CAPACITIVE FLUID LEVEL SENSING

• US 20100121257A1
• Filed: 11/07/2008
• Published: 05/13/2010
• Est. Priority Date: 11/07/2008
• Status: Active Grant

• Current Assignee: Johnson & Johnson Surgical Vision, Inc. (Johnson & Johnson)
• Original Assignee: Advanced Medical Optics Incorporated (Johnson & Johnson)
• Inventors: King, David A.
• Granted Patent: US 8,469,050 B2
• Time in Patent Office: Days
• US Class Current: 604/22
• CPC Class Codes: A61F 9/00745 using mechanical vibrations, e.g. ultrasonic
• CPC Class Codes: A61M 1/63 with means for emptying the suction container, e.g. by interrupting suction
• CPC Class Codes: A61M 1/631 Emptying the suction container without interrupting suction
• CPC Class Codes: A61M 1/72 Cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 1/74 Suction control underwater drainage A61M1/61
• CPC Class Codes: A61M 1/77 Suction-irrigation systems aspiration tips supplying fluids A61M1/85; specific for negative pressure wound therapy A61M1/92; combined with tracheal tubes A61M16/0463
• CPC Class Codes: A61M 2205/123 with incorporated reservoirs
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3382 Upper level detectors
• CPC Class Codes: A61M 2205/3386 Low level detectors
• CPC Class Codes: A61M 2205/3389 Continuous level detection A61M2205/3393 takes precedence
• CPC Class Codes: A61M 3/0201 Cassettes therefor
• CPC Class Codes: A61M 31/00 Devices for introducing or retaining media, e.g. remedies, in cavities of the body A61M25/00 takes precedence ; introducing or retaining ophthalmic products into the ocular cavities A61F9/0008
• CPC Class Codes: G01F 23/265 for discrete levels
• CPC Class Codes: G01F 23/266 measuring circuits therefor
• CPC Class Codes: G01F 23/268 mounting arrangements of probes
• CPC Class Codes: Y10T 137/7306 Electrical characteristic sensing

Abstract

A capacitive fluid level sensing arrangement for use in a medical device is provided. The arrangement includes at least one pair of conductive plates configured to increase and decrease the amount of electric charge stored in relation to the level of fluid within a fluid maintaining device, such as a reservoir. The conductive plates are electrically connected to a medical device and are configured to measure the charge stored between the plates and thus sense the fluid level. The electric circuit may communicate the measurement to an instrument host arrangement for operating a pump configured to remove fluid from the reservoir and move the fluid to a collector when the level exceeds a preset upper level amount. The instrument host arrangement may stop operating the pump when the fluid level is reduced to a preset lower level amount.

Claims

1. A medical device, comprising:

a plurality of conductive plates forming a sensor positioned in association with a fluid maintaining device associated with the medical device; and

a controller configured to receive data from the plurality of conductive plates forming the sensor;

wherein the plurality of conductive plates are configured to sense fluid changes in the fluid maintaining device and provide data to the controller, and further wherein the controller is configured to facilitate fluid evacuation from the fluid maintaining device associated with the medical device based on data received from the plurality of conductive plates.

2. The medical device of claim 1, wherein the plurality of conductive plates comprises multiple pairs of conductive plates.

3. The medical device of claim 1, wherein the fluid maintaining device comprises a reservoir housed within a cassette.

4. The medical device of claim 1, wherein the fluid maintaining device comprises a reservoir, and wherein the plurality of conductive plates are positioned external to the reservoir located within the medical device.

5. The medical device of claim 1, wherein the fluid maintaining device comprises a reservoir, and the plurality of conductive plates are positioned within the reservoir located within the medical device.

6. The medical device of claim 1, wherein the fluid maintaining device comprises a reservoir, and the plurality of conductive plates are integrated with the medical device and positioned in close proximity to the reservoir configured to be positioned within the medical device.

7. The medical device of claim 1, wherein the plurality of conductive plates and controller are configured to sense an increased fluid level in the fluid maintaining device and evacuate fluid from the fluid maintaining device subsequent to sensing the increased fluid level.

8. The medical device of claim 1, wherein the plurality of conductive plates is conductive and forms a capacitive sensor wherein capacitance is proportional to permittivity of dielectric material between the plates, wherein the dielectric material comprises the fluid.

9. The medical device of claim 1, wherein the plurality of conductive plates and controller are configured to sense a decreased fluid level in the fluid maintaining device, causing at least one selected from the group consisting of:

termination of fluid removal; and

providing fluid to the fluid maintaining device subsequent to sensing the decreased fluid level.

10. The medical device of claim 1, wherein the plurality of conductive plates comprises a plurality of interleaved conductive plates.

11. The medical device of claim 1, wherein the medical device is an ophthalmic surgical device.

12. The medical device of claim 11, wherein the ophthalmic surgical device is a phacoemulsification system.

13. A fluid level sensing arrangement, comprising:

a pair of conductive plates positioned in association with a fluid maintaining device; and

a controller electrically connected to the pair of conductive plates;

wherein the controller is configured to sense electrical changes in the pair of conductive plates based on different volumes of fluid and selectively provide fluid to and evacuate fluid from the fluid maintaining device based on the controller sensing electrical changes in the pair of conductive plates.

14. The fluid level sensing arrangement of claim 13, further comprising an additional pair of conductive plates, wherein the pair of conductive plates and the additional pair of conductive plates are employed to sense different fluid levels in the fluid maintaining device.

15. The fluid level sensing arrangement of claim 13, wherein the pair of conductive plates is positioned external to the fluid maintaining device.

16. The fluid level sensing arrangement of claim 13, wherein the pair of conductive plates and controller are configured to sense an increased fluid level in the fluid maintaining device and evacuate fluid from the fluid maintaining device subsequent to sensing the increased fluid level.

17. The fluid level sensing arrangement of claim 13, wherein the pair of conductive plates are conductive and form a capacitive sensor wherein capacitance is proportional to permittivity of dielectric material between the plates, wherein the dielectric material comprises the fluid.

18. The fluid level sensing arrangement of claim 13, wherein the pair of conductive plates and controller are configured to sense a decreased fluid level in the fluid maintaining device and cause fluid to be provided to the fluid maintaining device subsequent to sensing the decreased fluid level.

19. The fluid level sensing arrangement of claim 13, wherein the pair of conductive plates comprises a pair of interleaved conductive plates.

20. The fluid level sensing arrangement of claim 13, wherein the fluid level sensing arrangement is part of an ophthalmic surgical device.

21. The fluid level sensing arrangement of claim 20, wherein the ophthalmic surgical device is a phacoemulsification system.

22. A surgical system, comprising:

a controller configured to receive electrical signals and effectuate controlled functionality of the surgical system;

a reservoir configured to contain fluid usable in performing a medical procedure;

a capacitive sensing device associated with the reservoir and configured to sense fluid level in the reservoir; and

electrical connections between the controller and the capacitive sensing device;

wherein the capacitive sensing device is configured to sense changes in fluid level in the reservoir, convey sensed changes to the controller via the electrical connections, and the controller is configured to selectively alter fluid level in the reservoir based on sensed changes received from the capacitive sensing device via the electrical connections.

23. The surgical system of claim 22, wherein the capacitive sensing device comprises a pair of conductive plates.

24. The surgical system of claim 23, wherein the capacitive sensing device comprises an additional pair of conductive plates, wherein the pair of conductive plates and the additional pair of conductive plates are employed to sense different fluid levels in the reservoir.

25. The surgical system of claim 22, wherein the capacitive sensing device is positioned in association with the reservoir.

26. The surgical system of claim 22, wherein the capacitive sensing device is positioned external to the reservoir.

27. The surgical system of claim 22, wherein the capacitive sensing device and controller are configured to sense an increased fluid level in the reservoir and evacuate fluid from the reservoir subsequent to sensing the increased fluid level.

28. The surgical system of claim 22, wherein the capacitive sensing device is configured to sense capacitance and the capacitance is proportional to permittivity of dielectric material between the two conductive plates, wherein the dielectric material comprises the fluid.

29. The surgical system of claim 22, wherein the capacitive sensing device and controller are configured to sense a decreased fluid level in the reservoir, causing at least one selected from the group consisting of:

termination of fluid removal; and

providing fluid to the reservoir subsequent to sensing the decreased fluid level.

30. The surgical system of claim 22, wherein the pair of conductive plates comprises a pair of interleaved conductive plates.

31. The surgical system of claim 22, wherein the surgical system is used during an ocular surgical procedure.

32. The surgical system of claim 31, wherein the ocular surgical procedure is phacoemulsification.

33. A method for performing a surgical procedure, comprising:

capacitively sensing fluid level within a medical device configured to be employed to perform the surgical procedure; and

depending on fluid level sensed by said capacitively sensing, selectively altering fluid amount within the medical device by selectively evacuating fluid and selectively adding fluid based on the capacitively sensing.

34. The method of claim 33, wherein the medical device is an ophthalmic surgical device.

35. The method of claim 34, wherein the ophthalmic surgical device is a phacoemulsification system.