Syringe plunger locking mechanism

• US 20020022807A1
• Filed: 07/20/2001
• Published: 02/21/2002
• Est. Priority Date: 07/20/2000
• Status: Active Grant

• Current Assignee: ACIST Medical Systems Incorporated (Bracco SPA)
• Original Assignee: ACIST Medical Systems Incorporated (Bracco SPA)
• Inventors: McPeak, Thomas, Duchon, Douglas, Gerold, Jason
• Granted Patent: US 6,752,789 B2
• Time in Patent Office: Days
• US Class Current: 604/228
• CPC Class Codes: A61B 6/548 Remote control of the apparatus or devices
• CPC Class Codes: A61M 2005/14208 with a programmable infusion control system, characterised by the infusion program
• CPC Class Codes: A61M 5/14216 Reciprocating piston type
• CPC Class Codes: A61M 5/14546 Front-loading type injectors
• CPC Class Codes: A61M 5/31511 Piston or piston-rod constructions, e.g. connection of piston with piston-rod A61M5/5066 takes precedence
• CPC Class Codes: A61M 5/31515 Connection of piston with piston rod
• CPC Class Codes: A61M 5/365 Air detectors A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626

Abstract

A injection system having a syringe body which defines a pumping chamber. A syringe plunger is located in the pumping chamber and is adapted for reciprocal motion within the pumping chamber. The syringe plunger includes a capture member projecting outwardly in a proximal direction. An actuating shaft is coupled to the syringe plunger and is movable through the syringe body to control movement of the syringe plunger. The capture member is adapted to flex radially outwardly when contacted by the actuating shaft to form a releasable engagement with the actuating shaft when the actuating shaft and the capture member are in an engagement position. A release actuator is disposed proximal to the syringe body, and the capture member releases the actuating shaft upon engagement with the release actuator.

Claims

1. A plunger for use in a syringe, the plunger comprising:

a releasable connection mechanism adapted to make a releasable connection with an actuating shaft of the syringe, the actuating shaft adapted for reciprocal motion to control movement of the plunger;

wherein the releasable connection mechanism includes a capture member projecting proximally from the plunger, the capture member adapted to flex radially outwardly when contacted by the actuating shaft to form a releasable engagement with the actuating shaft when the actuating shaft and the capture member are in an engagement position relative to each other, the capture member further adapted to release the actuating shaft upon engagement with a releasing member of the syringe.

2. The plunger of claim 1, wherein the release member is a plate defining an aperture, wherein the actuating shaft passes through the aperture.

3. The plunger of claim 2, further comprising a finger extending radially outwardly from the capture member, the finger adapted to abut against an inner surface of the plate to disengage the capture member from the actuating shaft.

4. A syringe for use with an injector having an actuating shaft, the syringe comprising:

a syringe plunger having a releasable connection mechanism adapted to releasably connect with the actuating shaft, the connection mechanism including a capture member projecting proximally from the syringe plunger;

wherein the capture member is adapted to flex radially outwardly when contacted by the actuating shaft to form a releasable engagement with the actuating shaft when the actuating shaft and the capture member are in an engagement position; and

wherein the capture member is adapted to release the actuating shaft upon engagement with a release member of the syringe.

5. The syringe of claim 4, wherein the release member is a plate defining an aperture, wherein the actuating shaft passes through the aperture.

6. The syringe of claim 5, further comprising a finger extending radially outwardly from the capture member, the finger adapted to abut against an inner surface of the plate to disengage the capture member from the actuating shaft.

7. An injection system comprising:

a syringe body having a distal portion and a proximal portion, the syringe body defining a pumping chamber;

a syringe plunger located in the pumping chamber and adapted for reciprocal motion, the syringe plunger having a capture member projecting outwardly in a proximal direction;

an actuating shaft coupled to the syringe plunger and movable through the syringe body to control movement of the syringe plunger;

wherein the capture member is adapted to flex radially outwardly when contacted by the actuating shaft to form a releasable engagement with the actuating shaft when the actuating shaft and the capture member are in an engagement position; and

a release actuator disposed proximal to the syringe body;

wherein the capture member is adapted to release the actuating shaft upon engagement with the release actuator.

8. The injection system of claim 7, wherein the release actuator is a plate defining an aperture for allowing manipulation of the syringe plunger, wherein the capture member is adapted to flex radially outwardly when contacting a distal surface of the plate such that the syringe plunger disengages with the actuating shaft.

9. The syringe of claim 8, further comprising:

a groove circumscribing the actuator shaft;

a latch disposed on an inner surface of the capture member, the latch secured to the groove when the actuating shaft and the capture member are in the engagement position;

a finger extending radially outwardly from the capture member, the finger adapted to abut against an inner surface of the plate to disengage the capture member from the actuating shaft.

10. The syringe of claim 9, wherein the syringe plunger is cylindrically shaped and has a first outer diameter, wherein the actuating shaft is cylindrically shaped and has a second outer diameter, wherein the first outer diameter is greater than the second outer diameter, wherein an outer end of the finger extends substantially beyond the second outer diameter and extends substantially within the first outer diameter such that actuating shaft is adapted to pass through the aperture of the plate and the finger is restricted from passing through the aperture of the plate.

11. A method of connecting and disconnecting a syringe plunger from an actuating shaft of an injection system, comprising:

providing a syringe body having a distal portion and a proximal portion, the syringe body defining a pumping chamber;

providing a syringe plunger within the pumping chamber, the syringe plunger having capture member projecting outwardly therefrom in a proximal direction;

driving the actuating shaft towards the syringe plunger such that a distal portion of the actuating shaft forces the capture member radially outwardly to form a releasable engagement with the syringe plunger; and

retracting the actuating shaft such that the capture member abuts against a release member and forces the capture member radially outwardly to disengage the syringe plunger from the actuating shaft.

12. The method of claim 11, further comprising passing the actuating shaft through an aperture of the release member, the release member being a plate located proximal to the syringe body.

13. The method of claim 11, wherein said providing a syringe plunger further includes providing a finger which extends radially outwardly from the capture member such that the finger abuts against an inner surface of the plate and causes the capture member to flex radially outwardly.

15. The injection system of claim 14, further comprising:

a groove circumscribing a surface of the syringe plunger;

wherein the release actuator is a plate defining an aperture for allowing manipulation of the syringe plunger;

wherein the distal portion of the pivot member includes a latch projecting outwardly from an inner surface thereof, the latch secured to the groove when the actuating shaft and the pivot member are in the engagement position; and

wherein the proximal portion of the pivot member includes a ramped lug projecting outwardly from an outer surface thereof, the ramped lug slidingly engaging with a sidewall of the aperture to drive the proximal end of the pivot member radially inwardly and to drive the distal end of the pivot member radially outwardly such that actuating shaft disengages with the syringe plunger.

16. The injection system of claim 15, wherein the pivot member includes a first pivot member opposing a second pivot member, the injection system further comprising:

a bias member coupled to the first pivot member and the second pivot member, the bias member forcing the proximal ends of the first pivot member and the second pivot member in a radially outward direction, and the bias member forcing the distal ends of the first pivot member and the member in a radially inward direction.

17. The injection system of claim 16, wherein the bias member is a spring.

19. The method of claim 18, further comprising:

providing a groove circumscribing a surface of the syringe plunger;

wherein the release actuator is a plate defining an aperture for allowing manipulation of the syringe plunger;

wherein the distal portion of the pivot member includes a latch projecting outwardly from an inner surface thereof, the latch secured to the groove when the actuating shaft and the pivot member are in the engagement position; and

wherein the proximal portion of the pivot member includes a ramped lug projecting outwardly from an outer surface thereof, the ramped lug slidingly engaging with a sidewall of the aperture to drive the proximal end of the pivot member radially inwardly and to drive the distal end of the pivot member radially outwardly such that actuating shaft disengages with the syringe plunger.

20. The method of claim 19, wherein the pivot member includes a first pivot member opposing a second pivot member, the injection system further comprising:

coupling a bias member to the first pivot member and the second pivot member, the bias member forcing the proximal ends of the first pivot member and the second pivot member in a radially outward direction, and the bias member forcing the distal ends of the first pivot member and the second member in a radially inward direction.

14. An injection system comprising:

a syringe body having a distal portion and a proximal portion, the syringe body defining a pumping chamber;

a syringe plunger located in the pumping chamber and adapted for reciprocal motion within the pumping chamber;

an actuating shaft coupled to the syringe plunger and movable through the syringe body to control movement of the plunger, the actuating shaft having a pivot member disposed at a distal portion thereof;

a release actuator disposed proximal to the syringe body;

wherein a distal portion of the pivot member is adapted to project radially outwardly when contacted by the syringe plunger to form a releasable engagement with the syringe plunger when the actuating shaft and the pivot member are in an engagement position; and

wherein the distal portion of the pivot member is adapted to release the actuating shaft upon engagement of a proximal portion of the pivot member with the release actuator.

18. A method of connecting and disconnecting a syringe plunger from an actuating shaft of an injection system, comprising:

providing a syringe body having a distal portion and a proximal portion, the syringe body defining a pumping chamber;

providing an actuating shaft capable of coupling with the syringe plunger, the actuating shaft having a pivot member disposed at a distal portion thereof; and

providing a release actuator proximal to the pumping chamber;

wherein a distal portion of the pivot member projects radially outwardly when contacted by the syringe plunger to form a releasable engagement with the syringe plunger when the actuating shaft and the pivot member are in an engagement position; and

wherein the distal portion of the pivot member releases the actuating shaft upon engagement of a proximal portion of the pivot member with the release actuator.

21. A plunger for use in a syringe having an actuating shaft adapted for reciprocating motion to control movement of the plunger, the plunger comprising:

a U-shaped tongue disposed at a proximal portion of the plunger, the U-shaped tongue releasably connected with a circumscribing groove of the actuating shaft;

wherein the plunger is in an engaged position with the actuating shaft when the U-shaped tongue is slidingly fitted onto the circumscribing groove; and

wherein the plunger is in a disengaged position with the actuating shaft when the U-shaped tongue is slidingly withdrawn from the circumscribing groove.

22. An injection system comprising:

a syringe body having a distal portion and a proximal portion, the syringe body defining a pumping chamber;

a syringe plunger located in the pumping chamber and adapted for reciprocal motion between a position proximate to the proximal portion and the distal portion, the syringe plunger having first aperture disposed at a proximal portion thereof; and

an actuating shaft coupled to the plunger and movable through the syringe body to control movement of the plunger, the actuating shaft having a pivot member disposed at a distal portion thereof;

a release actuator disposed at a proximal portion of the injection system;

wherein a distal portion of the pivot member is adapted to project radially inwardly when contacted by a sidewall of the first aperture to form a releasable engagement with the syringe plunger; and

wherein the distal portion of the pivot member is adapted to project radially inwardly to disengage the syringe plunger from the actuating shaft when a proximal portion of the pivot member slidingly contacts the release actuator and moves radially inwardly.

23. The injection system of claim 22, wherein the release actuator is a plate defining a second aperture;

wherein the proximal portion of the pivot member includes a ramped lug projecting outwardly from an outer surface thereof, the latch secured to the sidewall of the first aperture when the actuating shaft and the pivot member are in the engagement position; and

wherein the proximal portion of the pivot member includes a ramped lug projecting outwardly from an outer surface thereof, the ramped lug slidingly engaging with a side wall of the second aperture to drive the proximal end of the pivot member radially inwardly and to drive the distal end of the pivot member radially inwardly such that actuating shaft disengages with the syringe plunger.

24. The injection system of claim 23, wherein the pivot member includes a first pivot member and a second pivot member having a common pivot point, the injection system further comprising:

a bias member coupled to the first pivot member and the second pivot member, the bias member forcing the first pivot member and the second pivot member radially outwardly such that a distal portion of the first pivot member and the second pivot member are forced radially outwardly.

25. The injection system of claim 24, wherein the bias member is a spring.

27. The method of claim 26,

wherein the release actuator is a plate defining a second aperture;

wherein the proximal portion of the pivot member includes a ramped lug projecting outwardly from an outer surface thereof, the latch secured to the sidewall of the first aperture when the actuating shaft and the pivot member are in the engagement position; and

wherein the proximal portion of the pivot member includes a ramped lug projecting outwardly from an outer surface thereof, the ramped lug slidingly engaging with a side wall of the second aperture to drive the proximal end of the pivot member radially inwardly and to drive the distal end of the pivot member radially inwardly such that actuating shaft disengages with the syringe plunger.

28. The method of claim 27, wherein the pivot member includes a first pivot member and a second pivot member having a common pivot point, the injection system further comprising:

a bias member coupled to the first pivot member and the second pivot member, the bias member forcing a proximal portion of the first pivot member and the second pivot member radially outwardly such that a distal portion of the first pivot member and the second pivot member are forced radially outwardly.

29. The method of claim 28, wherein the bias member is a spring.

26. A method of connecting and disconnecting a syringe plunger from an actuating shaft of an injection system, comprising:

providing the syringe plunger with an aperture at a proximal portion thereof;

providing a syringe body having a distal portion and a proximal portion, the syringe body defining a pumping chamber;

providing an actuating shaft capable of coupling with the syringe plunger, the actuating shaft having a pivot member disposed at a distal portion thereof; and

providing a release actuator proximal to the pumping chamber;

wherein a distal portion of the pivot member projects radially inwardly when contacted by the syringe plunger to form a releasable engagement with the syringe plunger when the actuating shaft and the pivot member are in an engagement position; and

wherein the distal portion of the pivot member projects radially inwardly to disengage the syringe plunger from the actuating shaft when a proximal portion of the pivot member slidingly contacts the release actuator and moves radially inwardly.

30. An injection system comprising:

a syringe body having a distal portion and a proximal portion, the syringe body defining a pumping chamber;

a syringe plunger located in the pumping chamber and adapted for reciprocal motion within the pumping chamber;

an actuating shaft coupled to the syringe plunger and movable through the syringe body to control movement of the syringe plunger;

a releasable connection mechanism adapted to make a releasable connection with the actuating shaft and the syringe plunger, the releasable connection comprising;

a ferrous metal member disposed on one of the syringe plunger and the actuating shaft; and

a permanent magnet disposed on the other one of the syringe plunger and the actuating shaft;

wherein the syringe plunger is in an engaged position with the actuating shaft when the permanent magnet is magnetically attached to the ferrous metal member.

31. The syringe plunger of claim 30, wherein the syringe plunger includes a plunger support member and a wiper, wherein the wiper is attached to the plunger support member, wherein the ferrous metal is disposed on one of the plunger support member and the actuating shaft, and wherein a zero insertion force is required to engage the syringe plunger with the actuating shaft.

32. An injection system comprising:

a syringe body having a distal portion and a proximal portion, the syringe body defining a pumping chamber;

a syringe plunger located in the pumping chamber and adapted for reciprocal motion within the pumping chamber;

an actuating shaft coupled to the syringe plunger and movable through the syringe body to control movement of the syringe plunger; and

a releasable connection mechanism adapted to make a releasable connection with the actuating shaft and the syringe plunger, the releasable connection comprising;

an electromagnet disposed on one of the syringe plunger and the actuating shaft; and

a ferrous metal member disposed on the other one of the syringe plunger and the actuating shaft;

wherein the syringe plunger is in an engaged position with the actuating shaft when the electromagnet is magnetically attached to the ferrous metal member.

33. The injection system of claim 32, wherein the syringe plunger includes a plunger support member and a wiper, wherein the wiper is attached to the plunger support member, wherein the ferrous metal member is disposed on one of the plunger support member and the actuating shaft, and wherein a zero insertion force is required to engage the syringe plunger with the actuating shaft.

35. The injection system of claim 34, wherein the syringe plunger includes a plunger support member and a wiper, wherein the wiper is attached to the plunger support member, wherein the electromagnet is disposed on one of the plunger support member and the actuating shaft, and wherein a zero insertion force is required to engage the syringe plunger with the actuating shaft.

37. The injection system of claim 36, wherein the syringe plunger includes a plunger support member and a wiper, wherein the wiper is attached to the plunger support member, wherein the first permanent magnet is disposed on the plunger support member, and wherein a zero insertion force is required to engage the syringe plunger with the actuating shaft.

39. The injection system of claim 38,

wherein the release actuator is a plate defining a second aperture;

wherein a proximal portion of the movable collet members include ramped detachment members projecting outwardly, the detachment members capable of slidably engaging a side wall of the second aperture to drive the proximal end of the movable collet members radially inwardly and to drive the distal end of the movable collet members radially inwardly such that actuating shaft disengages with the syringe plunger.

40. The injection system of claim 39, wherein the movable collet members have a common pivot point, the injection system further comprising:

at least one bias member coupled to the movable first collet member and the movable second collet member, the at least one bias member forcing the movable first collet member and the movable second collet member radially outwardly such that a distal portion of the movable collet members are forced radially outwardly.

41. The injection system of claim 40, wherein the at least one bias member is a spring.

34. An injection system comprising:

a syringe body having a distal portion and a proximal portion, the syringe body defining a pumping chamber;

a syringe plunger located in the pumping chamber and adapted for reciprocal motion within the pumping chamber;

an actuating shaft coupled to the syringe plunger and movable through the syringe body to control movement of the syringe plunger; and

a releasable connection mechanism adapted to make a releasable connection with the actuating shaft and the syringe plunger, the releasable connection comprising;

an electromagnet disposed on one of the syringe plunger and the actuating shaft; and

a permanent magnet disposed on the other one of the syringe plunger and the actuating shaft;

wherein the syringe plunger is in an engaged position with the actuating shaft when the electromagnet is magnetically attached to the permanent magnet.

36. An injection system comprising:

a syringe body having a distal portion and a proximal portion, the syringe body defining a pumping chamber;

a syringe plunger located in the pumping chamber and adapted for reciprocal motion within the pumping chamber;

an actuating shaft coupled to the syringe plunger and movable through the syringe body to control movement of the syringe plunger; and

a releasable connection mechanism adapted to make a releasable connection with the actuating shaft and the syringe plunger, the releasable connection comprising;

a first permanent magnet disposed on the syringe plunger; and

a second permanent magnet disposed on the actuating shaft;

wherein the syringe plunger is in an engaged position with the actuating shaft when the first permanent magnet is magnetically attached to the second permanent magnet.

38. An injection system comprising:

a syringe body having a distal portion and a proximal portion, the syringe body defining a pumping chamber;

a syringe plunger located in the pumping chamber and adapted for reciprocal motion between a position proximate to the proximal portion and the distal portion, the syringe plunger having first aperture disposed at a proximal portion thereof; and

an actuating shaft capable of coupling to the plunger and movable through the syringe body to control movement of the plunger, the actuating shaft having a movable first collet member and a movable second collet member disposed at a distal portion thereof;

a release actuator disposed at a proximal portion of the injection system;

wherein the distal portions of the movable collet members are adapted to project radially inwardly when contacted by a sidewall of the first aperture to form a releasable engagement with the syringe plunger; and

wherein the distal portions of the movable collet members are adapted to project radially inwardly to disengage the syringe plunger from the actuating shaft when a proximal portion of the movable collet members slidably contact the release actuator and move radially inwardly.

42. A method of connecting and disconnecting a syringe plunger from an actuating shaft of an injection system, comprising:

providing the syringe plunger with an aperture at a proximal portion thereof;

providing a syringe body having a distal portion and a proximal portion, the syringe body defining a pumping chamber;

providing an actuating shaft capable of coupling with the syringe plunger, the actuating shaft having a movable first collet member and a movable second collet member disposed at a distal portion thereof; and

providing a release actuator proximal to the pumping chamber;

wherein a distal portion of the movable collet members project radially inwardly when contacted by the syringe plunger to form a releasable engagement with the syringe plunger when the actuating shaft and the movable collet members are in an engagement position; and

wherein the distal portion of the movable collet members project radially inwardly to disengage the syringe plunger from the actuating shaft when a proximal portion of the movable collet members slidably contacts the release actuator and moves radially inwardly.

43. The method of claim 42,

wherein the release actuator is a plate defining a second aperture;

wherein the proximal portion of the movable collet members include a ramped detachment member projecting outwardly, the ramped detachment member capable of slidably engaging with a side wall of the second aperture to drive the proximal end of the movable collet members radially inwardly and to drive the distal end of the movable collet members radially inwardly such that actuating shaft disengages with the syringe plunger.

44. The method of claim 43, wherein the movable collet members include a movable first collet member and a movable second collet member having a common pivot point, the injection system further comprising:

at least one bias member coupled to the movable first collet member and the movable second collet member, the at least one bias member forcing a proximal portion of the movable first collet member and the movable second collet member radially outwardly such that a distal portion of the movable first collet member and the movable second collet member are forced radially outwardly.

45. The method of claim 44, wherein the bias member is a spring.