DRAINAGE PUMP UNIT

• US 20120184932A1
• Filed: 01/16/2012
• Published: 07/19/2012
• Est. Priority Date: 01/17/2011
• Status: Active Grant

• Current Assignee: Medela Holding AG (Olle Larsson Holding AG)
• Original Assignee: Medela Holding AG (Olle Larsson Holding AG)
• Inventors: Giezendanner, Charles, Melzer, Martin
• Granted Patent: US 9,333,281 B2
• Time in Patent Office: Days
• US Class Current: 604/319
• CPC Class Codes: A61M 1/73 comprising sensors or indicators for physical values
• CPC Class Codes: A61M 1/74 Suction control underwater drainage A61M1/61
• CPC Class Codes: A61M 1/80 Suction pumps A61M1/64, A61M1/71, A61M60/00 take precedence
• CPC Class Codes: A61M 1/982 with means for detecting level of collected exudate
• 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: G01F 23/266 measuring circuits therefor
• CPC Class Codes: G01F 23/268 mounting arrangements of probes

Abstract

A drainage pump unit for aspirating body fluids by means of a suction pump has a suction pump arranged in a suction pump housing, wherein a fluid collection container can be secured releasably on the suction pump housing, and wherein a capacitive filling level sensor is arranged on the suction pump housing for detecting a filling level in the fluid collection container. The filling level sensor has at least two electrodes, which are arranged at a distance from each other and extend along a common path. A first of the electrodes is in one piece, and a second of the electrodes is segmented. This arrangement permits the production of inexpensive fluid collection containers while still ensuring a high degree of measurement accuracy.

Claims

1. A drainage pump unit for aspirating body fluids by means of a suction pump, comprising:

a suction pump arranged in a suction pump housing, wherein a fluid collection container can be secured releasably on the suction pump housing, and wherein a capacitive filling level sensor is arranged on the suction pump housing for detecting a filling level in the fluid collection container, wherein the filling level sensor has at least two electrodes arranged at a distance from each other and extend along a common path, wherein a first of the at least two electrodes is in one piece, and at least a second of the at least two electrodes is segmented, wherein the one-piece first electrode comprises a transmitter electrode and the segmented second electrode comprises a receiver electrode, wherein an excitation signal can be applied by a modulator to the one-piece first electrode.

2. The drainage pump unit according to claim 1, wherein the excitation signal can be coupled capacitively into the segmented second electrode.

3. The drainage pump unit according to claim 1, wherein the electrodes extend along approximately an entire fillable height of the fluid collection container.

4. The drainage pump unit according to claim 1, wherein the at least two electrodes are arranged next to each other in a common plane, or wherein the at least two electrodes lie opposite each other.

5. The drainage pump unit according to claim 1, wherein the at least two electrodes are arranged in or on a wall of the suction pump housing, wherein the wall faces towards the fluid collection container in an intended position of use.

6. The drainage pump unit according to claim 1, wherein the at least one segmented electrode is divided into segments which are electrically insulated from one another and are arranged with a spacing of less than 1 mm between one another.

7. The drainage pump unit according to claim 1, further comprising an electronics system, wherein one of the electrodes can be excited with an oscillating first signal from the electronics system.

8. The drainage pump unit according to claim 7, wherein the first signal includes a sinusoidal function.

9. The drainage pump unit according to claim 7, wherein the excitation takes place at a frequency in the range of 4 to 5 MHz.

10. The drainage pump unit according to claim 7, wherein the excitation takes place at a frequency of 4 MHz.

11. The drainage pump unit according to claim 7 wherein the excitation takes place at a frequency of 4.75 MHz.

12. The drainage pump unit according to claim 7, wherein the electronics system is configured to excite the excitable electrode with an oscillating second signal.

13. The drainage pump unit according to claim 12, wherein the excitation takes place at a frequency of approximately 100 kHz.

14. The drainage pump unit according claim 1, wherein the at least one segmented second electrode is divided into more than three segments.

15. The drainage pump unit according to claim 14, wherein the at least one segmented second electrode is divided into eight segments.

16. The drainage pump unit according to claim 1, wherein the at least two electrodes are band-shaped.

17. The drainage pump unit according to claim 1, wherein the at least two electrodes are copper-coated circuit boards.

18. The drainage pump unit according to claim 1, wherein the at least two electrodes are arranged on a single printed circuit board.

19. The drainage pump unit according to claim 1, wherein the at least two electrodes are arranged on an inner wall of the suction pump housing.

20. The drainage pump unit according to claim 17, wherein the inner wall of the suction pump housing has a depression for receiving the at least two electrodes, said depression being so dimensioned that the at least two electrodes do not protrude from the inner wall in the direction of the container interior.

21. A filling level sensor for use in a drainage pump unit, the drainage pump unit comprising a suction pump arranged in a suction pump housing, wherein a fluid collection container can be secured releasably on the suction pump housing, and wherein the filling level sensor is arranged on the suction pump housing for detecting a filling level in the fluid collection container, wherein the filling level sensor has at least two electrodes arranged next to each other in a common plane and at a distance from each other, the at least two electrodes extending along a common path, wherein a first of the at least two electrodes is in one piece and at least a second of these electrodes is segmented and wherein the one-piece first electrode is a transmitter electrode and the segmented second electrode is a receiver electrode, wherein an excitation signal can be applied by a modulator to the one-piece first electrode.

22. The filling level sensor according to claim 21, wherein the excitation signal can be coupled capacitively into the segmented second electrode.