Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/178—Syringes
  • A61M5/31—Details
  • A61M5/32—Needles; Details of needles pertaining to their connection with syringe or hub; Accessories for bringing the needle into, or holding the needle on, the body; Devices for protection of needles
  • A61M5/3205—Apparatus for removing or disposing of used needles or syringes, e.g. containers; Means for protection against accidental injuries from used needles
  • A61M5/321—Means for protection against accidental injuries by used needles
  • A61M5/322—Retractable needles, i.e. disconnected from and withdrawn into the syringe barrel by the piston
  • A61M5/3234—Fully automatic needle retraction, i.e. in which triggering of the needle does not require a deliberate action by the user

Definitions

• the present invention relates to a so-called disposable hypodermic syringe or a self- destructing hypodermic syringe, of the type which comprises a syringe housing, a plunger with plunger rod and plunger head with associated seal, and an injection needle.
• the syringe is of the type that is destroyed during use, and which can be disposed of without any problems as the syringe needle is retracted into the syringe housing on destruction.
• hypodermic syringes are unfortunately used extensively and repeatedly by "mainliners”, addicts who take drugs by injection, and it is in connection with this category of users that major problems have arisen with the reuse of syringes and even of so-called conventional disposable syringes.
• the object of the present invention is to make a contribution to an improved situation, and accordingly it relates to a self-destructing disposable syringe comprising a syringe housing, a plunger with plunger rod and plunger head with seal, and an injection needle, and this syringe is characterised by - an extension running from the external end wall of the housing and equipped with inwardly bendable flaps; a holder located centrally in the housing having a central bore and having a flange formed at the end facing the plunger head having a liquid-tight seal against the liquid chamber of the housing; and having - a wholly or partly tapered part extending inside the flapped extension of the housing and having an end bead with an inverted collar for interaction with and retention of the inwardly bent flaps on the extension of the housing; having an injection needle running through the bore of the holder, an end sleeve which is coaxial with and
• the syringe of the invention is based on the principle that locking means are released the instant the syringe is emptied of its contents on injection so that the whole element holding the hypodermic needle is retracted into the syringe housing without later being capable of being locked in a forward position.
• Figure 1 shows a syringe ready for use and where two different possibilities are indicated for retraction of the needle
• Figure 2 shows a syringe containing aspirated injection liquid immediately prior to injection
• - Figure 3 shows the situation after the injection has been completed, where the syringe is empty and the locking means have been released
• Figure 4 shows the empty, destroyed syringe with retracted injection needle
• Figure 5 shows an alternative embodiment having chemical means for driving back the needle holder
• Figure 5a shows an alternative embodiment with a sealing ring 24 disposed around the needle holder 8
• Figure 5b shows schematically the flaps 6 on the extension 7.
• Figure 6 corresponds to Fig. 4.
• Figure 1 shows a syringe having syringe housing 1 , plunger with plunger rod 2 and plunger head 3 with seal 3 ' and having an injection needle 4.
• An injection needle holder 8 having a central bore 9 for the injection needle is provided in the distal end of the syringe.
• this holder is equipped with a flange 10 having a liquid seal 11 against the liquid chamber 12 of the housing 1.
• This flange that is the surface facing the liquid chamber, serves as effective bottom of the syringe.
• the holder is equipped with a conical tapered part 15 which moves into the extension 7 of the housing 1.
• the flaps 6 of the extension 7 are bent inwards in intimate contact with the conical tapered part 15, and the flaps are locked in the inwardly bent position by means of a locking groove under an inverted collar 17 on an end bead 16 on the cone 15. It can be noted from Figure 1 that there is a small space between the distal end of the end bead 16 and the internal surface of the end wall of the end sleeve 22, a fact which is of great importance as will be explained below.
• Fig. 1 The position shown in Fig. 1 is the starting position for the use of the syringe.
• the syringe needle is inserted into a capped phial and injection liquid is aspirated into the liquid chamber 12 of the syringe as indicated in Fig. 2.
• the holder with injection needle 4, and also with plunger head and plunger rod can be pressed into the syringe with the aid of suitable means.
• these means are formed by a helical spring 18 which on one side rests against the flange 10 on the holder 8 and at the other end rests against the internal 19 surface of the end wall 5 of the housing.
• the spring is preferably of such strength and size that the one shown in Fig. 4 in a safe manner pushes the holder 8 so far inside the housing that the injection needle 9 passes the end wall of the end sleeve 22, and allows the safety valve 23 to fall into place and prevent the needle 4 from being unintentionally pressed out again.
• Figure 5 shows an alternative embodiment where the holder 8 in the housing 1 is equipped with a flange 10, and where between the flange 10 and the internal surface 19 of the end wall 5 of the housing a chemical propellant is provided as agent for retraction of the holder.
• this agent is intended to be a layer of crystalline formic acid and calcium carbonate and/or another similar compound, which on the penetration of moisture emits CO 2 .
• the retention of the holder 8 takes place in this case by means of two flaps 6, punched out in the extension 7, and pressed down in corresponding grooves which are milled or turned out on the holder 8.
• Figure 5a shows an alternative embodiment with a sealing ring 24 disposed around the needle holder 8.
• FIG. 5b shows schematically the flaps 6 on the extension 7.
• Figure 6 shows the situation after the gas has pressed the holder 8 inside the housing and thus drawn the needle 4 into the extension 7.
• the end extension 7 and the end sleeve 22 are made in one piece.
• the invention is not limited to the retraction means of the illustrated embodiments, it is also conceivable that there may be used, for example, glass ampoules containing propellant gas under pressure and which are crushed after the injection has been completed.
• a further safety feature is indicated in the present figures in that on the plunger head 3 a sleeve 20 is provided having ribs running along the periphery, intended for interaction with a bore 13 in the flange 10 on the holder 8, with corresponding ribs 14, and where the sleeve and recess engage when the injection is complete and the plunger head comes to rest against the surface of the flange (10) facing the liquid chamber.
• the self-destructing disposable syringe of the application provides a safe and relatively simple aid for those who are dependent upon regular injections and who are capable of injecting themselves, as it is also ensured that the aid, the syringe according to the invention, can be disposed of in a non-dangerous manner without there being any risk of unintentional or illegal use since the syringe becomes useless after use.

Landscapes

• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Heart & Thoracic Surgery (AREA)
• Vascular Medicine (AREA)
• Anesthesiology (AREA)
• Biomedical Technology (AREA)
• Environmental & Geological Engineering (AREA)
• Hematology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Infusion, Injection, And Reservoir Apparatuses (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19900361

Family Applications (1)

Country Status (3)

Cited By (8)

Citations (2)

• 1997
  • 1997-02-07 NO NO970576A patent/NO305106B1/no not_active IP Right Cessation
• 1998
  • 1998-02-06 WO PCT/NO1998/000042 patent/WO1998034659A1/en active Application Filing
  • 1998-02-06 AU AU60069/98A patent/AU6006998A/en not_active Withdrawn

Patent Citations (2)

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