System and method for syringe plunger engagement with an injector

Patent metadata

Field	Value
Publication number	US-2023285666-A1
Application number	US-202117999592-A
Country	US
Kind code	A1
Filing date	Jun 16, 2021
Priority date	Jun 18, 2020
Publication date	Sep 14, 2023
Grant date	—

Abstract

A plunger for use with a syringe includes a plunger body defining a central longitudinal axis and having a proximal end, a distal end, and a circumferential sidewall connecting the proximal end and the distal end. The plunger further includes at least one retaining member associated with and extending proximally from the plunger body. The at least one retaining member has a first end connected to the plunger body, a second end proximal to the first end and radially and resiliently deflectable relative to the first end, and at least one catch on the second end. A fluid injector system includes a piston having a plunger engagement mechanism configured for interacting with the at least one retaining element of the plunger to releasably engage the plunger for reciprocally driving the plunger within a barrel of the syringe.

First claim

1 . A plunger for use with a syringe, the plunger comprising:
a plunger body defining a central longitudinal axis and having a proximal end, a distal end, and a circumferential sidewall connecting the proximal end and the distal end; and at least one retaining member associated with and extending proximally from the plunger body, the at least one retaining member comprising:
a first end connected to the plunger body;
a second end proximal to the first end and radially and resiliently deflectable relative to the first end; and
at least one catch on the second end,
wherein the at least one retaining member has an outer surface configured to engage a plunger engagement sleeve of a plunger engagement mechanism on a piston of a fluid injector system when the plunger is in a locked state with the piston, wherein the at least one retaining member has an inner surface configured to engage a plunger engagement post of the plunger engagement mechanism when the plunger is in the locked state with the piston, wherein the at least one catch is configured to engage a locking feature on one of the plunger engagement sleeve and the plunger engagement post when the plunger is in the locked state with the piston to prevent axial movement of the plunger relative to the piston, and wherein the at least one catch is configured to radially deflect the second end of the at least one retaining member upon axial movement of the piston relative to the plunger in an unlocked state of the plunger from the piston due to engagement of the at least one catch with the locking feature on one of the plunger engagement sleeve and the plunger engagement post.

2 . The plunger according to claim 1 , wherein the at least one retaining member comprises a plurality of retaining members spaced apart around the central longitudinal axis.

3 . (canceled)

4 . The plunger according to claim 1 , wherein the at least one retaining member extends proximally in a direction parallel with the central longitudinal axis.

5 - 7 . (canceled)

8 . The plunger according to claim 1 , wherein the plunger is configured to engage the plunger engagement mechanism regardless of angular orientation of the plunger relative to the piston of the fluid injector system.

9 . The plunger according to claim 1 , wherein the at least one catch has a first surface at a proximal end of the at least one catch configured for engaging a distal end of the locking feature on one of the plunger engagement sleeve and the plunger engagement post during engagement of the plunger to the piston, and a second surface at a distal end of the at least one catch configured for engaging a proximal end of the locking feature on one of the plunger engagement sleeve and the plunger engagement post during disengagement of the plunger from the piston.

10 . The plunger according to claim 1 , wherein the at least one catch protrudes radially inward from the inner surface of the at least one retaining member in a direction toward the central longitudinal axis.

11 . The plunger according to claim 1 , wherein the at least one catch protrudes radially outward from the outer surface of the at least one retaining member in a direction away from the central longitudinal axis.

12 . The plunger according to claim 1 , wherein the at least one catch defines a locking recess for receiving at least a portion of the plunger engagement mechanism when the plunger is connected to the piston.

13 . The plunger according to claim 1 , wherein the at least one catch protrudes radially inward from the inner surface of the at least one retaining member in a direction toward the central longitudinal axis, and wherein the at least one catch is configured to be received within the locking feature that is shaped as a locking groove protruding radially inward from an outer surface of the plunger engagement post when the plunger is in the locked state with the piston.

14 . The plunger according to claim 1 , wherein the plunger body has conical-shaped portion at the distal end and a cylindrical-shaped portion at the proximal end.

15 . The plunger according to claim 14 , wherein the at least one retaining member protrudes proximally from an inner surface of the conical-shaped portion.

16 . The plunger according to claim 15 , further comprising a plurality of release tabs protruding radially inward from an inner surface of the cylindrical-shaped portion or proximally from the inner surface of the cylindrical-shaped portion, each of the plurality of release tabs configured for interacting with the plunger engagement sleeve to affect release of the plunger from the piston upon rotation of the plunger about the central longitudinal axis.

17 . The plunger according to claim 16 , wherein a proximal end of each of the plurality of release tabs has a pointed guide surface.

18 - 20 . (canceled)

21 . A fluid injector system comprising:
at least one reciprocally operable piston having a piston head; and a plunger engagement mechanism associated with the piston head and configured for engaging a plunger of a syringe connected to the fluid injector system for reciprocally driving the plunger in the syringe due to movement of the at least one piston, the plunger engagement mechanism comprising:
a plunger engagement sleeve having a hollow body;
a plunger engagement post receivable within the hollow body of the plunger engagement sleeve; and
an actuator operatively connected to one of the plunger engagement sleeve and the plunger engagement post, and configured for moving one of the plunger engagement sleeve and the plunger engagement post between an engaged position and a disengaged position,
wherein, in the engaged position, the plunger engagement post is positioned within the hollow body of the plunger engagement sleeve to capture at least one resiliently flexible retaining member associated with the plunger in a receiving space between the plunger engagement collar and the plunger engagement post, and wherein, in the disengaged position, the plunger engagement post is positioned at least partially outside of the hollow body of the plunger engagement sleeve to permit flexible insertion or removal of the at least one resiliently flexible retaining member of the plunger from the receiving space.

22 . The fluid injector system according to claim 21 , wherein the actuator is a rotary electric motor, a linear electric motor, a linear actuator, or a solenoid.

23 . (canceled)

24 . The fluid injector system according to claim 21 , wherein the actuator has an engaged state for moving one of the plunger engagement sleeve and the plunger engagement post to the engaged position and a disengaged state for moving one of the plunger engagement sleeve and the plunger engagement post to the disengaged position.

25 .- 28 . (canceled)

29 . The fluid injector system according to claim 21 , wherein linear movement of the actuator moves one of the plunger engagement sleeve and the plunger engagement post proximally or distally in a linear direction.

30 . The fluid injector system according to claim 21 , wherein the actuator is operatively connected to a controller configured for controlling actuation of the actuator.

31 - 41 . (canceled)

42 . The fluid injector system according to claim 21 , wherein the plunger comprises:
a plunger body defining a central longitudinal axis and having a proximal end, a distal end, and a circumferential sidewall

Assignees

• Bayer Healthcare Llc

Inventors

• Cowan Kevin
• Dedig James
• Taheri Shahab
• Srivastava Abhinav
• Tucker Barry
• Swantner Michael
• Capone Christopher
• Wlodarczyk Jaroslow
• Osan Andrew

Classifications

• A61M2005/14553

  comprising a pressure jacket · CPC title

• A61M5/365

  Air detectors (A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626) · CPC title

• A61M5/31515 Primary

  Connection of piston with piston rod · CPC title

• A61M5/14546 Primary

  Front-loading type injectors · CPC title

• A61M5/007

  for contrast media · CPC title