Abstract:
A retractable safety syringe that retracts the needle cannula into the plunger module and destroys the syringe to prevent reuse or an accidental needle prick by destroying the plunger barrier and the cannula barrier within the syringe. The needle cannula is released into the plunger module by shearing the cannula barrier and plunger barrier with an internal annular shear and cutter head. The needle cannula module may be replaced with a layer or smaller needle cannula module thereby allowing a greater selection of needle cannulas.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a single use syringe for injecting medicine into a patient. More particularly, the invention relates to a safety syringe having a retractable needle cannula that renders the needle cannula harmless after it is used. 
     2. Background of the Related Art 
     Many communicable diseases can be spread through the penetration or another having a disease previously used scratching of the skin by a needle that. Spreading of the disease in this manner may occur by accident, such as with medical personnel making injections, or it may occur through misuse, such as by intravenous drug users using a previously used needle cannula. 
     Various syringes have been invented, designed and developed to retract the needle into the syringe or the plunger inside of the syringe. Some of these devices are 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), and U.S. Pat. No. 6,010,468 (Carter et al). These designs have needles that retract at the end of the injection. Most of these designs have not reached the market due, at least in part, to problems associated with expense of manufacturing, poor reliability or user acceptability. However, even though some of these designs operate poorly and are costly, they have still been commercialised due to the great need in hospitals or clinics for any type of safety syringe. 
     Most of the existing safety syringe designs allow for automatic retraction of the needle cannula into the plunger barrel of the syringe when the plunger is fully extended into the syringe. The automatic retraction is triggered when the plunger makes physical contact with the distal end of the syringe barrel. Typically, the end of the plunger is provided with a disengageable or sacrificial member at the distal end and the needle cannula is secured by a disengageable or sacrificial member. When the plunger reaches the fully extended position, the physical contact between the plunger and the needle cannula causes activation of the two respective disengageable or sacrificial members. In this manner, the end of the plunger barrel is opened and presented to receive the needle cannula. The needle cannula, no longer secured in position, is biased into the plunger barrel by a spring. 
     Conventional syringes are typically available in modular systems or kits in which approximately ten different sizes of syringes and approximately ten different sizes of needle cannulas can be used interchangeably. This allows an inventory of twenty items to be used in approximately 100 different combinations in accordance with the present need. However, the safety syringes presently available and described in the above patents are not modular and require stocking of an integral safety syringes for each combination of syringe size and needle cannula size desired, for example 100 different safety syringes. Particularly, in light of the greater cost these syringes, the cost, distribution and storage of safety syringes is much greater than conventional syringes. 
     Despite the prevalence of modular convention syringes, the emergence of a multitude of safety syringe designs and the increasing public outcry for safety syringes, the complexities of the safety syringe mechanisms have limited the number of attempts to design a safety syringe that is modular. Two such attempts include modular syringe tip designs that are combined with a conventional syringe as described in U.S. Pat. No. 5,891,093 (Dysarz), U.S. Pat. No. 5,935,113 (Dysarz). Compared with the foregoing automatically retracting safety syringes, these two designs can be considered to have safety needle cannula assemblies that are self-contained and manually operated, while being connectable to a conventional syringe and with a conventional locking arrangement. While these devices serve the aforementioned need for modularity, the obvious drawbacks to the devices include the manual retraction mechanism and the additional length that the needle cannula assembly adds to the syringe. 
     Another design utilises a modified luer-lok that requires pressed fittings, a cutting ring, and a frangible portion that are to be activated or actuated at the same time requiring more hand and finger strength of the user which many medical people do not have. Still another problem with this design is that the needle cannula must be pushed and moved in the direction of the distal end of the needle cannula and if the needle cannula is in an artery or a vein at the time, the needle cannula will pierce the other side of the artery or vein and deposit medication into an undesirable area of the body. Still yet another problem with this design, the plunger tip must enter a restricted area of the luer-lok and restrict and trap the medication still contained in the area of the stopper. And still yet another problem with this design is that when the outer hub is being attached to the luer-lok, the proximal end of the inner hub could be hit by the distal end of the luer-lok fitting and cause the frangible portion to break or otherwise fail. 
     Each of the foregoing designs has various disadvantages. There are parts that work in a difficult and complicated manner and could be expensive to manufacture. These designs could also be difficult to operate. 
     The need exists for a safe and disposable syringe that also cannot be reused and still use standard needle cannula of any verity. 
     SUMMARY OF THE INVENTION 
     It is the object of the present invention to provide a safety syringe module with a safety needle cannula module wherein the safety syringe module reacts with the safety needle cannula module in such a manner that will cause the needle cannula to retreat into the safety syringe module. 
     Another object of the present invention is to render the needle cannula useless after the needle cannula is retracted into the syringe module to prevent the accidental reuse of a contaminated needle cannula or to further prevent the reuse by users of illicit drugs. 
     It is still yet another object of the present invention to allow a hospital or clinic etc., to keep a lesser inventory of safety syringes and safety needle cannulas. 
     The present invention, in at least certain embodiments, provides a syringe with a syringe body with a syringe channel there through, needle cannula apparatus connected to the syringe body with a cannula body and a cannula channel there through, a needle with a needle channel there through and a needle flange at one end, a plunger movably disposed in the syringe channel for pushing fluid in the syringe channel and out through the needle channel, the plunger having a plunger channel there through, a cannula barrier, the needle flange abutting the cannula barrier, the cannula barrier initially preventing the needle cannula from moving into the syringe body, the cannula barrier having a cannula barrier channel there through, a cutter head on the plunger, and a cutter head channel there through, a plunger barrier adjacent the cutter head and initially closing off the plunger interior to fluid, the plunger barrier movable with the cutter head within the syringe body, and the cutter head movable by moving the plunger to break the plunger barrier and the cannula barrier to free the needle cannula so the needle cannula is movable through the cutter head and into the plunger channel. In certain aspects, an optional spring apparatus in the cannula channel urges the needle cannula into the plunger channel upon breaking of the cannula barrier and the plunger barrier. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a section elevation view of the safety needle cannula module and safety syringe plunger module. 
     FIG. 2 is a section plan view as taken through FIG. 1 
     FIG. 3 is a section plan view that is taken through FIG. 1 
     FIG. 4 is an enlarged section elevation of the distal end of the safety needle cannula module and the safety syringe and plunger module. 
     FIG. 5 is an enlarged section elevation showing the plunger module moving towards the safety needle cannula module. 
     FIG. 6 is an enlarged section elevation of the plunger module interacting with the safety needle cannula module. 
     FIG. 7 is an enlarged section elevation of the biased spring thrusting the needle cannula into the plunger module. 
     FIG. 8 is a section elevation of the needle cannula contained in the plunger module. 
     FIG. 9 is a section elevation of the plunger module and the needle cannula module with a latch and retainer means. 
     FIG. 10 is a section elevation showing the latch and the retainer engaged. 
     FIG. 11 is a section elevation with an inverted cutter head. 
     FIG. 12 is a section elevation describing how the inverted cutter head operates. 
     FIG. 13 is a section elevation of a springless syringe. 
     FIG. 14 is a section elevation of the springless syringe being destroyed. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring To FIG. 1 there is shown a section elevation of the syringe  2  with the needle cannula module  1  that is fixed to a syringe body  34 . 
     The syringe body  34  is an elongated hollow tube with an inside surface and an outside surface. The distal end of the syringe body has syringe module threads  13  formed on the outside surface. The proximal end of the syringe body has a finger flat  17 . 
     The needle cannula module  1  is comprised of a needle cannula  11  with the distal end having a point and a proximal end fixed to a needle cannula flange  19 . A cannula tunnel  10  is formed in the needle cannula module that extends from the distal end to the proximal end. The proximal end of the needle cannula  11  is further disposed in a biased spring  5 . The distal end of the biased spring is abutting and thrusting or urged against the cannula flat  16  and the proximal end of the biased spring is thrusting against the distal end of the needle cannula flange. The needle cannula is also shown disposed in the cannula tunnel  10 . The biased spring  5  is also shown disposed in the annular spring guide  15 . 
     The barrier cannula  6  is shown with an annular recess and is suitably fixed to the proximal end of the needle cannula module  1  forming a fluid tight and gas tight seal between the proximal end of the needle cannula module and near the distal end of the syringe body  34 . The outer periphery of the barrier cannula also forms the needle cannula module gasket  20  or seal. The needle cannula module gasket project outwardly into the recess  37  formed between the syringe body and the needle cannula module. The barrier cannula  6  is made out of a shearable or cuttable material. 
     The plunger module  3  is shown disposed in the elongated hollow barrel of the syringe body  34 . The proximal end of the plunger module  3  is shown with a thumb flat  18  and a plunger lock  12  on the outer periphery of the thumb flat. The thumb lock  12  locks onto the finger flat  17 . The plunger module has an elongated tunnel that extends from the distal end to the proximal end or the plunger module. 
     The distal end of the plunger module is suitably fixed to the annular shear foundation  23 . The distal end of the annular shear foundation is fixed to the proximal end of the annular shear and cutter head  4 . The distal end of the annular shear and cutter head  4  is formed into a cutting edge for cutting and shearing the plunger barrier  7  and the barrier cannula  6 . The annular cone shear and cutter head  4  is supporting the plunger barrier  7  that is made out of a shearable material. The plunger barrier  7  is shown partially supported by the annular cone shear and cutter head and the plunger gasket  8 . The plunger gasket  8  is supported on the outer surface of the annular shear foundation. The plunger module and the plunger gasket thrust fluid through the syringe body and into the needle cannula for expulsion from needle cannula. 
     The needle cannula module  1  is fixed to the syringe body  34  by the module threads  13  and the cannula module threads  14 . This could also be a slip on or friction connection or it could be a snap on connection by design choice. 
     Referring to FIG. 2 there is shown a section plan view of the barrier cannula  6  as taken through FIG.  1 . The cannula  22  is shown essentially near the center of the barrier cannula. The needle cannula flange  19  is shown behind the barrier cannula. The outer periphery of the barrier cannula is the needle cannula module  1  and the syringe body  34 . 
     Referring To FIG. 3 there is shown a section plan view of the plunger barrier  7  as taken through FIG.  1 . The syringe body  34  is shown at the outer periphery, the plunger gasket  8  and the annular cone shear and cutter head  4  are shown toward the center of the plunger barrier. 
     Referring to FIG. 4 there is shown an enlarged section elevation of the distal end of the syringe  2  and the entire needle cannula module  1   
     The needle cannula  11  is extending from the cannula tunnel  10  and the proximal end of the biased spring  5  is abutting, thrusting and urging on the distal end of the needle cannula flange  19 . The distal end of the biased spring is abutting, thrusting and urging on the cannula flat  16 . The barrier cannula  6  is sufficiently rigid to retain the biased spring. The barrier cannula  6  is also shown with a barrier recess  37  formed in the proximal end of the barrier cannula. The plunger barrier  7  has a plunger projection  38  wherein the plunger projection conforms with the barrier recess so that medication fluid is not wasted when the barrier recess comes in contact with the plunger projection and the cannula  22  is also closed off to stop fluid flow to the needle cannula. The annular shear and cutter head depository  21  is shown formed in the proximal end of the needle cannula module  1  to allow the annular shear and cutter head  4  sufficient space to complete the shearing or cutting process. 
     The plunger barrier  7  is shown at the distal end of the annular shear and cutter head  4 . 
     Referring to FIG. 5 there is shown a section elevation of the annular cone shear and cutter head  4  moving in a distal direction  24 . The plunger barrier  7  is shown pushed into the barrier cannula  6  thereby blocking the cannula  22  after all medication has been injected into a body. 
     Referring to FIG. 6 There is shown a section elevation view of the annular cone shear and cutter head  4  moving in a distal direction  24  after having sheared or cut a tunnel in the plunger barrier  7  and the barrier cannula  6  thereby releasing the needle cannula  11  and the biased spring  5 . It should be noted that FIG. 6 will be as shown for just a brief moment. 
     The annular shear and cutter head is shown in the annular shear and cutter head depository  21 . 
     Referring To FIG. 7 there is shown a section elevation view of the biased spring  5  thrusting or urging on the distal end of the needle cannula flange  19  and thrusting the needle cannula  11  into the tunnel inside of the plunger module  3 . 
     Part of the barrier cannula  6  and part of the plunger barrier  7  are shown being thrust into or falling to the inside of the plunger module  3  in a proximal direction  25 . The remainder of the barrier cannula  6  and the plunger barrier  7  are shown bent or curved in or near annular shear and cutter head depository  21 . The plunger gasket  8  has been moved in a proximal direction  25  relative to the annular shear foundation  23  that is part of the distal end of the plunger module  3 . 
     Referring to FIG. 8 there is shown a section elevation of the needle cannula module  1  fixed to the syringe body  34  and plunger module  3  with the needle cannula  11  secure inside of the plunger module tunnel. Part of the barrier cannula  6  and the plunger barrier  7  are contained in the plunger module tunnel. 
     The plunger lock  12  is shown latched onto the finger flat  17  thereby locking the plunge module to the syringe body  34  to prevent the plunger from being accidentally pulled out and exposing the needle cannula. 
     Referring to FIG. 9 there is shown an enlarged section elevation of the device of the preferred embodiment with an internal locking means. 
     The internal locking means is comprised of a circumferential latch  27  that is formed on the outside perimeter of the cannular hub  36 . The slipover retainer member  28  is shown formed on the inside surface of the annular shear and cutter head  4 . The slip over retainer member  28  is positioned for engaging the circumferential latch  27  on the cannular hub  36 . 
     Referring to FIG. 10 there is shown a section elevation of the internal locking means engaged. The needle cannula  11  is being thrust into the plunger module  3  by the biased spring  5  thrusting on the needle cannula flange  19 , part of the plunger barrier  7 , and part of the barrier cannula  6  inside of the plunger module  3 . 
     The proximal end of the slip over retainer  28  has been pushed past the distal end of the circumferential latch  27  and thus snapped over the circumferential latch  27  thus locking the slip over retainer to the circumferential latch thereby engaging and locking the plunger module  3  to the needle cannula module  1 . 
     By providing a locking fitting, an internally destroyed syringe and the completely encapsulated needle cannula the entire syringe is destroyed and cannot be reused again. The plunger gasket  8  is shown having been moved in a proximal direction  25  relative to the distal end of the plunger module  3 . 
     Referring to FIG. 11 there is shown a section elevation view of the syringe  2  with the needle cannula module  1  suitably fixed to the syringe body  34  with a plunger module  3  inside of the syringe body  34 . All of the components such as the needle cannula  11 , the cannula tunnel  10 , the cannula flat  16 , the annular cutter head depository  21 , are all similar to FIG.  1 . 
     The inverted cutter head  29  is shown disposed about the annular cutter head foundation  30  and the cutter head flange  31 . The inverted cutter head is shown supported on the proximal end of the annular cutter head foundation  30 . The cutter head flange  31  is shown formed on the outer periphery of the annular cutter head foundation. The invented cutter head is shown with the sharp edge  32  directed toward the barrier cannula  6 . 
     The partial biased spring  35  is shown thrusting or urging the needle cannula flange  19  and the needle cannula  11  into the barrier cannula  6 , however the partial biased spring  35  is shown as partially compressed with gaps between the coils to allow the partial biased spring to be further compressed thereby allowing the needle cannula flange  19  to be moved in a distal direction  24 , thereby exposing the sharp edge  32  of the inverted cutter head  29  to the barrier cannula and the plunger barrier  7  on the distal end of the plunger module  3 . The partial biased spring does not have sufficient thrust or force to push or urge the needle cannula flange past the barrier cannula  6 . 
     The distal end of the plunger module  3  is shown moving in a distal direction  24 . The plunger barrier support flange  33  is shown supporting the plunger barrier as the plunger module is urged in a distal direction  24 . A needle cannula passage  38  is shown formed in the distal end of he plunger module  3 . 
     Referring to FIG. 12 there is shown a section elevation of the second device of the preferred embodiment being internally destroyed. The plunger barrier support flange  33  has thrust the plunger barrier  7  and the barrier cannula  6  into the inverted cutter head  29  and the needle cannula flange  19 . The needle cannula flange  19  has moved in a distal direction  24  further compressing the partial biased spring  35  thereby exposing the barrier cannula  6  and the plunger barrier  7  to the sharp edge  32  of the inverted cutter head  29  and urging the barrier cannula and plunger barrier onto the sharp edge of the inverted cutter head wherein the inverted cutter head  29  has cut a passage or tunnel through the barrier cannula and the plunger barrier thus allowing the partial biased spring  35  to thrust the needle cannula flange  19  and the needle cannula  11  in a proximal direction  25  into the inside of the plunger  3  where the needle cannula  11  will be completely covered to prevent an accidental needle stick. 
     The plunger barrier support flange  33  has been thrust past the inverted cutter head and has been further locked onto the distal end of the cutter head flange  31  wherein the inverted cutter head has been moved through the cannula passage where it will be captured in the distal end or tunnel of the plunger module  31 . 
     Referring to FIG. 13 there is shown a section elevation view of the syringe  2  with the needle cannula module  1  suitably fixed to the syringe body  34  with a plunger module  3  inside of the syringe. Most of the components such as the needle cannula  11 , the cannula tunnel  10 , and the plunger module  3  the plunger barrier  7  and the annular shear and cutter head depository  21  are similar to FIG.  11 . 
     The inverted cutter head  29  is shown disposed about the annular cutter head foundation  30  and the cutter head flange  31 . The inverted cutter head is shown supported on the proximal end of the annular cutter head foundation  30 . The cutter head flange  31  is shown formed on the outer periphery of the annular cutter head foundation. The inverted cutter head is shown with the sharp edge  32  directed toward the barrier cannula  6 . The barrier cannula  6  is holding the needle cannula  11  and the needle cannula flange  19  in place with adhesive or the barrier cannula and the needle cannula flange could be one piece. 
     The distal end of the plunger  3  is shown moving in a distal direction  24 . The plunger barrier support flange  33  is shown supporting the plunger barrier as the plunger module is urged in a distal direction  24 . A needle cannula passage  38  is shown formed in the distal end of the plunger  3 . 
     Referring to FIG. 14 there is shown a section elevation of the second device of the preferred embodiment being internally destroyed. The plunger barrier support flange  33  has thrust the plunger barrier  7  and the barrier cannula  6  into the inverted cutter head  29  and the needle cannula flange  19 . The needle cannula flange  19  has moved in a distal direction  24  thereby exposing the barrier cannula  6  and the plunger barrier  7  to the sharp edge  32  of the inverted cutter head  29 . As the plunger module further moves in a distal direction the plunger barrier support flange  33  urges or thrusts the barrier cannula and the plunger barrier onto the sharp edge of the inverted cutter head wherein the inverted cutter head  29  cuts or shears a passage through the barrier cannula and the plunger barrier thus allowing the needle cannula  11  to fall in a proximal direction  25  into the inside of the plunger  3  where the needle cannula  11  will be completely covered to prevent an accidental needle stick. 
     The plunger barrier support flange  33  has been thrust past the inverted cutter head and has been further locked onto the distal end of the cutter head flange wherein the inverted cutter head has been moved through the cannula passage  38  where it will be captured in the distal end of the plunger module  3 . 
     The present invention, therefore, provides in certain, but not necessarily all embodiments, a syringe with a syringe body with a first body end and a second body end and a syringe channel there through from the first body end to the from the first body end to the second body end, needle cannula apparatus connected to the syringe body and with a cannula body having a first cannula end and a second cannula end, and a cannula channel extending from the first cannula end to the second cannula end, a needle having a first needle end and a second needle end, the first needle end projecting from and extending beyond the cannula body, the second needle end within the cannula channel, the needle having a needle channel there through from the first needle end to the second needle end, the needle having a needle flange at the second needle end, a plunger with a first plunger end and a second plunger end, the first plunger end movably disposed in he syringe channel for pushing fluid in the syringe channel to and through the needle channel for expulsion out from the first needle end, the plunger having a plunger channel from the first plunger end to the second plunger end, a cannula barrier connected to the cannula body and extending across the second cannula end, the needle flange abutting he cannula barrier, the cannula barrier initially preventing the needle cannula from moving into the syringe body, the cannula barrier having a cannula barrier channel there through permitting fluid communication between the syringe channel and the needle channel, a cutter head at the first plunger end and having a first cutter end, a second cutter end, and a cutter head channel there through from the first cutter end to the second cutter end, a plunger barrier adjacent the cutter head and initially closing off the first cutter head movable by moving the plunger to break the plunger barrier and the cannula barrier to free the needle cannula so the needle cannula is movable through the cutter head and into the plunger channel. Such a method may include one or some (in any possible combination) of the following: spring apparatus in the cannula channel for urging the needle cannula into the plunger channel upon breaking of the cannula barrier and the plunger barrier; the cannula channel having a top edge, and the spring apparatus including a spring with a first spring end abutting and urged against the top edge of the cannula channel and a second spring end abutting and urged against the needle flange; wherein the spring is movable into the plunger channel; the cannula barrier having a recess, the cannula body having a cannula lip projecting inwardly and disposed in the recess; wherein the cannula body has an interior circumferential channel, the cutter head having an upper cutting edge sized and configured for receipt within the interior circumferential channel and for facilitating breaking of the plunger barrier and the cannula barrier by the cutter head; wherein the cannula barrier has a cannula barrier lip seal disposed between a lower edge of the cannula body and an upper shoulder of the syringe body; wherein the cannula barrier has a barrier recess formed in a bottom surface hereof and the plunger barrier has a plunger projecting portion projecting from a top surface thereof, the barrier recess and the plunger projecting portion each having a corresponding shape for mating abutment of the plunger barrier against the cannula barrier so that fluid flow to the needle channel is closed off upon said abutment, the plunger movable to move the plunger barrier into abutment against the cannula barrier; seal apparatus projecting from the plunger barrier for sealing off a space between an interior surface of the syringe body and an exterior surface of the cutter head, thereby preventing fluid in the syringe body from flowing into said space; wherein an upper portion of the seal apparatus is deformable against the cannula barrier when pushed there against; first locking apparatus for locking the cutter head to the cannula body after the cutter head has broken the plunger barrier and the cannula barrier; wherein the first locking apparatus has a cannula hub within the cannula body defined by a projecting hollow cylindrical body encompassing a portion of the needle cannula, a latch member on an exterior surface of the cannula hub, and a retainer member on the cutter head positioned for engaging the latch member of the cannula hub to lock the cutter head and the plunger connected thereto to the cannula hub preventing movement of the plunger; second locking apparatus for locking the plunger to the syringe body; wherein the second locking apparatus has syringe flange at the second body end, and the plunger with a plunger with a plunger retainer member at the plunger second end, the plunger retainer member movable to engage the syringe flange to lock the plunger to the syringe body; wherein the needle cannula apparatus includes a plurality of cannula bodies each with a needle cannula of a different gauge, each cannula body connectable to the syringe body; and/or the first body end of the syringe body having interior threads, the second cannula end of the cannula body having exterior threads for threadily mating with the interior threads of the first body end of the syringe body to connect the cannula apparatus to the syringe body. 
     The present invention, therefore, provides in certain, but not necessarily all embodiments, a syringe with a syringe body with a first body end and a second body end and a syringe channel there through from the first body end to the second body end, needle cannula apparatus connected to the syringe body and with a cannula body having a first cannula end and a second cannula end, and a cannula channel extending from the first cannula end to the second cannula end, a needle having a first needle end and a second needle end, the first needle end projecting from and extending beyond the cannula body, the second needle end within the cannula channel, the needle having a needle channel there through from the first needle end to the second needle end, the needle having a needle flange at the second needle end, a plunger with a first plunger end and a second plunger end, the first plunger end movably disposed in the syringe channel for pushing fluid in the syringe channel to and through the needle channel for expulsion out from the first needle end, the plunger having a plunger channel from the first plunger end to the second plunger end, a cannula barrier connected to the cannula body and extending across the second cannula end, the needle flange abutting the cannula barrier, the cannula barrier initially preventing the needle cannula from moving into the syringe body, the cannula barrier having a cannula barrier channel there through permitting fluid communication between the syringe channel and the needle channel, a cutter head at the first plunger end and having a first cutter end, a second cutter end, and a cutter head channel there through form the first cutter end to the second cutter end, a plunger barrier adjacent the cutter head and initially closing off the first cutter end, the plunger barrier movable with the cutter head within the syringe body, the cutter head movable by moving the plunger to break the plunger barrier and the cannula barrier to free the needle cannula so the needle cannula is movable through the cutter head and into the plunger channel, first locking apparatus for locking the cutter head to the cannula body after the cutter head has broken the plunger barrier and the cannula barrier, and second locking apparatus for locking the plunger to the syringe body. Such a method may include one or some (in any possible combination) of the following: spring apparatus in the cannula channel for urging the needle cannula into the plunger channel upon breaking of the cannula barrier and the plunger barrier; and/or wherein the needle cannula apparatus includes a plurality of cannula bodies each with a needle cannula of a different gauge, each cannula body connectable to the syringe body.