Syringe plunger locking mechanism

• US 6,752,789 B2
• Filed: 07/20/2001
• Issued: 06/22/2004
• Est. Priority Date: 07/20/2000
• Status: Expired due to Term

• Current Assignee: ACIST Medical Systems Incorporated (Bracco SPA)
• Original Assignee: ACIST Medical Systems Incorporated (Bracco SPA)
• Inventors: McPeak, Thomas, Gerold, Jason, Duchon, Douglas
• Primary Examiner(s): MENDEZ, MANUEL A
• Application Number:
  US09/909,734
• Publication Number:
  US 20020022807A1
• Time in Patent Office: 1,068 Days
• Field of Search: 604/228, 604/218, 604/187, 604/221, 604/197, 604/222, 604/214, 604/154, 604/155, 128/DIG.1, 128/DIG.12, 128/DIG.13
• 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 an injector, the actuating shaft adapted for reciprocal motion to control movement of the plunger, the releasable connection mechanism including;

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 release member of the injector, wherein said release member is a plate defining an aperture through which the actuating shaft passes; and

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.

2. 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 an 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, wherein the capture member is adapted to release the actuating shaft upon engagement with a release member of the injector, and wherein said release member is a plate defining an aperture through which the actuating shaft passes;

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

3. 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 capable of coupling to the syringe plunger and movable through the syringe body to control movement of the syringe plunger;

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 an engagement position;

a release actuator disposed proximal to the syringe body, wherein said 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 contacted by the actuating shaft to form a releasable engagement with the actuating shaft when the actuating shaft and the capture member are in the engagement position, and to flex radially outwardly when contacting the distal surface of the plate such that the syringe plunger disengages with the actuating shaft; and

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. The syringe of claim 3, 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.

5. 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 a capture member projecting outwardly therefrom in a proximal direction, said capture member including a finger extending radially outwardly therefrom;

providing a release member comprising a plate located proximal to the syringe body and including an aperture;

driving the actuating shaft through the aperture 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 through the aperture such that the finger abuts against a surface of the plate and causes the capture member to flex radially outwardly to disengage the syringe plunger from the actuating shaft.

6. 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 an injector, the actuating shaft adapted for reciprocal motion to control movement of the plunger, the releasable connection mechanism including;

a capture member projecting from the plunger, the capture member adapted to flex radially 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 release member of the injector; and

a finger extending radially from the capture member, the finger adapted to disengage the capture member from the actuating shaft.

7. 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 an actuating shaft, the connection mechanism including a capture member projecting from the syringe plunger;

wherein the capture member is adapted to flex radially 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, wherein the capture member is adapted to release the actuating shaft upon engagement with a release member of the injector; and

said syringe plunger further comprising a finger extending radially from said capture member, the finger adapted to disengage the capture member from the actuating shaft.

8. 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 an injector, the actuating shaft adapted for reciprocal motion to control movement of the plunger;

wherein the releasable connection mechanism includes a capture member projecting from the plunger, the capture member adapted to flex 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;

wherein the capture member is further adapted to release the actuating shaft upon engagement with a release member of the injector; and

wherein the capture member is further adapted to be permanently deformed when released from the actuating shaft by engagement with the release member.

9. The plunger of claim 8, wherein the capture member, after being permanently deformed, cannot engage the actuating shaft.

10. The syringe of claim 9, wherein the release member is a plate defining an aperture, wherein the actuating shaft passes through the aperture.

11. The syringe of claim 10, further comprising a finger extending radially outwardly from the capture member, the finger adapted to abut against a surface of the plate to disengage the capture member from the actuating shaft.

12. The syringe of claim 9, wherein the capture member is permanently deformed by breaking away from the plunger upon release from the actuating shaft.

13. The syringe of claim 9, wherein a portion of the capture member breaks away from the plunger upon release from the actuating shaft.

14. The syringe of claim 9, wherein the capture member extends proximally from the plunger and is adapted to flex radially outwardly when contacted by the actuating shaft.

15. A plunger for use in a syringe having a cylindrical syringe body containing the plunger, the plunger comprising:

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

wherein the releasable connection mechanism includes a capture member projecting from the plunger, the capture member adapted to flex 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; and

wherein the force required for engagement of the capture member to the actuating shaft is less than the initial friction force of the plunger in the syringe body such that the plunger remains essentially stationary relative to the syringe body during engagement.

16. The syringe of claim 15, wherein the capture member extends proximally from the plunger and is adapted to flex radially outwardly when contacted by the actuating shaft.

17. The syringe of claim 15, wherein the release member is a plate defining an aperture, wherein the actuating shaft passes through the aperture.

18. The syringe of claim 17, 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.

19. The syringe of claim 15, wherein the engagement force is less than approximately 10 lbf (44.5 N).

20. The syringe of claim 15 further comprising inlet and outlet ports, wherein said ports are adapted to be occluded to aid engagement of the plunger capture member with the actuating shaft.