Pressure Sensor and Method of Use

• US 20120203179A1
• Filed: 08/09/2011
• Published: 08/09/2012
• Est. Priority Date: 08/11/2010
• Status: Active Grant

• Current Assignee: Zevex (Moog Incorporated)
• Original Assignee: Zevex (Moog Incorporated)
• Inventors: Stringham, Mark, Allen, Blake, Hills, Chris
• Granted Patent: US 8,486,020 B2
• Time in Patent Office: Days
• US Class Current: 604/151
• CPC Class Codes: A61M 5/16831 Monitoring, detecting, signalling or eliminating infusion flow anomalies low-level float-valves causing cut-off A61M5/40; indicating or recording presence, absence or direction of flow in general G01P13/0066
• CPC Class Codes: A61M 5/16854 by monitoring line pressure

Abstract

A sensor and method of use provides for detection of an occlusion (or sudden pressure increase) in tubing during the administration of solutions to a patient. The occlusion sensor may be attached to an infusion pump using a biasing mechanism. The tubing may be positioned in contact with the occlusion sensor using a cassette. Detection of an occlusion in the tubing is accomplished by measuring the compression and expansion of the tubing. When the tubing becomes occluded pressure within the tube will increase, resulting in expansion of the tubing. Expansion of the tubing exerts a force on the sensor to trigger an alarm to alert medical personnel of the occluded tube.

Claims

1. A pressure sensor system comprising:

a sensor for measuring the pressure inside a structure; and

a movable plunger disposed in communication with the structure and the sensor, wherein the movable plunger applies a force against the sensor and is oriented so that, the magnitude of the force applied to the sensor by the movable plunger changes relative to a change in pressure inside the structure.

2. A system for measuring pressure including the occlusion sensor system according to claim 1, further comprising the structure, wherein the structure comprises tubing of an infusion set.

3. A system for measuring pressure according to claim 2, wherein the sensor is disposed on a pump having a pump mechanism, and wherein the tubing is positioned adjacent the sensor and the pump such that the tubing is in communication with the movable plunger and the pump mechanism.

4. The system for measuring pressure according to claim 3, further comprising a biasing mechanism which biases the occlusion sensor toward the plunger.

5. The system of claim 4, further comprising a pump body and wherein the occlusion sensor is attached to the pump body so as to allow movement of the occlusion sensor relative to the pump body.

6. The pressure sensor system according to claim 1, further comprising a collar, wherein the movable plunger extends through an opening in the collar to contact the structure whose pressure is being measured.

7. The pressure sensor system according to claim 6, wherein the structure is tubing of an infusion set and wherein the occlusion sensor further comprises a collar disposed about the plunger and a biasing mechanism which biases the occlusion sensor toward the plunger and biases the collar into engagement with tubing when the tubing is mounted adjacent the occlusion sensor, and wherein the collar limits the distance that the movable plunger extends through the opening in the collar and protrudes into the tubing.

8. The pressure sensor system according to claim 7, wherein the plunger partially collapses the tubing in an ambient state.

9. A system for measuring pressure including the occlusion sensor system according to claim 6, and further comprising a pump to which the occlusion sensor is connected and a cassette for receiving tubing of an infusion set, wherein the cassette connects to the pump.

10. The system for measuring pressure according to claim 9, wherein the cassette comprises at least one retaining member, and wherein the biasing mechanism biases the collar into engagement with the at least one retaining member.

11. The system for measuring pressure according to claim 10, wherein the retaining member limits movement of the tubing in a directional generally perpendicular to the movement of the plunger.

12. The pressure sensor system of claim 1, wherein the sensor is directly mounted on a circuit board.

13. An infusion system comprising:

a pump configured to receive tubing of an infusion set;

a sensor system disposed on the pump, the sensor system comprising a sensor and a plunger disposed to extend away from the sensor to transmit force from the tubing of the infusion set to the sensor;

wherein when tubing of an infusion set is mounted on the pump, the tubing exerts a force on the sensor via the plunger, the force changing relative to the pressure in the infusion set.

14. The infusion system according to claim 13, wherein the sensor is directly disposed on a circuit board and the plunger is forced against the sensor responsive to pressure in the tubing.

15. The infusion system according to claim 13, further comprising a collar having an opening, wherein the plunger extends through the opening.

16. The infusion system according to claim 13, further comprising an infusion set, the infusion set comprising tubing and a cassette which holds the tubing to the pump

17. The infusion system according to claim 16, further comprising a collar disposed adjacent the plunger and wherein the cassette has retaining members, and wherein the collar engages the retaining members when the cassette is operably connected to the pump.

18. The infusion system according to claim 17, wherein the retaining members contact the collar and limit expansion of the tubing.

19. The infusion system according to claim 13, wherein the sensor is mounted to the pump using a mounting plate and a biasing mechanism to allow the sensor to move relative to the pump.

20. The infusion system according to claim 13, further comprising an infusion set having tubing and wherein the plunger partially collapses the tubing in an ambient state.

21. A method for detecting pressure in tubing the method comprising:

selecting an infusion pump having a sensor disposed thereon and a plunger disposed in communication with the sensor to transfer force to the sensor;

connecting tubing of an infusion set adjacent the infusion pump so that the tubing is in communication with the plunger to thereby change the force transferred by the plunger to the sensor; and

detecting an occlusion by measuring changes in pressure within the tubing communicated to the sensor via the plunger.

22. The method according to claim 21, wherein the method further comprises the step of selecting a cassette configured to receive the tubing of the infusion set and attaching the cassette to the infusion pump.

23. The method according to claim 21, wherein the method further comprises the step of attaching the occlusion sensor to the infusion pump using a biasing mechanism to allow movement between the sensor and the pump.

24. The method according to claim 21, wherein the method comprises selecting a sensor formed by a piezoresistive sensor.

25. The method according to claim 21, wherein the method comprises using an infusion pump having a collar with an opening for receiving the plunger and wherein the cassette has at least one retaining member and wherein attaching the cassette to the infusion pump causes at least one retaining member of the cassette to come into engagement with the collar.

26. The method of claim 21, wherein the method comprises disposing the plunger against the tubing so as to partially collapses the tubing in a normal operating state.

27. An sensor system for used on a pump which pumps fluid through a tubing, the system comprising:

a pump having a pump body; and

a sensor attached to the pump body and having a biasing mechanism which biases the sensor toward tubing when tubing is mounted on the pump.

28. The sensor system of claim 27, wherein the system comprises a plunger disposed adjacent the sensor for transferring force to the sensor.

29. The sensor system of claim 28, wherein the system comprises a support structure adjacent the plunger.

30. The sensor system of claim 29, wherein the support structure is a collar.

31. The sensor system of claim 30, wherein the collar has an opening and wherein the plunger extends through the opening.

32. The sensor system of claim 27, wherein the sensor is disposed on a printed circuit board.