Integrated Pulse Oximeter-Pulse Flowmeter

• US 20110060201A1
• Filed: 09/08/2009
• Published: 03/10/2011
• Est. Priority Date: 09/08/2009
• Status: Abandoned Application

• Current Assignee: Lloyd A. Marks, Michael Smith
• Original Assignee: Lloyd A. Marks, Michael Smith
• Inventors: Marks, Lloyd A., Smith, Michael
• Application Number:
  US12/555,400
• Publication Number:
  US 20110060201A1
• Time in Patent Office: Days
• US Class Current: 600/324
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: A61B 5/14551 for measuring blood gases

Abstract

This device uses electrical impedance and signal processing to measure the small change in volume (“Pulse Volume”) of a limb-segment that occurs with each heartbeat. “Pulsatile Flow” is defined as the pulse volume multiplied by the heart rate and is an index of tissue perfusion. This information can be combined with measured blood oxygen saturation to determine how much oxygen is reaching the tissues. The combination of knowing oxygen saturation and tissue perfusion is far more useful than knowing just one or the other of these parameters.

Claims

1. A system for providing oxygenation and perfusion data relating to bodily tissues in a patient, the system comprising:

an oximeter for measuring oxygen saturation in the patient'"'"'s blood; and

an electrode for measuring a flow of the blood through the bodily tissues.

2. The system of claim 1, wherein the oximeter comprises a light source and a light sensor.

3. The system of claim 2, wherein the light source and the light sensor are integrated into the electrode.

4. The system of claim 3, wherein the electrode comprises an impedance electrode.

5. The system of claim 4, wherein the electrode comprises a quadripolar impedance electrode.

6. The system of claim 1, wherein the electrode comprises an impedance electrode.

7. The system of claim 6, wherein the electrode comprises a quadripolar impedance electrode.

8. The system of claim 1, wherein the processor is programmed to adjust an amplitude of a pulse oximetry curve to an measurement of pulse volume.

9. The system of claim 1, further comprising a processor which is programmed to process the measured saturation and flow.

10. The system of claim 9, wherein the processor is programmed to derive a gating signal from an optical plethysmogram curve and to use the gating signal in selective signal averaging of a pulsatile waveform.

11. The system of claim 10, wherein the optical plethysmogram curve is generated by the oximeter.

12. The system of claim 11, wherein the oximeter comprises a plurality of oximetry probes, and wherein the processor uses signals from the plurality of oximetry probes to derive the gating signal when one of the oximetry probes provides a bad signal.

13. The system of claim 12, wherein the processor derives the gating signal by selecting a good signal from another one of the oximetry probes.

14. The system of claim 12, wherein the processor derives the gating signal by adding the signals from the plurality of oximetry probes.

15. The system of claim 9, wherein the processor is programmed to derive an index of tissue oxygenation from the measured saturation and flow.

16. The system of claim 1, further comprising a display.

17. The system of claim 16, wherein the display is configured to display at least one of a pulse oximetry curve and a pulse volume curve.

26. The method of claim 17, wherein step (c) comprises deriving a gating signal from an optical plethysmogram curve and to using the gating signal in selective signal averaging of a pulsatile waveform.

27. The method of claim 26, wherein the optical plethysmogram curve is generated by the oximeter.

28. The method of claim 27, wherein the oximeter comprises a plurality of oximetry probes, step (a) is performed using the plurality of oximetry probes, the gating signal is derived from signals from the plurality of oximetry probes when one of the oximetry probes provides a bad signal.

29. The method of claim 28, wherein the gating signal is derived by selecting a good signal from another one of the oximetry probes.

30. The method of claim 28, wherein the gating signal is derived by adding the signals from the plurality of oximetry probes.

18. A method for measuring oxygenation of bodily tissues in a patient, the method comprising:

(a) measuring oxygen saturation in the patient'"'"'s blood, using an oximeter;

(b) measuring a flow of the blood through the bodily tissues, using an electrode; and

(c) providing information relating to the oxygenation in a processor in accordance with the oxygen saturation and the flow of the blood.

19. The method of claim 18, wherein the oximeter comprises a light source and a light sensor.

20. The method of claim 19 wherein the light source and the light sensor are integrated into the electrode.

21. The method of claim 20 wherein the electrode comprises an impedance electrode.

22. The method of claim 21, wherein the electrode comprises a quadripolar impedance electrode.

23. The method of claim 18, wherein the electrode comprises an impedance electrode.

24. The method of claim 23, wherein the electrode comprises a quadripolar impedance electrode.

25. The method of claim 18, wherein step (c) comprises adjusting an amplitude of a pulse oximetry curve to an measurement of pulse volume.

31. The method of claim 18, wherein step (c) comprises deriving an index of tissue oxygenation from the measured saturation and flow.

32. The method of claim 18, further comprising displaying at least one of a pulse oximetry curve and a pulse volume curve.