Syringes, syringe plungers and injector systems

• US 5,947,935 A
• Filed: 11/25/1997
• Issued: 09/07/1999
• Est. Priority Date: 11/12/1996
• Status: Expired due to Term

• Current Assignee: Bayer Healthcare LLC (Bayer AG)
• Original Assignee: Medrad Incorporated (Bayer AG)
• Inventors: Rhinehart, Edward J., Reilly, David M., Hitchins, Mark W., McCoppin, Anthony S.
• Primary Examiner(s): YASKO JR, JOHN D
• Application Number:
  US08/978,226
• Time in Patent Office: 651 Days
• Field of Search: 604/218, 604/131, 604/152, 604/220, 604/221, 604/232, 604/151
• US Class Current: 604/218
• CPC Class Codes: A61M 5/14546 Front-loading type injectors
• CPC Class Codes: A61M 5/14566 with a replaceable reservoir for receiving a piston rod of the pump
• CPC Class Codes: A61M 5/31515 Connection of piston with piston rod

Abstract

The present invention provides a connection mechanism adapted to make a releasable connection between a syringe plunger and a drive member of an injector. The drive member is preferably movable in a generally reciprocal linear manner to control movement of the plunger within the syringe. The connection mechanism comprises at least one capture member attached to the plunger. The capture member forms a releasable connection with the drive member upon contact of the drive member during linear forward motion of the drive member when the capture member is rotated relative to the drive member to an engagement position. The capture member is further adapted to disconnect from the drive member upon rotation of the capture member relative to the drive member to a disengagement position.

Claims

1. A plunger adapted to be releasably connected to an injector drive member by means of a releasable connection mechanism, the releasable connection mechanism comprising at least one capture member associated with one of the plunger and the drive member, the at least one capture member adapted to form a releasable engagement with the other of the drive member and the plunger upon contact of the drive member with the plunger during linear forward motion of the drive member relative to the plunger when the at least one capture member is in an engagement position, the at least one capture member further being adapted to release one of the drive member and the plunger upon relative rotation of the at least one capture member to a disengagement position.

2. The plunger of claim 1 wherein the at least one capture member comprises two capture members.

3. The plunger of claim 1 wherein the at least one capture member is associated with the plunger.

4. The plunger of claim 1 wherein the at least one capture member is fabricated from a relatively flexible material and deflects radially outwardly upon contact with the other of the drive member and the plunger.

5. The plunger of claim 4, further comprising at least one radially outward extending flange associated with the other of the drive member and the plunger, the at least one flange cooperable with the at least one capture member to releasably connect the drive member and the plunger.

6. The plunger of claim 1 wherein the at least one capture member is fabricated from a relatively rigid material and deflects radially inwardly upon contact with the other of the drive member and the plunger.

7. The plunger of claim 3 wherein the at least one capture member is adapted to resist disengagement from the drive member when the drive member is moved rearward and the drive member and the at least one capture member are connected in the engagement position.

8. The plunger of claim 3 wherein the at least one capture member comprises rotatable retention members, the retention members comprising a retention shoulder that rotates to retain the drive member in contact with the retention members when the drive member and the at least one capture member are in the engagement position.

9. The plunger of claim 1, further comprising a mechanism that substantially prevents reconnection of the drive member to the plunger after an initial connection therebetween has been disconnected.

10. A syringe comprising:

a main body portion;

a plunger slidably disposed within the main body portion, the plunger adapted to be releasably connected to an injector drive member; and

a releasable connection mechanism adapted to make a releasable connection between the plunger and the injector drive member, the releasable connection mechanism comprising at least one capture member attached to one of the plunger and the drive member, the at least one capture member adapted to form a releasable engagement with the other of the drive member and the plunger upon contact of the drive member with the plunger during linear forward motion of the drive member relative to the plunger when the at least one capture member is in an engagement position, the at least one capture member further being adapted to resist disengagement from one of the drive member and the plunger when the drive member is moved rearward and the at least one capture member is in an engagement position and to release one of the drive member and the plunger upon relative rotation of the at least one capture member to a disengagement position.

11. The syringe of claim 10 wherein the at least one capture member comprises at least two capture members.

17. The syringe of claim 10 wherein the at least one capture member is associated with the plunger.

18. The syringe of claim 10 wherein the at least one capture member deflects radially outwardly upon contact with the other of the drive member and the plunger.

19. The syringe of claim 18, further comprising at least one radially outward extending flange associated with the other of the drive member and the plunger, the at least one flange cooperable with the at least one capture member to releasably connect the drive member and the plunger.

20. The syringe of claim 10 wherein the at least one capture member deflects radially inwardly upon contact with the other of the drive member and the plunger.

21. The syringe of claim 17 wherein the at least one capture member comprises rotatable retention members, the retention members comprising a retention shoulder that rotates to retain the drive member in contact with the retention members when the drive member and the at least one capture member are in the engagement position.

22. The syringe of claim 10, further comprising a mechanism that substantially prevents reconnection of the drive member to the plunger after an initial connection therebetween has been disconnected.

12. An injector system for injecting a fluid medium, the injector system comprising:

an injector comprising a drive member, the drive member being movable in a generally reciprocal linear manner;

a syringe comprising a main body portion and a plunger slidably disposed within the main body portion; and

a releasable connection mechanism operable to releasably connect the drive member and the plunger, the connection mechanism comprising at least two capture members attached to the plunger, the capture members adapted to form a releasable connection upon contact of the drive member with the capture members during linear forward motion of the drive member relative to the plunger when the capture members are in an engagement position relative to the drive member, the capture members further being adapted to release the drive member upon relative rotation of the capture members to a disengagement position relative to the drive member.

23. The injector system of claim 12 wherein the at least one capture member deflects radially outwardly upon contact with the drive member.

24. The injector system of claim 23, further comprising at least one radially outward extending flange associated with the drive member, the at least one flange cooperable with the at least one capture member to releasably connect the drive member and the plunger.

25. The injector system of claim 12 wherein the at least one capture member deflects radially inwardly upon contact with the drive member.

26. The injector system of claim 12 wherein the at least one capture member is adapted to resist disengagement from the drive member when the drive member is moved rearward and the drive member and the at least one capture member are connected in the engagement position.

27. The injector system of claim 12 wherein the at least one capture member comprises rotatable retention members, the retention members comprising a retention shoulder that rotates to retain the drive member in contact with the retention members when the drive member and the at least one capture member are in the engagement position.

28. The injector system of claim 12, further comprising a mechanism that substantially prevents reconnection of the drive member to the plunger after an initial connection therebetween has been disconnected.

13. A syringe for use with an injector having a drive member, the syringe comprising:

a body portion; and

a plunger slidably disposed within the body portion, the plunger comprising a releasable connection mechanism adapted to make a releasable connection with a connection member on the injector drive member, the releasable connection mechanism comprising at least one capture member attached to the plunger, the at least one capture member adapted to form a releasable engagement with the connection member upon contact of the drive member with the at least one capture member during forward motion of the drive member relative to the plunger when the at least one capture member is in an engagement position relative to the drive member, the at least one capture member further being adapted to resist disengagement from the connection member of the drive member when the drive member is moved rearward and the drive member and the at least one capture member are in the engagement position and to release the drive member upon rotation of the at least one capture member to a disengagement position relative to the drive member.

29. The syringe of claim 13 wherein the at least one capture member comprises two capture members.

30. The syringe of claim 13 wherein the at least one capture member deflects radially outwardly upon contact with the drive member.

31. The syringe of claim 30, further comprising at least one radially outward extending flange associated with the drive member, the at least one flange cooperable with the at least one capture member to releasably connect the drive member and the plunger.

32. The syringe of claim 13 wherein the at least one capture member deflects radially inwardly upon contact with the drive member.

33. The syringe of claim 13 wherein the at least one capture member comprises rotatable retention members, the retention members comprising a retention shoulder that rotates to retain the drive member in contact with the retention members when the drive member and the at least one capture member are in the engagement position.

34. The syringe of claim 13, further comprising a mechanism that substantially prevents reconnection of the drive member to the plunger after an initial connection therebetween has been disconnected.

14. A syringe plunger adapted to be releasably connected to a drive member of an injector by means of a releasable connection mechanism, the releasable connection mechanism comprising at least one capture member associated with one of the plunger and the drive member, the at least one capture member adapted to form a releasable connection with the other of the drive member and the plunger upon contact of the drive member with the plunger during forward motion of the drive member relative to the plunger when the at least one capture member is in an engagement position, the at least one capture member further being adapted to resist disengagement from the other of the drive member and the plunger when the drive member is moved rearward and the at least one capture member is in the engagement position and to release one of the drive member and the plunger upon rotation of the at least one capture member to a disengagement position.

35. The syringe plunger of claim 14 wherein the at least one capture member is associated with the plunger.

36. The syringe plunger of claim 14 wherein the at least one capture member comprises two capture members.

37. The syringe plunger of claim 14 wherein the at least one capture member deflects radially outwardly upon contact with the other of the drive member and the plunger.

38. The syringe plunger of claim 37, further comprising at least one radially outward extending flange associated with the other of the drive member and the plunger, the at least one flange cooperable with the at least one capture member to releasably connect the drive member and the plunger.

39. The syringe plunger of claim 14 wherein the at least one capture member deflects radially inwardly upon contact with the other of the drive member and the plunger.

40. The syringe plunger of claim 35 wherein the at least one capture member comprises rotatable retention members, the retention members comprising a retention shoulder that rotates to retain the drive member in contact with the retention members when the drive member and the at least one capture member are in the engagement position.

41. The syringe plunger of claim 14, further comprising a mechanism that substantially prevents reconnection of the drive member to the plunger after an initial connection therebetween has been disconnected.

15. A plunger adapted to be releasably connected to an injector drive member by means of a releasable connection mechanism, the releasable connection mechanism comprising at least one capture member associated with one of the plunger and the drive member, the at least one capture member being fabricated from a relatively flexible material and adapted to deflect radially outwardly to cooperably form a releasable engagement with at least one radially outward extending flange associated with the other of the drive member and the plunger upon contact of the drive member with the plunger during linear forward motion of the drive member relative to the plunger when the at least one capture member is in an engagement position.

16. A plunger adapted to be releasably connected to an injector drive member by means of a releasable connection mechanism, the releasable connection mechanism comprising at least one capture member associated with the plunger, the at least one capture member adapted to form a releasable engagement with the drive member upon contact of the drive member with the plunger during linear forward motion of the drive member relative to the plunger when the at least one capture member is in an engagement position, the at least one capture member further being adapted to resist disengagement from the drive member when the drive member is moved rearward and the drive member and the at least one capture member are connected in the engagement position.