Abstract:
Safety syringe with a syringe barrel and an exterior retraction trunk. The trunk is formed outside of the barrel, forming an exterior chamber fixed to the barrel. A needle cannula carriage is held within the distal end of the retraction trunk. A needle cannula module is fixed to the distal end of the needle cannula carriage, wherein a cannula provides fluid communication from the needle cannula module, through the needle cannula carriage, through the retraction trunk and into the syringe barrel. A plunger is provided in the inner surfaces of the syringe barrel and the outer surface of the retraction trunk. When desired, a button may be pushed causing the latching means to release the needle cannula carriage, allowing the biasing means to thrust said carriage with the needle cannula into the exterior retraction trunk, thereby preventing the needle cannula from accidentally pricking others or being reused.

Description:
[0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 09/654,668 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to safety syringes having retractable needle cannulas.  
           [0004]    2. Background of the Related Art  
           [0005]    There are safety syringe devices of various designs that will allow the needle to retract into either the barrel or plunger of the syringe. Some of these devices are described in U.S. Pat. No 4,973,316 (Dysarz), U.S. Pat. No. 4,978,343 (Dysarz), U.S. Pat. No. 5,180,369 (Dysarz), U.S. Pat. No. 5,267,961 (Shaw), U.S. Pat. No. 5,019,044 (Tsao), U.S. Pat. No. 5,084,018 (Tsao), U.S. Pat. No. 5,385,551 (Shaw), U.S. Pat. No. 5,389,076 (Shaw), U.S. Pat. No. 5,201,710 (Caselli), U.S. Pat. No. 6,010,486 (Carter et al), U.S. Pat. No. 5,120,310 (Shaw), U.S. Pat. No. 5,188,613 (Shaw), and U.S. Pat. No. 6,033,385 (Liu). Although these devices reduce accidental needle sticks, an operator of the devices may cause the needle to prematurely retract during the process of filling the syringe (aspiration) or while medication is being injected into a body.  
           [0006]    For example, during aspiration the plunger is pushed in as far as it will go into the syringe (just prior to pulling the plunger back to draw the medication or other fluid from a container or body) such that the plunger may trigger the retraction mechanism and cause the needle to prematurely retract, thereby resulting in the loss of the needle cannula, an expensive syringe, more expensive medication, and even more expensive labor (doctor, nurse, etc). Usually the operator of the device does not know at what precise point to stop pressing the plunger into the syringe prior to or during aspiration.  
           [0007]    Other types of safety syringes are devices with a sleeve or a sheath that will cover the needle after it has been used. To aspirate or fill this type of syringe, one must sight the medication through two layers of plastic or glass; if a clear fluid is being drawn into the syringe it may not be possible to see the necessary dosage.  
           [0008]    Additionally, most of the devices mentioned above are not modular, wherein a needle cannula of any size may be used with a syringe of any size. Rather, the needle cannula is made as part of the syringe, and the two are not interchangeable with other needle cannulas or syringes of different sizes or capacities. Safety syringes that are modular include the devices disclosed in U.S. Pat. No. 5,891,093 (Dysarz), U.S. Pat. No. 6,016,595 (Dysarz), U.S. Pat. No. 5,935,113 (Dysarz), and U.S. Pat. No. 6,010,486 (Carter et al).  
           [0009]    Therefore, there remains a need for a safety syringe with a positive latching device that will remain latched during aspiration and that can only be released with a positive release means when the user desires to release the needle-latching device. Furthermore, there remains a need for a safety syringe that is modular, wherein various needle cannulas are interchangeable with various syringes. It would be desirable if the modular safety syringe were compatible with existing inventories of needles.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention provides a retractable safety syringe module, comprising a syringe barrel forming a fluid chamber, and an exterior retraction trunk. The exterior retraction trunk forms a chamber fixed to the syringe barrel, wherein the retraction trunk has a port in fluid communication with the syringe barrel.  
           [0011]    The syringe barrel comprises a chamber and a plunger extending through a proximal end of the chamber, the plunger having a sliding gasket formed along its distal end for sealing against the interior walls of the chamber. A biased needle cannula carriage is releasably secured against the sealing collar, the biased needle cannula carriage having a connector for selectively receiving a needle cannula and a passage providing fluid communication between the sealing collar port and the connector. A retaining member releasably secures the biased needle cannula carriage against the sealing collar.  
           [0012]    The needle cannula carriage is biased in the proximal direction into the retraction trunk and has dimensions allowing it to retract into the retraction trunk without restriction. A needle cannula is selectively and/or disconnectably connectable to the carriage, preferably by a connector selected from screw threads, Luer-Loks® (Becton Dickinson, Franklin Lakes, N.J.), snap-on fittings or slip-on fittings. An exterior surface of the carriage mates with the interior surface of the sealing collar, wherein the mating surfaces are preferably selected from shoulders, steps and cones. A retaining member, such as a carriage stop arm, is provided to secure the carriage against the sealing collar.  
           [0013]    One aspect of the invention provides a kit of components for assembling safety syringes, the kit comprising two or more safety syringe modules, optionally having different diameters, and two or more needle cannula modules, optionally having different sizes. Each safety syringe module and each needle cannula module are provided in accordance with any embodiment described herein. The connectors in any of the two or more safety syringe modules are sealably securable to any of the connectors in the two or more needle cannula modules to provide fluid communication between the needle cannula and the passage in the carriage base. Specifically, the connectors are preferably selected from threads, Luer-Loks® (Becton Dickinson, Franklin Lakes, N.J.), snap-on fittings or slip-on fittings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    The features of the present invention can best be understood by reference to the following descriptions taken in conjunction with the accompanying drawings wherein like numerals indicate like parts.  
         [0015]    [0015]FIG. 1 is a section elevation of the syringe of the first preferred embodiment.  
         [0016]    [0016]FIG. 2 an enlarged section elevation view of the needle cannula carriage as taken from FIG. 1.  
         [0017]    [0017]FIG. 3 is a section plan view of the needle cannula carriage as taken through FIG. 1.  
         [0018]    [0018]FIG. 4 is a section plan view of the syringe, the needle cannula carriage and the retraction trunk as taken through FIG. 1.  
         [0019]    [0019]FIG. 5 is a section elevation of the needle cannula carriage, and the needle cannula released and thrust into the retraction trunk.  
         [0020]    [0020]FIG. 6 is a section elevation of the second preferred embodiment.  
         [0021]    [0021]FIG. 7 is a section plan view of the needle cannula module connection with at least two syringe trunks fixed to the retraction trunk as taken through FIG. 6.  
         [0022]    [0022]FIG. 8 is a section elevation of the device of the second preferred embodiment showing the needle carriage and needle cannula released.  
         [0023]    [0023]FIG. 9 is a section elevation as taken through FIG. 8. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]    Referring to FIG. 1, there is shown a section elevation of a syringe  1  of the first preferred embodiment. The syringe is formed into an syringe barrel  7  with an inside surface and an outside surface, a distal end and a proximal end wherein the chamber end  8  forms a closure at the distal end of the syringe barrel. An elongated hollow passage or cannula  9  is shown formed in the chamber end and wherein the cannula  9  extends from the medication chamber  5  to the needle carriage  15 .  
         [0025]    A plunger  2  is shown inside the syringe barrel  7 . The plunger has a plunger gasket  3  at the distal end of the plunger and a thumb flat  4  at the proximal end of the plunger. The plunger gasket  3  forms a fluid tight and gas tight seal around the inside surface of the syringe barrel  7 . To actuate the plunger the thumb flat is depressed, thereby thrusting the plunger gasket in the distal direction  17  thereby creating pressure in the medication chamber  5 , and further forcing the medication into syringe barrel cannula  9 , past the carriage seal  10 , into the carriage cannula  11 , into the needle cannula  12  and into the body  19 .  
         [0026]    The carriage cannula  11  is shown formed in the needle carriage  15  that is shown in the retraction trunk  20 . The retraction trunk  20  is suitably fixed adjacent to the syringe barrel  7 . The retraction trunk preferably has at least one spline  21  formed at the distal end of the retraction trunk  20  wherein at least one spline meshes with at least one groove formed in the distal end of the needle carriage  14  to prevent the needle carriage  15  from rotating while the needle cannula base  23  is being threaded onto the needle carriage.  
         [0027]    A spring ridge or shoulder  24  is shown formed on the inside surface near the distal end of the retraction trunk  20  thereby forming a landing or support for a biased spring  16 . A carriage spring ridge or shoulder  25  is shown near the proximal end of the needle carriage  15  wherein the biased spring  16  further thrusts on the needle carriage. The biased spring  16  is restrained from thrusting the needle carriage into the proximal end of the retraction trunk  20  by a stop bar  26 . Stop bar  26  is shown disposed in a stop hole  27  formed on the outside surface of the needle carriage  15 . The stop bar  26  extends from the stop hole  27 , through the retraction trunk hole  28  (see FIG. 3), where it is rotatably fixed to the first end of the retraction lever  30 . The retraction lever  30  is further rotatably fixed to the retraction fulcrum  29  near the second end of the retraction lever. The retraction lever  30  is depressed with a finger or a thumb thereby withdrawing the stop bar  26  out of the stop hole  27 . The withdrawal of the stop bar  26  releases the needle carriage  15  and allows the biased spring  16  to thrust the needle carriage  15  into the proximal end of the retraction trunk  20 .  
         [0028]    As the plunger  2  is depressed, the plunger gasket  3  causes an increase in pressure in the medication chamber  5 , thereby forcing medication (not shown) or other fluid or gas into the syringe barrel cannula  9 , into the carriage cannula  11 , into the needle cannula  12 , and into a body  19 . The carriage seal  10  forms a fluid tight and gas tight seal between the syringe barrel  7  and the needle carriage  15 . In a retracted position, a carriage stop  31 , formed on the inside surface of the retraction trunk  20 , will catch and hold the needle carriage once the needle carriage  15  is released into the retraction trunk.  
         [0029]    [0029]FIG. 2 is an enlarged section elevation of the distal end of the syringe  1  illustrating the locking mechanism between the needle carriage  15  and the retraction trunk  20 . The needle carriage  15  has splines  14  which mesh with the splines  21  of the retraction trunk  20 . The anti-rotation splines of the needle carriage  15  are shown preventing the needle carriage  15  from rotating while the needle cannula base  23  is being fastened to the needle carriage. A fluid tight seal is shown formed between the carriage cone  32  and the needle cannula foundation  33 . This sealing method is commonly referred to as Luer-Lok® (Becton Dickinson, Franklin Lakes, N.J.) in the syringe manufacturing industry. A snap-on fitting or a slip-on fitting could also be used. Furthermore, the stop bar  26  is shown suitably disposed in the stop hole  27  formed in the needle carriage  15 .  
         [0030]    [0030]FIG. 3 is shown a section elevation of the syringe  1  as taken through FIG. 1 illustrating the latching means between the needle carriage  15  and the retraction trunk  20 . The first end of the stop bar  26  is shown disposed in the stop hole  27  formed in the outside surface of the needle carriage  15 . The center section of the stop bar is shown suitably disposed in the retraction trunk hole  28  formed in the retraction trunk  20 . The retraction trunk hole  28  extends from the inside surface to the outside surface of the retraction trunk.  
         [0031]    The syringe barrel cannula  9  is shown essentially near the center of the syringe barrel  7 . The syringe barrel cannula  9  is shown extending from the syringe barrel  7  into the retraction trunk  20  where it is suitably connected to the carriage cannula  11  formed inside of the needle carriage  15 .  
         [0032]    [0032]FIG. 4 is an enlarged section plan view as taken through FIG. 1 illustrating the seal between the plunger gasket foundation  35  and the syringe barrel  7 . The plunger gasket foundation  35  is shown essentially in the center of the syringe barrel  7 . The plunger  2  is shown with cross members  36 . Although cross members are shown, the plunger could have a cylinder or some other section instead by design choice. Furthermore, the syringe barrel  7  is shown formed or coupled with the retraction trunk  20 . The syringe barrel  7  and the retraction trunk  20  could also be bonded by glue or adhesive by design choice. The needle carriage  15  is shown essentially centered within the retraction trunk.  
         [0033]    [0033]FIG. 5 is a section elevation of the syringe  1  in a retracted position. The retraction lever  30  has been depressed in direction  37 , thereby withdrawing stop bar  26  from the stop hole  27  formed in the needle carriage  15 . This releases the needle carriage from the stop bar, allowing the biased spring  16  to thrust the needle carriage toward the proximal end of the retraction trunk  20 , thereby drawing the needle cannula  12  into the inner confines of the retraction trunk  20 . Once inside the retraction trunk, the needle carriage  15  will be caught by the carriage stop  31  and will be retained within the confines of the retraction trunk  20  wherein the now contaminated needle cannula will be unable to prick or otherwise injure a person. Furthermore, the device  1  is shown after medication has been injected into a body, and the plunger has been completely depressed.  
         [0034]    [0034]FIG. 6 is a section elevation of a multi-syringe barrel syringe  38  having a first syringe barrel  39  and second syringe barrel  40 . Although there are two syringe barrels shown, there could also be more than two syringe barrels by design choice. Although there is only one retraction trunk shown, there could also be more than one retraction trunk by design. The first syringe barrel is shown with a first plunger  41 , a first plunger seal  42 , and a first thumb flat  43 . The second syringe barrel is shown with a second plunger  44 , a second plunger seal  45 , and a second thumb flat  46 . The first and second thumb flats are shown as not being connected to allow one plunger to be depressed independently of the other plunger. A first trunk cannula  47  is shown extending from the first syringe barrel  39  to a carriage manifold  49  formed inside of the carriage  50 . A second trunk cannula  48  is shown extending from the second syringe barrel  40  to the carriage manifold  49 . A first O-ring  57  is shown forming a gas and fluid tight seal between the first trunk cannula and the carriage manifold. A second O-ring  58  is shown forming a gas and fluid tight seal between the second trunk cannula and the carriage manifold.  
         [0035]    A biased spring  51  is shown disposed between the outside surface of the carriage and the inside surface of the retraction trunk  59 . The first end of the biased spring  51  is also disposed on the retraction trunk ridge  60  and the second end of the biased spring is disposed on the carriage ridge  61  formed on the outside surface of the carriage. The biased spring is disposed in a manner to thrust the carriage with the needle cannula into the proximal end of the retraction trunk. In addition, a latch extension  55  is shown extending from the carriage  50 . The latch means  56 , which will be described in greater details in FIG. 9, secures the carriage in place prior to retraction.  
         [0036]    [0036]FIG. 7 is a section plan view of the latch release means  56  as taken through FIG. 6. In FIG. 7, the first plunger  41  is shown disposed in the first syringe barrel  39  and the second plunger  44  is disposed in the second syringe barrel  40 . Both syringe barrels are shown fixed to the retraction trunk  59 .  
         [0037]    The latch means  56  is shown restraining the latch extension  55  which in turn restrains the carriage  50  (not shown in this view). A latch extension tab  66  is shown positioned in a latch slot  64  and a latch ridge  63  at the proximal end of the latch extension  55  is shown being retained by the latch means  56 . A button  67  is shown at the distal end of the latch means  56  and a latch opening  65  is shown near the inner end of the latch means  56 . Depression of the button  67 , by a finger or thumb in an inward direction  62 , causes the latch opening to be thrust around the latch extension  55  thus releasing the latch extension and the carriage.  
         [0038]    [0038]FIG. 8 is a section elevation of the multi-syringe barrel syringe  38  in a retracted position. The figure depicts the latch means  56  as having been depressed, thus releasing the latch extension  55  to move within the retraction trunk  59  in the proximal direction  72 . The depression of the latch means  56  allows the biased spring  51  to thrust the carriage  50  with the needle cannula  52  into the retraction trunk  59 . Inside the retraction trunk, the point  70  of the needle cannula is sheltered, thereby preventing an accidental needle stick or pricking of others. In addition, the first plunger  41  and the second plunger  44  are shown completely depressed. However, the syringe preferably accommodates either the depression of one or both of the plungers at the user&#39;s discretion.  
         [0039]    [0039]FIG. 9 is a section plan view of the syringe  38  as taken through FIG. 6 with the button  67  in a depressed position. The depression of the button  67  thrusts the latch means  56  off of the latch ridge  63  of the latch extension  55 . Furthermore, depression of the button  67  also forces the latch bars  68  off of the latch extension  55  and the latch ridge  63  ( see FIG. 7) and thereby releasing the latch extension.  
         [0040]    Although the invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art, that additions, modifications, substitutions, deletions and other changes not specifically described, may be made in the embodiment herein. It should be understood that the details herein are to be interpreted as illustrations and are not in a limiting sense.