Abstract:
A needle assembly having a hollow needle with a pointed distal end and a proximal end is disclosed. The assembly also includes a needle hub having a distal hub end fixedly connected to the needle, a proximal hub end having an opening, and a passageway extending therethrough between the distal end and the proximal end. A valve is disposed within the passageway, wherein the valve comprises a sealing member having at least one through-opening disposed therein and a plunger disposed proximate the sealing member and slidable between a first position wherein the at least one through-opening is closed such that the hollow needle and the proximal hub end are not in fluid communication with each other and a second position wherein the plunger biases the at least one through-opening to an open position, such that the hollow needle and the proximal hub end are in fluid communication with each other. A method of using the needle assembly is also disclosed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     The present application claims priority from U.S. Provisional Patent Application Ser. No. 60/495,988, filed on 18 Aug. 2003. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to a catheter insertion needle having a valve incorporated into the needle hub.  
       BACKGROUND OF THE INVENTION  
       [0003]     Catheters for the introduction or removal of fluids may be located in various venous locations and cavities throughout the body for introducing or removing fluids. Such catheterization may be performed by using a single catheter having multiple lumens. A typical example of a multiple lumen catheter is a dual lumen catheter in which one lumen introduces fluids and one lumen removes fluids. Catheterization may also be performed by using separate, single lumen catheters inserted through two different incisions into an area to be catheterized. Such multiple catheter assemblies are known as Tesio® catheters.  
         [0004]     Generally, to insert any catheter in a blood vessel, the vessel is identified by aspiration using an introducer device, such as a syringe having a long hollow needle in accordance with the Seldinger technique. Typically, a needle is attached to a syringe and inserted under the patient&#39;s skin, with the plunger being withdrawn as the needle is inserted. When blood enters the syringe attached to the needle, indicating that the vessel has been found, the syringe body is removed and a thin guide wire is introduced through the needle lumen and into the interior of the vessel. The needle is then removed, leaving a portion of the guide wire within the vessel and the remainder projecting outwardly to a point beyond the surface of the patient&#39;s skin. Other guide wire introducing devices and syringes are also available. At this point, the catheter is inserted by the physician over the guide wire using one of several known techniques.  
         [0005]     In the case of single-lumen catheters typically used in multiple catheter assemblies (e.g., a Tesio® catheter), a physician may use an introducer sheath. If a Tesio® catheter is used for hemodialysis, for example, each catheter may be inserted in two separate veins. Alternatively, each catheter may be inserted in two different locations of the same vein, such as the internal jugular vein or in a single insertion site as described in U.S. Pat. No. 5,624,413. The introducer sheath is simply a large, stiff, thin-walled tube which serves as a temporary conduit for the permanent catheter which is being placed. The introducer sheath is positioned by placing a dilator device inside of the introducer and passing both the dilator and the introducer together into the vessel over the guide wire. The guide wire, which is partially within the vessel after insertion as described above, and the dilator are then removed, leaving the thin-walled introducer sheath in place. The catheter is then placed through the introducer sheath.  
         [0006]     In each case, the first step is aspirating the vessel or area to be catheterized prior to introducing the guide wire. This is often troublesome, especially when aspirating blood vessels, due to the flashback of blood. Arterial blood may spurt from the needle insertion point with considerable force and may contact a physician or other attendant assisting the physician, causing the risk of contamination with blood borne pathogens, such as HIV virus or hepatitis. A second problem, which is of greater concern to the patient, is exposing certain venous blood vessels or other body cavities to atmospheric pressure. Veins are often under negative pressure as blood is being drawn back to the thoracic cavity due to the process of inspiration during the breathing cycle, and a hole in a venous blood vessel could lead to air being drawn into the blood vessel, creating an air embolism.  
         [0007]     In other types of catheterization procedures, such as a pleural effusion where fluid which collects around the lungs is drained, it is important to have a closed system guide wire introduction device which prevents atmospheric air from entering the thoracic cavity. Breathing movement creates negative pressure in the thoracic cavity, which, in combination with the air in the lungs, keeps the lungs expanded. The introduction of air into the thoracic cavity could cause the lungs to partially collapse. It is therefore important during the insertion of a guide wire for catheterization that the risk of introducing air into the thoracic cavity or a vessel be minimized.  
         [0008]     One attempt to solve these problems is disclosed in U.S. Pat. No. 5,613,663, which discloses a valve device within a two-piece housing that requires the valve to be assembled within the device prior to assembly of the two pieces that comprise the housing. However, the valve disclosed in this patent requires arterial blood pressure to close the valve. It would be beneficial to provide a valve that is housed in a one-piece housing to facilitate manufacturing of the device, and that includes a valve closure mechanism that does not require arterial blood pressure to close the valve.  
       BRIEF SUMMARY OF THE INVENTION  
       [0009]     Briefly, the present invention provides a needle assembly comprising a hollow needle having a pointed distal end and a proximal end. The assembly also includes a needle hub having a distal hub end fixedly connected to the needle, a proximal hub end having an opening, and a passageway extending therethrough between the distal end and the proximal end. A valve is disposed within the passageway, wherein the valve comprises a sealing member having at least one through-opening disposed therein and a plunger disposed proximate the sealing member and slidable between a first position wherein the at least one through-opening is closed such that the hollow needle and the proximal hub end are not in fluid communication with each other and a second position wherein the plunger biases the at least one through-opening to an open position, such that the hollow needle and the proximal hub end are in fluid communication with each other.  
         [0010]     The present invention also provides a method of inserting a guide wire into a blood vessel. The method comprises: providing the needle assembly comprising a hollow needle having a pointed distal end and a proximal end. The assembly also includes a needle hub having a distal hub end fixedly connected to the needle, a proximal hub end having an opening, and a passageway extending therethrough between the distal end and the proximal end. A valve is disposed within the passageway, wherein the valve comprises a sealing member having at least one through-opening disposed therein and a plunger disposed proximate the sealing member and slidable between a first position wherein the at least one through-opening is closed such that the hollow needle and the proximal hub end are not in fluid communication with each other and a second position wherein the plunger biases the at least one through-opening to an open position, such that the hollow needle and the proximal hub end are in fluid communication with each other. The method also includes: providing a body having a luer connector extending therefrom; providing a guide wire having a distal end; releasably connecting the body to the proximal end of the hub, wherein the luer connector disposes the plunger in a distal direction, wherein the plunger biases the at least one through-opening from a closed position to an open position; inserting the pointed distal end of the needle into the blood vessel; confirming proper placement of the needle in the blood vessel by drawing blood into the body; removing the body from the needle assembly, wherein the luer connector is disposed away from the plunger, wherein the sealing member biases the plunger in a proximal direction, and wherein the at least one through-opening returns to the closed position; inserting the distal end of the guide wire into the passageway, through the at least one through-opening, through the hollow needle and into the blood vessel; and removing the needle assembly from the blood vessel by sliding the needle assembly proximally along the guide wire.  
         [0011]     The present invention also provides a needle assembly comprising a hollow needle having a pointed distal end, a proximal end, and a longitudinal axis extending between the distal end and the proximal end. A needle hub having a distal hub end is fixedly connected to the needle. The needle hub includes a proximal hub end having an opening and a passageway extending therethrough along the longitudinal axis between the distal hub end and the proximal hub end. A valve is disposed within the passageway. The valve comprises a sealing member having at least one through-opening disposed along the longitudinal axis and a plunger disposed proximate the sealing member and slidable between a first position wherein the at least one through-opening is closed such that the hollow needle and the proximal hub end are not in fluid communication with each other and a second position wherein the plunger biases the at least one through-opening to an open position, such that the hollow needle and the proximal hub end are in fluid communication with each other. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate the presently preferred embodiments of the invention, and, together with the general description given above and the detailed description given below, serve to explain the features of the invention. In the drawings:  
         [0013]      FIG. 1  is a side profile view of a needle assembly according to the present invention.  
         [0014]      FIG. 2  is an enlarged perspective view, in section, of the needle hub shown in  FIG. 1 , with a hub valve in a closed position.  
         [0015]      FIG. 2A  is a greatly enlarged partial side profile view of  FIG. 2 , in section, showing retaining portions of the valve.  
         [0016]      FIG. 3  is a perspective view, in section, of the needle hub of  FIG. 2 , with a syringe opening the hub valve.  
         [0017]      FIG. 4  is a perspective view, in section, of the needle hub of  FIG. 2 , with a guide wire inserted through the hub valve.  
         [0018]      FIG. 5  is a perspective view, in section, of the needle hub of  FIG. 2 , with a bulb opening the hub valve.  
         [0019]      FIG. 6  is a perspective view, in section, of an alternate embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]     In the drawings, like numerals indicate like elements throughout. The terms “distal” and “proximal” refer to the insertion end and the connecting end, respectively, of the needle assembly according to the present invention. The terminology includes the words above specifically mentioned, derivatives thereof and words of similar import. The embodiments illustrated below are not intended to be exhaustive or to limit the invention to the precise form disclosed. These embodiments are chosen and described to best explain the principle of the invention and its application and practical use and to enable others skilled in the art to best utilize the invention.  
         [0021]     Referring now to  FIG. 1 , a catheter insertion needle assembly  100  according to the present invention is shown. The needle assembly  100  includes a needle  110  having a beveled distal tip  112  and a proximal end  114 . The needle  110  includes a hollow cannulating portion  116  that extends between the distal tip  112  and the proximal end  114 . Preferably, the needle  110  is constructed from stainless steel or some other suitable material.  
         [0022]     A generally hollow needle hub  120  is fixedly connected to the proximal end  114  of the needle  110 . Preferably, the hub  120  is of one-piece construction for ease of manufacture and cost issues. The hub  120  includes a distal end  122  that is fixedly connected to and encompasses the proximal end  114  of the needle  110 . The hub  120  also includes an open proximal end  124  and a passageway  126  extending between the proximal end  124  and the distal end  122 , and in fluid communication with the cannulating portion  116  of the needle  110 . A longitudinal axis  127  extends between the distal end  122  and the proximal end  124  along the passageway  126  and through the needle  110  between the distal tip  112  and the proximal end  114 .  
         [0023]     A distal end  128  of the passageway  126  is conically tapered from a larger diameter D 1  to a smaller diameter D 2  that is generally the same size as the diameter of the cannulating portion  116  of the needle  110 . A proximal end  130  of the passageway  126  has a diameter D 3  that is sized and tapered to accept a standard luer lock fitting, as is well known by those skilled in the art. The proximal end  124  also includes male threads  132  to facilitate connection of the needle assembly  100  to an external device, such as a syringe.  
         [0024]     Referring to the enlarged sectional view of the hub  120  shown in  FIG. 2 , a retaining ring  133  is disposed within the passageway  126  between the distal end  128  and the proximal end  130 . Referring to  FIG. 2A , the retaining ring  133  includes a tapered proximal face  133   a  and a straight distal face  133   b  that extends generally perpendicular to the length of the passageway  126 . Preferably, the hub  120  is constructed from Cyrolite® Med 2 Acrylic-Based, produced by Cyro Industries, Orange, Conn., although those skilled in the art will recognize that other suitable materials may be used.  
         [0025]     Referring back to  FIG. 2 , a valve  140  is disposed within the passageway  126 . The valve  140  includes a seal  142 , a support member  144 , and a plunger  146 . The seal  142  is disposed proximate to the distal end  128  of the passageway  126  and is generally annularly shaped, with a generally tubular side wall  147  and a closeable distal portion  148  that seals the passageway  126  to prevent fluid flow therethrough. The distal portion  148  includes a plurality of through-openings  150  that extend generally radially from the center of the distal portion  148 , preferably generally evenly radially spaced, toward the sidewall  147 . The seal  142  is generally disposed about the longitudinal axis  127 , with the longitudinal axis  127  extending through the intersection of the through-openings  150  in the distal portion  148  of the seal  142 . Preferably, three through-openings  150  are present (only one through-opening  150  is shown in  FIG. 2 ), although those skilled in the art will recognize that more or less than three through-openings  150  may be used. Preferably, the seal  142  is constructed from silicon or some other suitable material so that, when the valve  140  is opened, as will be described in more detail later herein, the through-openings  150  allow the distal portion  148  to open, allowing fluid flow through the seal  142 .  
         [0026]     The support member  144  is disposed within the passageway  126  just proximal of the seal  142 . The support member  144  has a generally annularly shaped cross section and includes a recessed distal portion  154  sized to allow the sidewall  147  of the seal  142  to snugly surround the recessed distal portion  154  and to bias the seal  142  to a most distal position within the passageway  126 . The retaining ring  133  allows the support member  144  to be inserted distally into the passageway  126 , but restrains the support member  144  from being removed proximally from the passageway  126 . Referring now to  FIG. 2A , the support member  144  further includes a retaining ring  156  disposed at a proximal end  158  of the support member  144 . The retaining ring  156  includes a tapered proximal face  156   a  and a straight distal face  156   b  that extends generally perpendicular to the length of the passageway  126 . Preferably, the support member  144  is constructed from pellethane, Cyrolite®, or some other suitable material.  
         [0027]     The plunger  146  includes a distal portion  160  that is disposed within the support member  144  and a proximal portion  162  that is disposed within the passageway  126  proximal of the support member  144 . The plunger  146  has a generally annularly shaped cross section. A most distal end  164  of the plunger  146  is generally conically tapered, preferably at an angle approximately equal to the conical taper of the distal end  128  of the passageway  126 . A most proximal end  166  of the plunger  146  includes a flange  168  that extends approximately to the sidewall of the passageway  126 . A plunger passageway  162  extends between the most distal end  164  and the most proximal end  166  of the plunger  146 .  
         [0028]     The proximal portion  162  of the plunger  146  has a smaller outer diameter than the distal portion  160  of the plunger  146 , with a step defining the interface between the proximal portion  162  and the distal portion  160 . When the plunger  146  is fully inserted into the support member  144 , the retaining ring  156  retains the plunger  146  within the support member  144  so that the distal portion  160  of the plunger  146  may not move proximally beyond the retaining ring  156 . Thus, distal portion of the plunger  146  is slidable distally between the retaining ring  156  and the distal end  128  of the passageway  126 . Preferably, the plunger  146  is constructed from isoplast, or some other suitable material.  
         [0029]     In operation, as shown in  FIG. 3 , a syringe  170  is releasably connected to the proximal end  124  of the hub  120 . Preferably, the syringe  170  includes a male luer connector  171  that is sized to sealably fit into the passageway  126  from the proximal end  130  of the passageway  126 . Also preferably, the syringe  170  includes female threads  172  that enable the syringe  170  to threadably engage the male threads  132  at the proximal end  124  of the hub  120 . The luer connector  171  engages the flange  168  and disposes the flange  168 , along with the plunger  146 , in a distal direction along the passageway  126 . The distal most distal end  164  of the plunger  146  engages the distal portion  148  of the seal  144 , opening valve  140  through the seal  142  along the through-openings  150 . The passageway  126  at the proximal end  124  of the hub  120  is now in fluid communication with the hollow cannulating portion  116  of the needle  110 .  
         [0030]     With the syringe  170  connected to the needle assembly  100 , forming a syringe assembly  180 , the syringe assembly  180  is inserted into a patient according to known methods. When the inserting physician believes that the syringe assembly  180  is properly inserted into a desired blood vessel, the physician draws back on the syringe plunger  173 , drawing a suction on the passageway  126  and the hollow cannulating portion  116  of the needle  110 . The suction draws blood from the vessel through the cannulating portion  116  of the needle  110 , through the now open valve  140  and the passageway  126  and into the syringe chamber  174 . When the physician confirms proper placement of the needle assembly  100  by the blood flashback in the syringe chamber  174 , the physician may then depress the plunger  173 , forcing the blood back through the needle assembly  100  and into the vessel so that the syringe  170  may be removed from the needle assembly  100 .  
         [0031]     As the syringe  170  is removed from the needle assembly  100  by unthreading the female threads  172  on the syringe  170  from the male threads  132  on the hub  120  and sliding the syringe  170  proximally relative to the needle assembly  100 , the luer connector  171  is disposed away from the flange  168 . The resiliency of the silicon or other material comprising the seal  142  allows the distal portion  148  of the seal  142  to bias the plunger  146  proximally, allowing the distal portion  148  of the seal  142  to close, shutting off fluid communication between the passageway  126  and the cannulating portion  116  of the needle  110 .  
         [0032]     The syringe  170  is now removed, and blood flow from the blood vessel through the needle assembly  110  is prevented by the seal  142  that is now closed. As shown in  FIG. 4 , a guide wire  190  is inserted into the proximal end  124  of the hub  120  according to known techniques. The distal end  192  of the guide wire  190  is able to be forced through the through-openings  150  in the distal portion  148  of the seal  142  so that the guide wire  190  may be partially inserted into the blood vessel through the cannulating portion  116  of the needle  110 . The resilience of the seal  142  seals the seal  142  around the guide wire  190  so that blood is restricted from flowing proximally through the seal  142 .  
         [0033]     Once the guide wire  190  is in a desired location within the blood vessel, the needle assembly  100  may be removed from the patient by sliding the needle assembly  100  proximally along the guide wire  190 . With the guide wire  190  in place, a catheter or other device (not shown) may be inserted into the blood vessel along the guide wire  190 .  
         [0034]     Those skilled in the art will recognize that a device other than the syringe  170  may be connected to the needle assembly  100 . For example, as shown in  FIG. 5 , a bulb  193  may be used. The bulb  193  is preferably of unitary construction and is constructed from a transparent or at least a translucent material, such as nylon or Lexan. The bulb  193  includes a male luer fitting  194  that is configured to fit into the passageway  126  in the same manner as the luer fitting  171  on the syringe  170 , as described above, and to open the valve  140  as described above. The bulb  193  includes a swivel lock  195  having female threads  196  that allow the bulb  193  to be threadingly connected to the needle assembly  100  via the male threads  132  at the proximal end  124  of the hub  120 . A bulb portion  197  allows any blood that flashes into the bulb  193  through the needle assembly  110  to be easily seen due to the magnification properties of the bulbous shape of the bulb portion  197 . The bulb  193  also includes a proximal end  198  that includes a female luer fitting  198 a and a male thread  198   b  for connection of an exterior device, such as the syringe  170 , to the bulb  193 .  
         [0035]     In operation, the bulb  193  is releasably connected to the needle hub  120  by inserting the male luer fitting  194  into the passageway  126  and engaging the thread  196  on the swivel lock  195  with the thread  132  on the hub  120 . The male luer fitting  194  engages the plunger  146 , forcing the plunger  146  distally toward the distal end  122  of the hub  120 . The plunger  146  engages the seal  142 , opening the valve  140  through the seal  142  along the through-openings  150 .  
         [0036]     Although not shown, the syringe  170  may be connected to the proximal end  198  of the bulb  193  by inserting the male luer fitting  171  into the female luer fitting  198   a  and engaging the female thread  172  with the male thread  198   b.  The cannulating portion  116  of the needle  110  is now in fluid communication with the syringe chamber  174 .  
         [0037]     The needle assembly  100  is next inserted into the patient according to known techniques. The plunger  174  is drawn proximally, drawing blood from the patient, through the cannulating portion  116  of the needle  110 , through the valve  140 , and into the bulb  173 , where the inserting physician can see the blood flash into the bulb portion  197  to confirm that the needle  110  is inserted properly.  
         [0038]     The bulb  193  is then disconnected from the needle assembly  100  and the valve  140  closes as described above. The guide wire  170  may now be inserted, as is also described above.  
         [0039]     Those skilled in the art will recognize that the valve  140  may be used in other devices than the needle assembly  100  as described above. For example, the valve  140  may be inserted into a luer  200 , as shown in  FIG. 6 . The luer  200  may be connected to a proximal end of a catheter lumen  202  and includes a proximal luer end  204 , a distal luer end  206 , and a longitudinal passage  208  extending between the proximal luer end  204  and the distal luer end  206 . A luer wall  209  forms the luer passage  208 . The luer  200  also includes a longitudinal axis  210  extending through the passage  208  between the proximal luer end  204  and the distal luer end  206 .  
         [0040]     The valve  140  is disposed within the longitudinal passage  208  such that the seal  142  is disposed distal of the plunger  146 . The support member  144  is disposed between the plunger  146  and the luer wall  209 . Operation of the valve  140  within the luer  200  is the same as the operation of the valve  140  within the needle hub  120  as described above.  
         [0041]     Further, the present invention is not limited to a syringe or a luer. Those skilled in the art will recognize that the valve  140  may be incorporated into any luer lock-type pathway that requires unobstructed flow when a male luer is inserted into the pathway and positive closure when the male luer is removed from the pathway.  
         [0042]     It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.