SYRINGE PUMP ENGAGEMENT DETECTION APPARATUS AND METHODS

• US 20150352294A1
• Filed: 12/27/2013
• Published: 12/10/2015
• Est. Priority Date: 12/28/2012
• Status: Active Grant

• Current Assignee: Gambro Lundia AB (Baxter International Inc.)
• Original Assignee: Gambro Lundia AB (Baxter International Inc.)
• Inventors: O'Mahony, John, Chambers, Joshua
• Granted Patent: US 10,065,003 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61M 2205/14 Detection of the presence or absence of a tube, a connector or a container in an apparatus
• CPC Class Codes: A61M 2205/332 Force measuring means
• CPC Class Codes: A61M 2205/3337 Controlling, regulating pressure or flow by means of a valve by-passing a pump
• CPC Class Codes: A61M 5/1452 pressurised by means of pistons
• CPC Class Codes: A61M 5/1458 Means for capture of the plunger flange
• CPC Class Codes: A61M 5/16854 by monitoring line pressure
• CPC Class Codes: A61M 5/2053 Media being expelled from injector by pressurised fluid or vacuum for infusion A61M5/145, A61M5/155
• CPC Class Codes: A61M 5/31515 Connection of piston with piston rod
• CPC Class Codes: A61M 5/5086 for indicating if defective, used, tampered with or unsterile

Abstract

Syringe pump apparatus and methods for detecting proper or improper engagement of a syringe pump drive system with a syringe in the syringe pump are disclosed. The apparatus and methods can determine proper or improper engagement between a drive system and the plunger of a syringe in a syringe pump by detecting the force required to move a plunger clip in reverse while restricting flow into the syringe. The apparatus and methods may also be used to determine that a syringe in the syringe pump apparatus is properly connected to a delivery line.

Claims

1. A syringe pump apparatus configured to detect engagement between a drive system and a plunger of a syringe in the syringe pump apparatus, the apparatus comprising:

a syringe retainer configured to retain a syringe in a fixed position in the syringe pump apparatus;

a flow control device configured to prevent flow into a syringe retained in the syringe retainer;

a plunger clip configured to capture a plunger of a syringe retained in the syringe retainer;

a drive system configured to move the plunger clip relative to the syringe retainer;

a force sensor configured to measure a force exerted on the plunger clip by the drive system; and

a control unit operably connected to the drive system and the force sensor, wherein the control unit is configured to;

move the plunger clip away from the syringe retainer using the drive system;

measure the force exerted on the plunger clip by the drive system using the force sensor; and

make a determination that the plunger clip is properly engaged with a plunger of a syringe retained in the syringe retainer if the force measured by the force sensor reaches or exceeds a selected force level while the flow control device prevents flow into the syringe.

2. An apparatus according to claim 1, wherein the control unit is configured to make a determination that the plunger clip is not properly engaged with a plunger of a syringe in the syringe retainer if the force measured by the force sensor has not reached the selected force level after the drive system has moved the plunger clip a selected limit distance.

3. An apparatus according to claim 1, wherein the selected force level is dependent on a distance over which the drive system has moved the plunger clip, wherein the selected force level increases as the distance increases.

4. An apparatus according to claim 1, wherein the control unit is configured to stop the drive system from moving the plunger clip away from the syringe retainer when the selected force level is reached.

5. An apparatus according to claim 1, wherein the control unit is configured to measure the force exerted on the plunger clip by the drive system while the drive system is moving the plunger clip.

6. An apparatus according to claim 1, wherein the control unit is configured to stop the drive system from moving the plunger clip away from the syringe retainer when the drive system has moved the plunger clip over a selected limit distance.

7. An apparatus according to claim 1, wherein the flow control device is configured to selectively close to prevent flow into a syringe retained in the syringe retainer, wherein the flow control device is operably connected to the control unit which is configured to selectively close the flow control device before the plunger clip is moved away from the syringe retainer by the drive system.

8. An apparatus according to claim 7, wherein the flow control device is normally open.

9. An apparatus according to claim 7, wherein the control unit is configured to move the plunger clip forward toward the syringe retainer using the drive system, and wherein the flow control device is normally open when the plunger clip is moving forward toward the syringe retainer.

10. An apparatus according to claim 7, wherein the flow control device comprises a clamp.

11. An apparatus according to claim 7, wherein the flow control device comprises a valve.

12. An apparatus according to claim 1, wherein the flow control device is configured to selectively prevent flow out of the syringe, and wherein the control unit is configured to:

close the flow control device to prevent flow out of the syringe;

move the plunger clip toward the syringe retainer using the drive system while the flow control device is closed;

measure the force exerted on the plunger clip by the drive system using the force sensor; and

make a determination that a syringe is properly connected to a delivery line if the force measured by the force sensor while moving the plunger clip towards the syringe retainer reaches or exceeds a selected delivery force level.

13. An apparatus according to claim 1, wherein an air control apparatus is positioned downstream from an outlet of a syringe in the syringe retainer.

14. A method of detecting engagement between a drive system and a plunger of a syringe in a syringe pump, the method comprising:

moving a plunger clip away from a syringe retainer configured to retain a syringe in a fixed position;

preventing flow into the syringe in the syringe retainer while moving the plunger clip away from the syringe retainer;

measuring a force exerted on the plunger clip while preventing flow into the syringe; and

determining that the plunger clip is properly engaged with the plunger of the syringe in the syringe retainer if the measured force reaches or exceeds a selected force level.

15. A method according to claim 14, wherein the method comprises determining that the plunger clip is not properly engaged with the plunger if the measured force has not reached the selected force level after moving the plunger clip a selected limit distance.

16. A method according to claim 14, wherein the selected force level is dependent on a distance over which the plunger clip moves, and wherein the selected force level increases as the distance increases.

17. A method according to claim 14, wherein the method comprises stopping movement of the plunger clip away from the syringe retainer when the selected force level is reached.

18. A method according to claim 14, wherein the method comprises measuring the force exerted on the plunger clip while moving the plunger clip.

19. A method according to claim 14, wherein preventing flow into the syringe comprises closing a flow control device.

20. A method according to claim 19, wherein the method comprises closing the flow control device before moving the plunger clip away from the syringe retainer.

21. A method according to claim 14, wherein the method comprises moving the plunger clip toward the syringe retainer to a selected position after determining that the plunger clip is properly engaged with the plunger of the syringe in the syringe retainer.

22. A method according to claim 21, wherein the selected position comprises a starting position of the plunger clip, wherein the starting position comprises a position of the plunger clip before moving the plunger clip away from the syringe retainer.

23. A method according to claim 14, wherein the method comprises:

moving the plunger clip toward the syringe retainer while preventing flow out of the syringe;

measuring the force exerted on the plunger clip by the drive system using the force sensor while moving the plunger clip toward the syringe retainer and preventing flow out of the syringe; and

determining that the syringe is properly connected to a delivery line if the force measured by the force sensor while moving the plunger clip towards the syringe retainer reaches or exceeds a selected delivery force level.