Syringe plunger driver

• US 5,545,140 A
• Filed: 07/05/1994
• Issued: 08/13/1996
• Est. Priority Date: 05/23/1991
• Status: Expired due to Term

• Current Assignee: Carefusion 303 Incorporated (Becton, Dickinson & Co)
• Original Assignee: Ivax Corporation (Teva Pharmaceutical Industries, Ltd.)
• Inventors: Conero, Ronald S., O'Leary, Stephen H.
• Primary Examiner(s): MCDERMOTT, CORRINE MARIE
• Application Number:
  US08/270,393
• Time in Patent Office: 770 Days
• Field of Search: 604/65, 604/67, 604/151, 604/154, 604/155, 604/245, 128/DIG. 1, 128/DIG. 12, 128/DIG. 13
• US Class Current: 604/154
• CPC Class Codes: A61M 2205/60 with identification means
• CPC Class Codes: A61M 5/1456 with a replaceable reservoir comprising a piston rod to be moved into the reservoir, e.g. the piston rod is part of the removable reservoir
• CPC Class Codes: A61M 5/1458 Means for capture of the plunger flange
• CPC Class Codes: Y10S 128/01 Motorized syringe

Abstract

A plunger driver system which engages a plurality of different sizes of syringes. A pushing surface includes a detector to determine syringe plunger presence. In the event that the plunger is not present and the pump is operating, a processor provides an alarm and may stop the pump motor. Arms retain the plunger flange in a fixed position in relation to the plunger driver. The arms have anti-siphon flanges to prevent too rapid movement of the plunger into the syringe barrel. A shelf for opposing downward movement of the syringe plunger and a ramp to guide the syringe plunger into position in relation to the plunger driver are included in the plunger driver. A cradle for containing all sizes of syringe barrels yet aligning the syringes with the plunger driver is included with a clamp to hold the syringe barrel in position in the cradle. The detector button includes a bevel at its top edge to facilitate loading the plunger in the driver. The plunger driver arms are biased independently from the screw drive disengagement mechanism. A ramp is also formed with the shelf to assist in guiding the syringe plunger into position during syringe installation.

Claims

1. A plunger driver system for engaging selected plungers of syringes of different sizes, each plunger moveable in a syringe barrel and each plunger having a plunger flange with an inner side facing the syringe barrel and an outer side, the plunger driver system moving the plunger into the syringe barrel in an operation mode, the plunger driver system comprising:

a pushing surface adapted to press against the outer side of the plunger flange to move the plunger into the barrel of the syringe during the operation mode;

a plunger retainer adapted to engage the inner side of the plunger flange and physically retain the flange within a predetermined distance from the pushing surface;

a detector coupled to the pushing surface to detect the presence of the plunger flange within the predetermined distance between the pushing surface and the plunger retainer during the operation mode and to provide a detector signal indicating the presence of the plunger, the detector having a detection range large enough to detect the presence of all of the plunger flanges of the different sizes when located between the pushing surface and the plunger retainer;

a spring coupled to the plunger retainer to bias the plunger retainer into contact with the plunger flange; and

a processor which receives the detector signal and monitors the detector signal during the operation mode and provides an alarm in the event that the detector signal indicates a syringe plunger not present during the operation mode.

2. The system of claim 1 wherein the plunger flange detector comprises:

a button mounted in the pushing surface;

a spring which biases the button outward into contact with the plunger flange; and

a sensor positioned to detect the position of the button and thereby determine the presence of a plunger flange.

3. The system of claim 2 wherein the button comprises a beveled top surface.

4. The plunger driver system of claim 2:

wherein the button comprises a sensing flag moving with the button and movable to a first position in response to a plunger flange being located between the pushing surface and the plunger retainer and movable to a second position when no plunger flange is located between the pushing surface and the plunger retainer;

further comprising a detecting device responsive to the position of the flag to provide the detector signal indicating the position of the flag;

wherein the detecting device is mounted at the second position of the flag and during the operation mode, the processor tests the detecting device for correct operation thereby verifying that the detecting device has not failed.

5. The plunger driver system of claim 4 wherein the detecting device provides an optical beam and is mounted so that when the flag is in the first flag position, the flag does not break the optical beam;

wherein the processor pulses the optical beam when the flag is in the first flag position and provides an alarm if the detecting device does not detect the pulsed optical beam.

6. The system of claim 1 wherein:

the pushing surface comprises a shelf for receiving the plunger flanges; and

the plunger retainer applies a downward force to plunger flanges in the direction of the shelf.

7. The system of claim 1 further comprising a ramp disposed adjacent the bottom of the pushing surface which engages the plunger to guide it into a desired position on the pushing surface.

8. The system of claim 1 wherein:

the pushing surface comprises a shelf for receiving the plunger flanges;

the plunger retainer applies a downward force to plunger flanges in the direction of the shelf; and

further comprising a ramp disposed adjacent the bottom of the pushing surface which engages the plunger to guide it into a desired position on the pushing surface.

9. The plunger driver system of claim 1 further for use with a lead screw driving mechanism which comprises a lead screw, a driver device coupled to the lead screw for movement along the lead screw in response to rotary motion of the lead screw, and a bias mechanism for biasing the driver device into contact with the lead screw, wherein the plunger driver system is connected to the lead screw driving mechanism wherein:

the plunger retainer bias spring is independent from the screw drive bias mechanism.

10. The system of claim 9 further comprising an activating lever which is connected to oppose the bias mechanism of the screw drive mechanism and the lever is also connected to the plunger retainer to disengage the plunger retainer from the plunger flange.

11. The plunger driver system of claim 1 wherein the processor controls the pushing surface to stop pressing against the outer side of the plunger flange upon the processor providing an alarm.

12. The plunger driver system of claim 1 wherein the detector comprises:

a contact device mounted to the pushing surface for movement therewith, said contact device movable to a first contact position in contact with a plunger flange in response to said plunger flange being located between the pushing surface and the plunger retainer and movable to a second noncontact position when no plunger flange is located between the pushing surface and the plunger retainer;

a flag mounted to the contact device and moving therewith, the flag movable to a first flag position in response to the contact device being located in the first contact position and a second flag position in response to the contact device being located in the second noncontact position; and

wherein the detector comprises a detecting device responsive to the position of the flag to provide the detector signal that indicates the position of the flag; and

wherein the detecting device is mounted at the second flag position of the flag and during the operation mode, the processor tests the detecting device for correct operation thereby verifying that the detecting device has not failed.

13. The plunger driver system of claim 12 wherein the detecting device provides an optical beam and is mounted so that when the flag is in the first flag position, the flag does not break the optical beam;

wherein the processor pulses the optical beam when the flag is in the first flag position and provides an alarm if the detecting device does not detect the pulsed optical beam.

14. A plunger driver system for engaging plungers of different sizes, each plunger having a plunger flange, the plunger driver system comprising:

a pushing Surface adapted to press against the plunger flange to move it in a first direction;

a plunger retainer adapted to engage the plunger flange applying lateral force thereto and retaining the flange within a predetermined distance from the pushing surface, the retainer also adjusting itself to the size of the flange, wherein the plunger retainer comprises a pair of pivoted arms biased toward each other and engaging the plunger flange and each arm has an anti-siphon flange for engaging the plunger flange to restrain the flange from movement in the first direction;

a detector coupled with the pushing surface to detect the presence of the plunger flange within the predetermined distance and to provide a detector signal indicating the presence of the plunger, the detector having a detection range large enough to detect the presence of all of the plunger flanges of the different sizes;

a spring coupled to the plunger retainer to bias the plunger retainer into contact with the plunger flange; and

a processor which receives the detector signal and provides an alarm in the event that the detector signal indicates a syringe plunger not present.

15. The system of claim 14 wherein the arms are curved in shape, the curve selected so that the arms will apply lateral force to all of the plunger flanges of the selected plungers.

16. A plunger driver system for engaging plungers of different sizes, each plunger having a plunger flange wherein each of the selected plungers forms a part of a syringe, each syringe having a barrel into and out of which the plunger moves, each plunger flange having an inner side facing the syringe barrel and an outer side, the plunger driver system moving the syringe plunger into the syringe barrel in an operation mode, the plunger driver system comprising:

a pushing surface adapted to press against the outer side of the plunger flange to move the plunger into the barrel of the syringe during the operation mode;

a plunger retainer adapted to engage the inner side of the plunger flange applying lateral force thereto and physically retain the flange within a predetermined distance from the pushing surface, the retainer also adjusting itself to the size of the flange;

a detector coupled with the pushing surface to detect the presence of the plunger flange within the predetermined distance between the pushing surface and the plunger retainer during the operation mode and to provide a detector signal indicating the presence of the plunger, the detector having a detection range large enough to detect the presence of all of the plunger flanges of the different sizes when located between the pushing surface and the plunger retainer;

a spring coupled to the plunger retainer to bias the plunger retainer into contact with the plunger flange;

a processor which receives the detector signal and continuously monitors the detector signal during the operation mode and provides an alarm in the event that the detector signal indicates a syringe plunger not present during the operation mode;

a cradle fixed in position and disposed to engage the barrels of each of the syringes, the cradle having a first surface and a barrel retainer, the first surface and the retainer being disposed to engage the syringe barrel between them; and

the shape of the first surface and the shape of the retainer being selected to engage all syringes such that the longitudinal centerlines of all syringe plungers intersect the pushing surface along a common centerline.

17. The system of claim 16 wherein the first surface and the barrel retainer form a V-shape between them having an included angle of approximately 96 degrees.

18. The system of claim 16 further comprising a barrel clamp mounted above the cradle and biased toward the cradle to press against the barrel of syringe and hold the syringe in a fixed position in the cradle, the mounting position of the barrel clamp selected to provide downward force to all of the selected syringes.

19. The plunger driver system of claim 16 wherein the plunger retainer comprises at least one pivotally mounted arm that includes an anti-siphoning flange for engaging the inner surface of the plunger flange of the mounted syringe to retain the plunger within the predetermined distance of the pushing surface, the arm pivoting in one direction into engagement with the plunger flange and pivoting in another direction away from the flange into a disengaged position.

20. The plunger driver system of claim 19 wherein the plunger retainer comprises a second pivotally mounted arm for engaging the plunger flange of the mounted syringe, the arm pivoting in one direction into engagement with the plunger flange and pivoting in another direction away from the flange into a disengaged position.

21. The plunger driver system of claim 16 wherein the processor controls the pushing surface to stop pressing against the outer side of the plunger flange upon the processor providing an alarm.

22. The plunger driver system of claim 16 wherein the detector comprises:

a contact device mounted to the pushing surface for movement therewith, said contact device movable to a first contact position in contact with a plunger flange in response to said plunger flange being located between the pushing surface and the plunger retainer and movable to a second noncontact position when no plunger flange is located between the pushing surface and the plunger retainer;

a flag mounted to the contact device and moving therewith, the flag movable to a first flag position in response to the contact device being located in the first contact position and a second flag position in response to the contact device being located in the second noncontact position; and

wherein the detector comprises a detecting device responsive to the position of the flag to provide the detector signal that indicates the position of the flag; and

wherein the detecting device is mounted at the second flag position of the flag and during the operation mode, the processor tests the detecting device for correct operation thereby verifying that the detecting device has not failed.

23. The plunger driver system of claim 22 wherein the detecting device provides an optical beam and is mounted so that when the flag is in the first flag position, the flag does not break the optical beam;

wherein the processor pulses the optical beam when the flag is in the first flag position and provides an alarm if the detecting device does not detect the pulsed optical beam.

24. A plunger driver system for engaging plungers of different sizes, each plunger having a plunger flange, said plunger driver being connected to a lead screw driving mechanism which comprises a lead screw, a driver device coupled to the lead screw for movement along the lead screw in response to rotary motion of the lead screw and a bias mechanism for biasing the driver device into contact with the lead screw, comprising:

a pushing surface which is adapted to press against the plunger flange to move it in a first direction;

a plunger retainer adapted to engage the plunger flange applying lateral force thereto and retaining the flange within a predetermined distance from the pushing surface, the retainer also adjusting itself to the size of the flange wherein;

the plunger retainer comprises a pair of pivoted arms biased toward each other and engaging the plunger flange, the arms are curved in shape, the curve selected so that the arms will apply lateral force to all of the plunger flanges of the selected plungers; and

each arm has an anti-siphon flange for engaging the plunger flange to restrain the flange from movement in the first direction;

a detector coupled to the pushing surface to detect the presence of the plunger flange within the predetermined distance and to provide a detector signal indicating the presence of the plunger, the detector having a range of detection large enough to detect the presence of all of the plunger flanges of the plungers of different sizes;

a spring coupled to the plunger retainer to bias the plunger retainer into contact with the plunger flange and which is independent from the screw drive bias mechanism;

an activating lever which is connected to the lead screw drive mechanism to oppose the bias mechanism of the screw drive mechanism and the lever is also connected to the plunger retainer to disengage the plunger retainer from the plunger flange; and

a processor which receives the detector signal and provides an alarm in the event that the detector signal indicates a syringe plunger not present.

25. The system of claim 24 wherein the detector comprises:

a button mounted in the pushing surface;

a spring which biases the button outward into contact with the plunger flange;

a flag mounted to the button which moves with the button; and

an optical sensor positioned to detect the flag to determine the position of the button and thereby determine the presence of a plunger flange.