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  • A61M5/322—Retractable needles, i.e. disconnected from and withdrawn into the syringe barrel by the piston
• • 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  • A61M5/322—Retractable needles, i.e. disconnected from and withdrawn into the syringe barrel by the piston
  • A61M5/3221—Constructional features thereof, e.g. to improve manipulation or functioning
  • A61M2005/3223—Means impeding or disabling repositioning of used needles at the syringe nozzle
  • A61M2005/3224—Means to disalign the needle tip and syringe nozzle

Definitions

• the invention relates to a syringe with a displaceably guided in a housing piston and a retractable into the housing needle.
• Injection syringes for administering medicaments or vaccines are preferably designed as disposable syringes which are to be disposed of after a single use and in which a mechanism ensures that they are unusable after initial use, so that infections by a renewed use of the syringe are avoided.
• a mechanism ensures that they are unusable after initial use, so that infections by a renewed use of the syringe are avoided.
• the unprotected needle of the syringe during or after the disposal leads to injuries and thus to infections.
• it has hitherto been customary to place a protective cap on the needle after use of the syringe, so that the needle is protected in the state of disposal of the syringe. Not infrequently, however, it comes just when attaching the cap to injuries.
• injection syringes are known in which the needle is elastically biased so that it automatically springs back into the interior of the housing after use of the syringe.
• this requires a relatively complex triggering mechanism which increases the production costs for the syringes.
• Disposable syringes for mass vaccinations or to combat endemic diseases, especially in the third world, should, however, be producible as inexpensively as possible.
• the object of the invention is therefore to provide a disposable injection syringe which can be produced at low cost and which offers increased safety.
• the piston and the needle are connected by a coupling which has three states: a releasable coupling state in which the needle with the piston is movable towards the front end of the housing, a disengaged state in which the piston can be moved back into the housing separately from the needle, and a permanent coupling state in which the needle can be withdrawn into the housing with the aid of the piston.
• the clutch In the delivery state of the syringe, the clutch is in the alshebba ⁇ Ren coupling state, and the piston is retracted, so that the needle is protected inside the housing. This reduces the risk of injury before using the syringe.
• the user pushes the piston forward, so that the needle extends out of the housing. Then, as usual, the needle tip can be immersed in the serum or medicament and, by retracting the piston, the fluid can be sucked into the housing of the syringe.
• the clutch is in the disengaged state, so that the needle remains in its extended position with respect to the housing ver ⁇ and the piston moves back alone.
• the piston is then moved forward again, until finally the coupling parts of the piston and the needle again engage each other. In this case, the coupling now changes into the permanent coupling state, in which the needle and piston are permanently connected to one another are.
• the permanent coupling state also has the advantage that the needle can be pulled back into the housing with the aid of the piston, without the user running the risk of injuring himself at the point of the needle. In the disposal state then the needle is again protected inside the case, so that even third parties can no longer hurt or infect the needle.
• the perma ⁇ nente coupling is preferably formed by a tensile locking connection between the needle and the piston.
• a thrust-resistant connection between the piston and needle is made by an elastically biased element, so that the needle can be pushed by the piston forward without the permanent coupling state forming latching connection is made.
• the elastically biased element relaxes, so that now the Rastver ⁇ bond can be made for the permanent coupling state as soon as the coupling elements of the needle and the piston again engage with each other.
• a coupling part formed at the rear end of the needle and the housing of the syringe are designed such that they can be latched to one another in a fluid-tight manner when the needle is in its front end position.
• the needle can be held in its front end position in the housing, and it is ensured that the clutch from the releasable coupling state merges into the disengaged state, when the piston during retraction of the syringe, that is withdrawn during the suction of the liquid ,
• the fluid-tight connection at the same time the construction of a negative pressure in the housing and thus the suction of the liquid allows.
• the detent between the needle and the housing is so dimensioned that the moment of resistance acting on the needle when the needle is inserted into the patient's body is insufficient to release the detent connection, while in the permanent coupling state the detent connection between the needle and the piston is sufficient so strong is that the needle can be released again from its catch on the housing.
• the elastically prestressed element is preferably formed by at least one elastic tongue which, in the pretensioned state, acts as a spacer between the coupling part of the needle and the coupling part of the piston.
• the elastic tongue relaxes upon retraction of the piston, it comes into a position in which it can dive into a recess of the respective other coupling part, so that it no longer acts as a spacer and the production of the locking connection for the permanent Coupling state allows.
• a detent is formed in the interior of the housing in a manner known per se, which forms a stop or pressure point during the retraction of the piston during the mounting of the syringe, so that the piston is not pulled back too far. If after injection the syringe is transferred to the disposal state, however, this pressure point can be overcome with a certain expenditure of force, and the catch then prevents the needle from being moved forward again. This ensures that the needle is permanently protected in the disposal state inside the housing.
• the coupling is designed so that it causes a slight inclination of the needle in the permanent coupling state, so that the needle tip abuts on a shoulder at the front end of the Ge housing and can not be extended out of the housing when they Once withdrawn after the injection process.
• FIGS. 1 to 5 show axial sections through a syringe in various stages before, during and after an injection procedure
• Figure 6 is an enlarged axial section through a coupling between the needle and the piston of the syringe in a lift-off coupling state
• FIG. 7 shows a section through the coupling in a sectional plane rotated in the opposite direction to FIG. 6 in a permanent coupling state of the coupling
• FIG. 8 shows a partial section through a syringe according to a modified embodiment
• FIG. 9 shows a section analogous to FIG. 7 for a modified embodiment of the coupling.
• FIG. 10 shows a section through the syringe with the coupling of FIG. 9 in the disposal state.
• the syringe shown in FIG. 1 has a cylindrical housing 10 made of plastic, which is narrowed at the front end to form a spout 12.
• a detent in the form of a circumferential annular groove 14 is formed in the inner wall of the housing.
• a disk-shaped piston 16 is seated at the front end of a piston rod 18 and is slidably guided in the cylindrical part of the housing 10.
• a needle 20 is in the state shown in Figure 1 in the interior of the housing 10 so that its tip is protected in the spout 12.
• the rear end of the needle 20 is connected to the piston 16 through a coupling 22.
• the coupling 22 has a needle-side coupling part 24 and a piston-side coupling part 26. These coupling parts are in Figure 1 in a cancelable coupling state in which a shear-resistant, but when retracting the piston 16 detachable connection between the piston and needle is created.
• the needle-side coupling part 24 has a circumferential bead 28, which is complementary to the annular groove 14 of the housing 10.
• the state of the syringe shown in FIG. 1 corresponds to the delivery state.
• the user pushes the piston 16 forward by means of the piston rod 18.
• the needle 20 moves out of the housing, and the bead 28 engages in the annular groove 14, so that the needle 20 is fixed by its coupling part 24 with a certain holding force on the housing fi ⁇ .
• a trained on the coupling member 24 cone 30 is then pas ⁇ send in the spout 12, so that the limited by the piston 16 cavity in the front part of the housing 10 is sealed to the front, on the one hand by the abutment of the peripheral wall of the cone 30 on the inner surface the grommet 12 and the other by the engagement of the bead 28 in its annular groove 14. Zu ⁇ same, the needle 20 is held stable in the housing 10 in this way.
• the user retracts the piston rod 18 to the position shown in FIG.
• the coupling parts 24, 26 can disengage, so that the piston 16 moves back alone, while the needle 20 remains locked by the coupling part 24 on the housing 10. Since the cavity 32 in the interior of the housing 10 is sealed in a fluid-tight manner. sen, the liquid to be injected is sucked through the interior of the needle 20 an ⁇ .
• the holding force of the detent formed by the bead 28 and the annular groove 14 is so great that the needle does not recede when stabbed in, but retains its position relative to the housing 10.
• FIG. 6 shows the clutch in the releasable clutch state according to FIG. 1.
• the coupling part 24 has the shape of a bell, which opens in the direction of the piston 16 and whose peripheral wall is interrupted at at least two points by recesses 34.
• a resilient tongue 36 which is formed in one piece with the Kupplungs ⁇ part 24 and extends freely in the direction of the piston 16.
• the tongues 36 are slightly compressed, and they are under elastic bias in a recess 38, for. B. an annular groove of the piston 16. In this state, the tongues 36 act as a spacer between the piston 16 and the coupling part 24.
• the piston-side coupling part 26 is formed directly on the front of the piston and forms a collar, the bell-shaped needle-side coupling part 24 on a part of its circumference surrounds and whose profile has the shape of an inwardly cranked detent 40.
• At the outer circumference of the bell-shaped coupling part 24 corresponding Jacobra ⁇ costs 42 are formed.
• the locking lugs 40 slide only with their ramp on the counter-latches 42 (this happens in a in Fig. 6 not visible remediesssb area), whereby the collar is slightly widened.
• Piston 16 is withdrawn again, so the resilient tongues 36 come out with their free ends from the recess 38, and they spring into a stretched back position in which they are approximately parallel to each other. In this position, the free ends of the tongues 36 are flush with deeper recesses 48 of the piston 16.
• the resilient tongues 36 enter the recesses with their free ends 48, so that they are no longer effective as spacers. The distance between the coupling parts 26 and 24 can therefore be reduced to such an extent that the latching lugs 40 slide over the mating latches 42 and lock behind these mating racks, as shown in another sectional plane in FIG.
• the collar-shaped coupling part 26 and the counter-detents 42 on the coupling part 24 are each formed only on a part of the circumference. In the case of the injection-molded production of the coupling parts, this makes it possible to easily remove the undercuts formed by the latching noses 40 and the counter-catches 42.
• the locking lugs 42 and the counter-detents 40 can be rotated against each other so that they do not touch each other. Subsequently, the needle-side coupling part 24 can be rotated so far about its longitudinal axis that the counterclaims 40 reach a position opposite the latching noses 42.
• a circumferential flat collar 50 is formed on the cylindrical inner wall of the housing 10, which forms a stop for the piston 16.
• the position of the piston is in the state Ausrissaszu ⁇ defined according to Figures 1 and 6.
• the resistance formed by the collar 50 can be overcome with a certain amount of force.
• the collar When mounting the syringe (FIG. 3), the collar then forms a pressure point in the opposite direction, which indicates to the user that the maximum filling volume of the syringe has been reached.
• the injection process can now take place without a pressure point having to be overwintered.
• the piston 16 is then drawn back over the collar 50, so that the piston can then be pushed forward again only with a certain expenditure of force. This reduces the risk that the needle tip exits the spout 12 again.
• FIG. 8 shows an embodiment in which the piston 16 in the condition of delivery (FIG. 1) is fixed between a front collar 50 and a rear collar 52.
• a resilient tongue 54 is formed, which must be locked at the rear end of the housing 10 and depressed by hand in order to transfer the syringe from the state shown in Figure 1 in the state of Figure 2.
• the tongue 54 re-engages behind the end of the housing 10, thus preventing the needle from escaping from the spout 12 of the housing.
• FIG. 9 shows a coupling 22 ', which differs from the coupling 22 according to FIG. 7 in that there is a certain play between the latching lug 40 and the counterstop 42 on one side (bottom in FIG. 9) and the latching lug 40 is supported on the piston 16 via a resilient tongue 56.
• this modification has no effect and the needle 20 is aligned with the spout 12 so that it can extend out of the spout.
• the needle is held coaxially within the spout 12 by the cone 30, and the tongue 56 is resiliently biased.
• the needle 20 is so short that it can be completely withdrawn from the spout 12 when the piston rod 18 is withdrawn.
• the elastic tongue 56 and the play of the lower detent 40 then cause (in conjunction with a certain compliance of the pin 44) that the coupling part 24 and the needle 20 assume the inclined position shown in FIG again advancing the piston rod no longer in the Spout 12 enters, but is retained with its tip on a shoulder 58 on the front wall of the housing ten ren.

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• 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)

Applications Claiming Priority (2)

Publications (1)

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ID=34967689

Family Applications (1)

Country Status (6)

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• 2004
  • 2004-07-22 DE DE202004011516U patent/DE202004011516U1/de not_active Expired - Lifetime
• 2005
  • 2005-05-14 CN CN2005800245474A patent/CN101068587B/zh not_active Expired - Fee Related
  • 2005-05-14 EP EP05742881A patent/EP1771219A1/de not_active Withdrawn
  • 2005-05-14 US US11/572,225 patent/US7637888B2/en not_active Expired - Fee Related
  • 2005-05-14 CA CA2574298A patent/CA2574298C/en not_active Expired - Fee Related
  • 2005-05-14 WO PCT/EP2005/005303 patent/WO2006010393A1/de active Application Filing

Non-Patent Citations (1)

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