Abstract:
A syringe includes a body and a plunger disposed therein. The body includes a nozzle formed therein and at least one hub member connected thereto or integrally formed thereon for holding an end of a connector tube. The connector tube includes two ends, each end preferably being connected to a respective hub member to retain the connector tube in contact with the syringe. Preferably, the syringe and the connector tube are packaged in a pre-connected condition for ease of use by the customer. Furthermore, flexible inlet tubing for connection to a syringe for filling the syringe with contrast media, for example, is described. The inlet tubing permits filling of the syringe from either a bag or a bottle and may remain attached to the syringe so that it forms at least a part of the connection to the patient. In addition, an apparatus for facilitating the purge of air from a connector tube that will ultimately be connected between a syringe and a patient is described. The apparatus includes a purging tube connected to the distal end of the connector tubing from the syringe. The purging tube includes a venting cap at its distal end. A flow inhibitor is positioned under the venting cap to cooperate with the venting cap by discouraging the discharge of fluid from the distal end of the purging tube while permitting the discharge of air therefrom.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Provisional Application Serial No. 60/169,413, filed on Dec. 7, 1999, Provisional Application Serial No. 60/229,548, filed on Sep. 5, 2000, and Provisional Application No. 60/229,549, filed on Sep. 5, 2000, the contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to syringes for use with injectors and, more particularly, to syringes, syringe tubing and fluid transfer systems having features that improve the ease of use and efficiency of loading fluid in and ejecting fluid from the syringes. 
     A number of injector-actuated syringes and powered injectors for use in medical procedures such as angiography, computed tomography, ultrasound and MRI have been developed. For example, U.S. Pat. No. 4,006,736 discloses an apparatus for injecting fluid into the vascular system of a human being or an animal. Likewise, U.S. Pat. No. 4,677,980 discloses an angiographic injector and syringe wherein the drive member of the injector can be connected to, or disconnected from, the syringe plunger at any point along the travel path of the plunger via a releasable mechanism requiring rotation of the syringe plunger relative to the piston. 
     A front-loading syringe and injector system is disclosed in U.S. Pat. No. 5,383,858, the disclosure of which is hereby incorporated by reference. The syringes disclosed in U.S. Patent No. 5,383,858 can be securely front-loaded directly and accurately on the injector or on a pressure jacket attached to the injector, thereby facilitating the loading-unloading operation as compared to prior systems. 
     To load syringes with contrast fluid, a user typically connects a fill tube to the front nozzle or discharge outlet of the syringe and places the other end of the tube in a bottle or bag of contrast medium or other fluid. The plunger of the syringe is retracted (usually by means of the injector piston) to aspirate the contrast into the syringe until the desired amount is loaded into the syringe. After the syringe is filled, the fill tube is then typically discarded. Often, contrast or other fluid contained in the fill tube may drip therefrom onto the floor or the injector. 
     After the syringe is filled with fluid, a connector tube is connected to the discharge outlet of the syringe and the connecting tube is primed (typically by advancing the plunger in the syringe) to eject air from the syringe and the connector tube (i.e., to prevent air from being injected into the patient). While this technique is entirely effective in purging air from the tubing connected to the syringe, it is undesirable to have liquids dispensed from the end of the tube. Often, the liquids dispensed from the end of the tube foul the exterior surface of the tubing or fall onto the floor. When dealing with contrast media, this is particularly undesirable because the media is very sticky and has a tendency to migrate to whatever surface the operator touches after purging the tube. 
     When the patient is ready for the injection, the patient end of the connector tube is connected to, for example, a catheter, in a patient. During the time period between priming the connector tube and connecting the patient end of the connector tube to the patient, the patient end of the connector tube should be maintained in a sterile condition. 
     A significant amount of time and attention is required to properly load syringes with fluid and to connect and prime the connector tube. Consequently, it is very desirable to develop a new syringe or to improve existing syringes to reduce operator time and involvement in loading the syringe with fluid and/or in priming and connecting the connector tubing, while also minimizing or eliminating discharge of contrast medium or other fluid from the syringe or tubing associated with the syringe. 
     SUMMARY OF THE INVENTION 
     The present invention provides syringes, syringe tubing and a fluid transfer system that reduces the amount of time and vigilance necessary to load the syringe with fluid, such as contrast fluid, to connect the syringe to a patient and to prime the syringe and connector tube assembly. In addition, the present invention provides a purge tube that is designed to minimize leakage of contrast medium or other fluid therefrom. Further, the present invention provides a syringe and connector tube assembly operable to maintain the sterility of the connector tube for subsequent connection to a patient. 
     In a first aspect, a syringe includes a body and a plunger disposed therein. The body includes a nozzle formed therein and a latch connected thereto or integrally formed thereon for holding a second end of a fill tube. The first end of the fill tube is preferably pre-connected to the nozzle. A plastic or other sheath is removably disposed around the fill tube between the first and second ends to maintain the fill tube in a clean and/or sterile condition prior to use for filling/loading the syringe with contrast. 
     In addition, the diameter of the syringe nozzle may be enlarged to provide for increased volumetric fluid flow (and thereby faster fluid filling/loading) into the syringe. Preferably, the internal diameter of the syringe may be increased from 0.1 inches to approximately 0.2 to 0.25 inches. The enlarged syringe nozzle may also decrease the formation of air bubbles, which typically occurs during syringe filling, thereby resulting in less air needing to be expelled from the syringe and the connector tubing prior to injection and decreased risk of an inadvertent air injection into a patient. 
     In a preferred embodiment, the syringe is packaged with the first end of the fill tube pre-connected to the nozzle and the second end held in the latch. The sheath preferably covers the fill tube. After the syringe is removed from its packaging, the second end of the fill tube is removed from the latch and the sheath is removed from the fill tube and discarded. The second end of the fill tube is then placed in a contrast or other fluid container. The plunger of the syringe is retracted to fill the syringe with the fluid in the container. After a sufficient amount of the fluid is aspirated into the syringe, the fill tube may then be disconnected from the syringe and, preferably, discarded. 
     In a second aspect, a syringe includes a body and a plunger disposed therein. The body includes a nozzle formed therein and at least one hub member connected thereto or integrally formed thereon for holding an end of a connector tube. In a preferred embodiment, the at least one hub member comprises two hub members disposed on the syringe body. The connector tube includes two ends, each end being connected to a respective hub member to retain the connector tube in contact with the syringe. Preferably, the syringe and the connector tube are packaged in a pre-connected condition for ease of use by the customer. 
     After the syringe is filled with fluid and the fill tube is disconnected from the discharge outlet or nozzle of the syringe, one end of the connector tube is removed from a hub member and connected to the nozzle of the syringe. The second end of the connector tube is removed from the other hub member and held, preferably over a refuse or other container (i.e., to collect any fluid ejected from the connector tube during the priming operation), while the syringe and connector tube is primed to remove air therefrom. After the priming operation is completed, the second end of the connector tube is replaced on the hub member on the syringe to maintain it in a sterile condition and/or an “out of the way” location until the second or patient end of the connector tube is connected to the patient. 
     Further, the connector tube may include one or more tethered caps to prevent the caps from being dropped on the floor or misplaced. The caps are used to close the open ends of the connector tube to, for example, prevent dust or other contaminants from entering the connector tube. After the syringe is filled and/or primed, a cap may be placed on the open, patient end of the connector tube to maintain sterility. In a preferred embodiment, the caps are tethered to the connector tube by a plastic or other member connected between each of the caps and the connector tube. 
     In a third aspect, a fluid transfer system includes a syringe, a fluid container and a transfer device for transferring fluid, such as contrast, from the container to the syringe to fill same. In a preferred embodiment, the transfer device includes a spike for puncturing the seal of the fluid container, a container holder for holding the fluid container on the spike, a valve for allowing fluid to enter the syringe and a syringe support member for aligning the syringe nozzle with the valve. 
     After the syringe is mounted on an injector, the spike of the transfer device is used to pierce the seal of the fluid container. The syringe support member of the transfer device is then placed over the nozzle of the syringe. The luer tip of the syringe nozzle engages the valve of the transfer device, thereby allowing the contents of the fluid container to flow into the syringe. To aspirate the contents of the fluid container into the syringe, the piston of the injector retracts the plunger of the syringe. 
     The container holder functions to maintain the fluid container in contact with the spike and the fluid transfer device as the fluid is transferred from the fluid container to the syringe. In addition, the syringe support member maintains the nozzle of the syringe aligned and engaged with the valve, which is preferably a check valve. In a preferred embodiment, the transfer system is disposable. 
     In a fourth aspect, a syringe includes a body and a plunger disposed therein. The body includes a nozzle formed therein. Flexible inlet tubing may be pre-connected or permanently connected to the nozzle of the syringe (or provided separately) to facilitate filling of the syringe prior to a medical procedure. The flexible tubing may remain attached to the nozzle of the syringe after filling thereof to reduce waste and the opportunity for contrast or other fluid from dripping from the syringe nozzle or the inlet tubing. 
     In a fifth aspect, the present invention provides a purge tube that can be connected to the end of a connector tube that delivers contrast media or other fluid to a patient. The purge tube may minimize or eliminate the discharge of contrast media from the end of the connector tube that delivers the media to the patient when the syringe and connector tube assembly is purged. In a preferred embodiment, the purge tube may collect any discharged liquid from the end of the connector tube that delivers the contrast media to the patient. The purge tube may then be removed from the connector tube and discarded to minimize or eliminate contamination of other surfaces by the liquid captured thereby. 
     Other aspects of the invention and their attendant advantages will be discerned from the following detailed description when read in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various embodiments of the present invention will be described below, which reference to the following drawings, in which: 
     FIG. 1 is a perspective view of an embodiment of the syringe of the present invention in a first orientation; 
     FIG. 2 is a partially exploded, perspective view of the syringe of FIG. 1 in a second orientation; 
     FIG. 3 is a perspective view of a connector tube with tethered caps for the ends thereof; 
     FIG. 4 is an exploded, perspective view of a preferred embodiment of the fluid transfer system of the present invention; 
     FIG. 5 is an isometric illustration of a syringe and flexible inlet tubing of the present invention; 
     FIG. 6 is an isometric illustration of an alternate embodiment of the flexible tubing illustrated in FIG. 5; 
     FIG. 7 is an isometric view of a purging tube of the present invention shown connected to a syringe; 
     FIG. 8 is an enlarged view of the purging tube shown in FIG. 7; 
     FIG. 9 is an isometric, exploded view of the purging tube shown in FIGS. 7 and 8; and 
     FIG. 10 is an isometric view of a syringe and the purging tube of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As best shown in FIG. 1, a syringe  10  includes a body portion  12  and a plunger (not shown) movably disposed therein. The body portion  12  defines a nozzle or discharge outlet  16  at the front end thereof for discharging fluid contained within the syringe  10  to a patient and a latch or retention member  24  preferably disposed on a rearward end thereof. 
     The body portion  12  further includes at least two mounting flanges  17  and a sealing flange  19  for securely mounting the syringe on the front of an injector (not shown), as disclosed in U.S. Pat. No. 5,383,858, the contents of which are hereby incorporated by reference. 
     A fill tube  18  includes a first end  20  removably connected to the nozzle  16  of the syringe  10  and a second end  22  removably connected to the latch  24  on the body  12  of the syringe. A sheath  26 , which may be formed of plastic or other suitable material, covers the fill tube  18  to maintain the fill tube in a clean or sterile condition. 
     The syringe  10  is preferably packaged in a container (not shown) with the first end  20  of the fill tube  18  pre-connected to the luer tip (not shown) of the nozzle  16  and the second end  22  pre-connected to the latch  24 . In that manner, the operator does not have to connect the fill tube  18  to the syringe  10  before filling the syringe with fluid, which is convenient and saves operator time. 
     In use, after the syringe  10  is removed from its container, the second end  22  of the fill tube  18  is disconnected from the latch  24  and the sheath  26  is removed from the fill tube  18  (via the free second end  22 ). The second end  22  of the fill tube  18  may then be placed in a fluid container (not shown), such as a contrast container, to fill/load the syringe  10  with fluid. The fluid is aspirated into the syringe  10  by retracting the plunger within the syringe  10 , preferably by means of the injector piston (not shown). After the syringe  10  is filled, the first end  20  of the fill tube  18  can be removed from the nozzle  16  of the syringe  10 , and the fill tube  18  discarded. 
     In addition, as best shown in FIGS. 2 and 3, a connector tube  28  may be pre-connected to the syringe  10 . The connector tube  28  includes a first end  30  for connection to the nozzle  16  of the syringe  10  and a second or patient end  32  for connection to a patient (not shown). The syringe preferably includes two hub members  34  connected to or formed on the body portion  12  of the syringe. The ends  30 ,  32  of the connector tube  28  are removably connected to a respective hub member  34  on the syringe  10 . 
     In use, the syringe  10  is preferably packaged with the ends  30 ,  32  of the connector tube  28  connected to the hub members  34  on the syringe  10 . After the syringe is filled with fluid, the first end  30  of the connector tube  28  is connected to the nozzle  16  of the syringe  10 . The syringe  10  and the connector tube  28  are then primed to remove air therefrom by advancing the plunger within the syringe  10 . As a result, the air contained within the syringe  10 , along with possibly a small amount of fluid,  10  is ejected from the syringe  10  and the second end  32  of the connector tube  28 . 
     After the connector tube  28  is primed, the second end  32  of the tube  28  is reconnected to a hub member  34  until the operator is ready to connect the second end  32  to the patient. Alternately, the second end  32  may be connected to or draped over the latch  24  on the syringe  10 . By mounting the second end  32  of the connector tube  28  on the hub member  34  or the latch  24 , the second end  22  is kept clean and/or sterile and is placed in an “out of the way” location. Further, by effectively closing the open, second end  32  of the connector tube  28  with a hub member  34 , fluid is prevented from leaking from the connector tube  28  onto the floor or elsewhere. 
     Moreover, after the injection procedure is completed, the second end  32  of the connector tube  28  may be removed from the patient and reconnected to a hub member  34  to prevent fluid spillage. After the syringe  10  is removed from the injector, the syringe  10  and connector tube  28  can be disposed of as a unit. 
     As shown in FIG. 3, the connector tube  28  may also include tethered caps  36  for each end  30 ,  32  thereof. The caps  36  may be used to close the open ends  30 ,  32  of the connector tube  28  to prevent dust and other contaminants from contaminating the connector tube  28  and to prevent fluid from leaking therefrom. For example, after the connector tube  28  has been attached to the syringe  10  and primed to remove air therefrom, a cap  36  may be placed over the open, patient end  32  of the connector tube  287  to maintain sterility prior to injection. 
     In a preferred embodiment, the caps  36  are tethered to the connector tube  28  by means of tethers  38  disposed between the connector tube  28  and the caps  36 . The tethers  38  may be formed of plastic or any other suitable material. 
     As shown in FIG. 4, a fluid transfer system  40  includes a syringe  42 , a fluid container  44  and a transfer device  46  for transferring fluid, such as contrast, from the container  44  to the syringe  42  to fill it. (The syringe  42  may contain the same features as discussed above with respect to the syringe  10  shown in FIGS. 1 and 2.) 
     In a preferred embodiment, the transfer device  46  includes a conventional spike  48  for puncturing the seal of the fluid container  44 , a container holder or cup  50  for holding the fluid container  44  on the spike  48 , a valve (not shown), such as a check valve, for allowing fluid to enter the syringe  42  and a syringe support member or sleeve  54  for holding the syringe  42  in relationship to the transfer device  46 . 
     After the syringe  42  is mounted on an injector (not shown), the plunger (not shown) is advanced to expel air from the syringe  42 . The syringe  42  is then ready to be filled with fluid. The transfer device  46  may then be inserted onto the fluid container  44  such that the spike  48  pierces the seal of the fluid container  44 . The syringe support member  54  of the transfer device  46  may then be placed over the nozzle of the syringe  42 . Within the support member  54 , the luer tip  56  of the syringe  42  engages and actuates the valve to open a passage for fluid to flow from the container  44  to the syringe  42 . To aspirate the contents of the fluid container  44  into the syringe  42 , the injector piston (not shown) retracts the plunger (not shown) of the syringe  42 . 
     In a preferred embodiment, when the luer tip  56  of the syringe  42  opens the valve, fluid will not substantially flow from the container  44  until the plunger is retracted to create a suction to aspirate fluid into the syringe  42 . This design prevents fluid from inadvertently spilling from the container  44 . Further, the container holder  50  and the syringe support member  54  are designed to impart rigidity to the system and to maintain the syringe  42  and the container  44  in contact with the transfer device  46 . In a preferred embodiment, the transfer system  46  is disposable. 
     A syringe and an inlet tube of the present invention are shown in FIGS. 5 and 6. The syringe  100  includes a cylindrical body  112  and a frusto-conical forward end  114  that transitions into a discharge end  116 . A flexible inlet tube  118  is connected to the discharge end  116 . Preferably, the flexible tube  118  contains a flexible (or corrugated) section  120  disposed between two smooth (or non-corrugated) sections  122 ,  124 . Flexible tubing  118  may be composed of any suitable polymeric material so long as the material is flexible, durable, and suitable for medical use. 
     While flexible tubing  118  is illustrated with two smooth sections  122 ,  124  connected to one another by a corrugated section  120 , other alternative constructions are contemplated within the scope of the present invention. For example, the flexible tube may include one corrugated section and one smooth (non-corrugated) section. In still another embodiment, the flexible tube may not include any corrugated sections at all, but instead, may incorporate some other alternative flexible section or sections to accomplish the same objective. 
     Flexible tubing  118  may be releasably connected to discharge or dispensing end  116  of syringe  110  or it may be permanently attached thereto. Similarly, flexible tubing  118  may be supplied with syringe  110  or it may be supplied separately and used with syringe  110 . As can be readily appreciated, the flexible nature of inlet tube  118  allows it to be easily maneuvered for use with fluid bags or bottles to fill the syringe  110 . 
     At the end of flexible tubing  118  opposite to the end connected to dispensing end  116  of syringe  110 , a luer lock  126  is provided. After filling syringe  110 , once filler bag or bottle has been removed from flexible tubing  118 , a low-pressure connector tubing (“LPCT”) may be connected directly to luer lock  126  for connection to the patient. 
     FIG. 6 illustrates another embodiment of the present invention, which is specifically directed at the filling of syringe  110  from a bottle of contrast medium. A tube extension  128  is illustrated that releasably connects to luer lock  126 . The extension tubing  128  is inserted into the bottle of contrast media for filling syringe  110 . After syringe  110  is filled, extension tubing  128  is removed from the bottle, disconnected from luer lock  126 , and discarded. After purging, syringe  110  may then be connected to the patient. 
     The embodiment shown in FIG. 6 facilitates filling of syringe  110 . In addition, tubing extension  128 , which is usually covered with contrast media after syringe  110  is filled, may be discarded to reduce contamination of equipment with contrast media that may remain thereon. 
     A syringe and purging tube of the present invention is shown in FIGS. 7-10. FIG. 7 illustrates a syringe  210  with a discharge end  212 . Discharge end  212  is usually provided with a luer lock so that a tube  214 , such as a low-pressure connector tubing (or “LPCT”), may be connected thereto. 
     In the embodiment illustrated, connector tube  124  includes a luer lock  216  at a distal end. A purging tube  218  is removably connected to the luer lock  216  of the connector tube  214 . Purging tube  218 , which is shown in detail in FIG. 8, has a vented cap  220  at the distal end thereof. As illustrated in FIG. 9, between purging tube  218  and vented cap  220  are disposed two additional elements, a flow preventor  222  and a seal (or spacer)  224 . Seal  224  is disposed between purging tube  218  and flow preventor  222 . Flow preventor  222  may be any suitable material (including paper) that inhibits the flow of contrast media, but allows air to pass therethrough and out of the end of purging tube  218 . The vented cap  220 , in a preferred embodiment, provides a support structure for the flow preventor  222  and allows air to pass therethrough from the flow preventor  222  to the atmosphere. In the preferred embodiment, flow preventor  222  is made of Goretex®, which is the trade name of a vapor-breathable fabric made by W. L. Gore and Associates. 
     After a syringe  210  is filled with a fluid, such as a contrast media, the air remaining in the LPCT  214  and the syringe  210  should be purged (e.g., by advancing the syringe plunger) before the LPCT  214  is connected to a patient. During purging, some contrast media will often be forced out of the distal end of the LPCT  214 . Purging tube  218  is provided with a sufficiently large interior volume to collect that discharged media. In a preferred embodiment, the purging tube  218  is adapted to contain approximately 3 ml of fluid. In addition, the purge tube  218  is preferably pre-connected to the distal end of the LPCT  214 . The vented cap  220  allows air to be discharged from the purge tube  218  and the flow preventor  222  inhibits leakage of contrast media from the distal end of purging tube  218  during the purging operation. As can be appreciated, while flow preventor  22  does inhibit the flow of fluid therethrough, it will not prevent fluid flow if a sufficient volume of fluid is discharged into the purge tube  218 . Therefore, during the purging operation, an operator should be careful not to discharge into the purge tube  218  more fluid than the fluid volume capacity of the purge tube  218 . 
     During the purging operation, the distal end of the purge tube  218  is preferably held in an elevated position (i.e., opposite from the ground) to further prevent fluid from being discharged from the purge tube  218 . However, the purging operation could be conducted with the distal end of the purge tube  218  held in any orientation. After the purging operation is completed, the purge tube  218  contains the fluid discharged from the syringe  210  and the connector tubing  214 . To prevent the discharged fluid from leaking out of the proximal end of the purge tube  218  (i.e., the end connected to the distal end of the LPCT  214 ), the proximal end of the purge tube  218  is preferably elevated prior to or immediately after being disconnected from the connector tube  214 . Thereafter, the purge tube  218  is preferably discarded and the connector tube  214  is connected to a catheter in a patient for an injection procedure. 
     Purging tube  218  offers at least one further advantage. With purging tube  218 , it is possible to design an injector that has an automatic purge feature. See, for example, the auto prime feature described in PCT International Application No. PCT/US00/31991, filed on Nov. 21, 2000, the contents of which are hereby incorporated by reference. Specifically, the injector (not shown) may have a button that the practitioner may push to clear air from syringe  210  and the LPCT  214 . Upon actuation of the auto purge feature, the injector would advance the plunger in the syringe by a predetermined amount. By providing purging tube  218  with a sufficient interior volume, the auto purge feature should not exceed the interior volume of the purging tube  218 . 
     FIG. 10 illustrates the purging tube  218  of the present invention in use with a syringe  230  having a discharge end  232 . Syringe  230  may be of the type typically used for the injection of contrast media into a patient for vascular imaging, for example. While syringe  230  differs from syringe  210  shown in FIG. 7, in all other respects the use and function of purging tube  218  is the same as described above. 
     In an alternate embodiment, the vented cap  220  and the flow preventor  222  may be positioned at a location between the proximal and distal ends of the purge tube  218 . When fluid is discharged into the purge tube  218  past the vented cap  220  and the flow preventor  222  (i.e., to the distal side thereof) during the purging operation, the fluid will cooperate with the flow preventor  222  to prevent the fluid from leaking from the proximal and distal ends of the purge tube  218  after the purge tube  218  is disconnected from the connector tube  214 . This alternate design may reduce the need for the operator to elevate the proximal end of the purge tube  218  prior to or immediately after it is disconnected from the connector tube  218 , as discussed above with respect to the preferred embodiment. 
     In yet another embodiment, the vented cap  220  and flow preventor  222  may be replaced with a one-way check valve (not shown) that is biased in a closed position. During the purging operation, the check valve would be forced open to allow air to pass therethrough. After the purging operation is completed, the check valve will close and, when the purge tube  218  is disconnected from the LPCT  214 , operate to prevent fluid from leaking from the proximal and distal ends of the purge tube  218 . 
     Furthermore, while one aspect of the present invention has been described above in terms of a purging “tube,” it should be appreciated that the term “tube” is not limiting and should be construed to include all suitable types of structures and containers for retaining the discharged fluid from the syringe and the LPCT  214 . 
     Although the present invention has been described in detail in connection with the above examples and embodiments, it is to be understood that such detail is solely for that purpose and that those skilled in the art can make variations without departing from the invention. The invention is not limited to the disclosed embodiments, but may be practiced within the full scope of the appended claims.