Medical Device with Retractable Needle and Moveable Plunger Seal

Patent metadata

Field	Value
Publication number	US-2017239426-A1
Application number	US-201715590556-A
Country	US
Kind code	A1
Filing date	May 9, 2017
Priority date	Jun 30, 2010
Publication date	Aug 24, 2017
Grant date	—

Abstract

A medical device having a barrel, a retractable needle, a needle retraction assembly and a plunger, the needle retraction assembly including and being held inside the barrel prior to retraction at least in part by a retainer member contacting the barrel, the plunger comprising a plunger seal with an body having at least a portion that is rearwardly moveable relative to the plunger and an elastomeric web that seals a retraction cavity inside the plunger prior to retraction of the needle, the retainer member and the plunger seal each cooperating with an inside wall of the barrel to provide a sealed liquid containment chamber inside the device.

First claim

1 . A medical device having a retractable needle, the device comprising:
a barrel; a needle retraction assembly further comprising a needle holder seated inside the barrel and a retainer ring that seals against fluid leakage between the needle holder and the barrel, wherein the retractable needle is attached to the needle retraction assembly and projects forwardly of the barrel; and a plunger inserted into an opening in the rear of the barrel that slidably engages the barrel so as to allow forward movement of the plunger inside the barrel, the plunger further comprising a longitudinally extending sidewall defining an interiorly disposed retraction cavity with a forwardly facing open end, an annular shoulder facing radially outward from the plunger sidewall, and an elastomeric plunger seal disposed at the front of the plunger; the plunger seal further comprising an annular body disposed in spaced-apart relation to the annular shoulder of the plunger that is moveable rearwardly on the plunger sidewall prior to needle retraction, and an elastomeric web that extends across the open end of the retraction cavity and prevents liquid from leaking into the retraction cavity prior to needle retraction.

2 . The medical device of claim 1 wherein the plunger comprises at least one surface that limits how far at the at least part of the annular body can move on the plunger sidewall.

3 . The medical device of claim 1 wherein the plunger has a blunt forwardly facing surface surrounding the forwardly facing open end.

4 . (canceled)

5 . (canceled)

6 . (canceled)

7 . The medical device of claim 1 wherein the elastomeric plunger seal is molded from a rubbery material.

8 . The medical device of claim 1 wherein the retainer ring is molded from an elastomeric material.

9 . (canceled)

10 . The medical device of claim 8 wherein the needle holder has an outside diameter and the sidewall of the plunger has an inside diameter greater than the outside diameter of the needle holder.

11 . The medical device of claim 1 wherein a portion of the needle holder projects forwardly of the barrel prior to needle retraction.

12 . The medical device of claim 1 wherein the needle holder comprises a longitudinally extending fluid passageway and wherein the needle is attached in fixed longitudinal relation to the fluid passageway.

13 . (canceled)

14 . (canceled)

15 . (canceled)

16 . The medical device of claim 1 wherein a forwardly extending part of the plunger causes the plunger seal to contact the retainer ring prior to retraction of the needle.

17 . The medical device of claim 1 wherein the retainer ring is moved forwardly and is displaced from the needle holder by forward movement of the plunger during retraction.

18 . The medical device of claim 16 wherein the annular body of the plunger seal is displaced rearwardly on the plunger after the forwardly extending part of the plunger seal contacts the retainer ring.

19 . The medical device of claim 1 wherein the needle retraction assembly comprises at least one rearwardly projecting structure that is configured to contact and penetrate the elastomeric web extending across the open end of the retraction cavity when the plunger is moved forwardly inside the barrel just prior to needle retraction.

20 . The medical device of claim 1 wherein the needle retraction assembly comprises at least one rearwardly projecting structure that is configured to contact and displace the elastomeric web extending across the open end of the retraction cavity when the plunger is moved forwardly inside the barrel just prior to needle retraction.

21 . (canceled)

22 . The medical device of claim 1 wherein the plunger has a rearwardly facing thumb cap that is disposed inside or adjacent to the opening in the rear of the barrel when the plunger is fully depressed inside the barrel.

23 . The medical device of claim 1 wherein a thumb cap disposed at the rear of the plunger is lodged inside a substantially cylindrical collar at the rear of the barrel so as to make the thumb cap difficult to grasp.

24 . The medical device of claim 1 wherein said device is a syringe.

25 . (canceled)

26 . (canceled)

27 . The medical device of claim 1 wherein the plunger is configured to apply a forwardly directed force to the retainer ring through the plunger seal as the plunger is moved forwardly inside the barrel to a point where the plunger seal contacts the retainer ring.

28 . (canceled)

29 . (canceled)

30 . The medical device of claim 3 wherein the blunt surface is stepped longitudinally.

31 . (canceled)

32 . The medical device of claim 1 wherein the plunger seal and retainer ring are made from different elastomeric materials.

33 . A medical device having a barrel, a retractable needle, a needle retraction assembly, and a plunger that slidably engages the barrel, wherein:
the needle retraction assembly is biased to project the needle rearwardly relative to the barrel during retraction of the needle and is held in place relative to the barrel prior to retraction of the needle at least in part by a retainer member that contacts and frictionally engages the barrel; and the plunger comprises an interior retraction cavity, an elastomeric plunger seal disposed on the plunger, at least part of which is rearwardly moveable on the plunger, the plunger seal further comprising an elastomeric web that spans and seals an opening into the retraction cavity prior to retraction of the needle; wherein an annular body portion of the elastomeric plunger seal is displaced and pushed rearwardly on the plunger by an annular shoulder disposed inside the barrel as the plunger is moved forwardly inside the barrel; and wherein the needle retraction assembly further comprises a rearwardly extending projection that contacts and stretches the elastomeric web as the annular body portion of the elastomeric plunger seal is displaced and moved rearwardly on the plunger as the plunger is moved forwardly inside the barrel.

34 . (canceled)

35 . The medical device of claim 33 wherein the needle retraction assembly comprises a plurality of rearwardly extending projections that contact and puncture the elastomeric web as the plunger is moved forwardly inside the barrel.

36 . The medical device of claim 33 wherein the plunger contacts the retainer member to release the retainer member from frictional engagement with the barrel as the plunger is advanced inside the barrel.

37 . The medical device of claim 36 wherein the plunger seal contacts the retainer member to release the needle retraction assembly from frictional engagement with the barrel as the plunger is advanced inside the barrel.

38 . (canceled)

39 . The medical device of claim 37 wherein a portion of the elastomeric web contacts and displaces the elastomeric retainer member forwardly to release the needle retraction assembly from the barrel as the plunger is advanced inside the barrel.

40 . The medical device of claim 33 wherein at least part of the elastomeric web is stretched and thinned as the annular body is moved rearwardly on the plunger.

Assignees

• Shaw Thomas J
• Retractable Technologies Inc

Inventors

• Shaw Thomas J
• Zhu Ni

Classifications

• A61M5/508

  Means for preventing re-use by disrupting the piston seal, e.g. by puncturing · CPC title

• A61M5/3234 Primary

  Fully automatic needle retraction, i.e. in which triggering of the needle does not require a deliberate action by the user · CPC title

• A61M2005/3239

  triggered by dislodgement of outer part anchoring the needle portion to the inside of the syringe barrel wall, e.g. a ring-shaped portion · CPC title

• A61M5/50 Primary

  having means for preventing re-use, or for indicating if defective, used, tampered with or unsterile {(retractable needles or needle protectors with means for preventing re-use A61M5/321)} · CPC title