will begin to fill the over-the-needle catheter  132 . As described above, the presence of the gap  142  between the seal guide pins  140 , as illustrated in  FIG. 4 , allows the hollow needle  106  to be withdrawn through the valve housing  110  in a continuous, one-motion fashion. As the distal end of the hollow needle  106  is withdrawn through the hemostasis valve  100 , blood will fill the valve housing  110 , but will be prevented from flowing out of the valve housing  110  due to the occluder  120  being in the closed position  124 . Thus, the hollow needle  106  can be completely withdrawn from the hemostasis valve  100  without allowing any blood to leak from the patient or from the hemostasis valve  100  into the external environment. Additionally, this configuration eliminates the need for the user to “pinch off” the blood flow from the over-the-needle-catheter  132  during withdrawal of the hollow needle  106 , as is required when using conventional other-the-needle catheters. 
         [0036]      FIGS. 6 through 8  illustrate an alternative embodiment of a hemostasis valve  200  that does not include a seal guide pin, thus reducing manufacturing costs. As illustrated, the modified hemostasis valve  200  comprises a hollow valve housing  210 , an occluder  220 , a spring  270 , and a seal guide arm assembly  280 . The seal guide arm assembly  280  preferably comprises two seal guide arms  284  ending in pivot points  282 , although in other embodiments, the seal guide arm assembly  280  can comprise a different number of seal guide arms  284 . 
         [0037]    The seal guide assembly  280  serves the same function as the seal guide pins (described above), while being easier and less expensive to manufacture. In particular, the seal guide arm assembly  280  provides pivot points  282  over which the first and second occluder shafts  254 ,  256  slide as the occluder  220  moves within the valve housing. In such embodiments, the seal guide arms  284  are adjacent to an unoccupied region along a central axis of the hemostasis valve  200 , thereby allowing a hollow needle (not shown) to be passed through the hemostasis valve  200 . Preferably, the occluder  220  is modified to include slots  286  configured to accommodate the seal guide arms  284 . 
         [0038]    In any of the embodiments of the hemostasis valve described herein, after the hollow needle  106  and needle anchor assembly  108  have been removed from the catheter and valve housing  110 , other medical components  102  configured to remove blood from, or supply fluids to, the patient can be attached to the first port  112  of the valve housing  110 . As discussed above, placement of a medical component  102  on the first port  112  will cause the occluder  120  to move to the open position  122 , thereby providing access to the patient via the over-the-needle catheter  132 . In alternative embodiments, the valve housing  110  and the over-the-needle catheter  132  are formed into one component, such that the hemostasis valve  100  is integral with of the over-the-needle catheter  132 . 
         [0039]    The embodiments described herein ensure that the hemostasis valve  100  is closed whenever no medical component  102  is secured to the first port  112 . Whenever medical component  102  is removed from the first port  112 , either accidentally or intentionally, the restoring force of the spring  170  preferably causes the occluder  120  to return to the closed position  124 . This configuration prevents blood from disadvantageously leaving the body via the over-the-needle catheter  132 . 
         [0040]    Additionally, when medical component  102  is removed from the first port  112 , the proximal portions of first and second occluder proximal portions  150 ,  152  are exposed, thereby allowing the hemostasis valve  100  to be swabbed between uses. This configuration allows a single over-the-needle catheter  132  to be used for a plurality of different treatments once the over-the-needle catheter  132  has been inserted into the patient. Furthermore, by using this configuration, fluids are easily infused to, and fluids are easily withdrawn from, the patient&#39;s vascular system. 
         [0041]    One of ordinary skill in the art will recognize that the hemostasis valve described herein is not limited to use in conjunction with a patient&#39;s vascular system. In particular, the various embodiments of the hemostasis valve described herein can be used at a wound or surgical site by placing the over-the-needle catheter  132  into the patient&#39;s body at such a site. 
       SCOPE OF THE INVENTION 
       [0042]    The above presents a description of a preferred embodiment for the present hemostasis valve for use with an over-the-needle catheter, and of the manner and process of making and using it, in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains to make and use this hemostasis valve for use with an over-the-needle catheter. This hemostasis valve for use with an over-the-needle catheter is, however, susceptible to modifications and alternate constructions from that discussed above which are fully equivalent. Consequently, it is not the intention to limit this hemostasis valve for use with an over-the-needle catheter to the particular embodiments disclosed. On the contrary, the intention is to cover all modifications and alternate constructions coming within the spirit and scope of the hemostasis valve for use with an over-the-needle catheter as generally expressed by the following claims, which particularly point out and distinctly claim the subject matter of the hemostasis valve for use with an over-the-needle catheter.