Signal Processing Method and Apparatus for Processing a Physiologic Signal such as a Photoplethysmography Signal

• US 20080262326A1
• Filed: 04/21/2008
• Published: 10/23/2008
• Est. Priority Date: 04/19/2007
• Status: Abandoned Application

• Current Assignee: STARR Life Sciences Corp.
• Original Assignee: STARR Life Sciences Corp.
• Inventors: Hete, Bernard F., Ayers, Eric J.
• Application Number:
  US12/106,781
• Publication Number:
  US 20080262326A1
• Time in Patent Office: Days
• US Class Current: 600/323
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/14551 for measuring blood gases

Abstract

A signal processing method of processing a physiologic signal, such as a Photoplethysmography Signal having at least some cardiac components and/or respirator components in the physiologic signal, the processing including the steps of: Identifying a potential cardiac and or respiratory components of a physiologic signal wherein the potential cardiac and or respiratory components have a series of peaks and valleys; Calculating a comparison of the durations of a peak to valley sub-component and a valley to peak sub component of the potential cardiac and or respiratory components; and Utilizing the calculated comparison to evaluate the potential cardiac and or respiratory components.

Claims

1. A signal processing method of processing a physiologic signal having at least some cardiac components in the physiologic signal, the processing including the steps of:

Identifying a potential cardiac component of a physiologic signal wherein the potential cardiac component has a series of peaks and valleys;

Calculating a comparison of the durations of a peak to valley sub-component and a valley to peak sub component of the potential cardiac component; and

Utilizing the calculated comparison to evaluate the potential cardiac component.

2. The signal processing method according to claim 1 wherein the signal includes at least some respiratory components.

3. The signal processing method according to claim 2 wherein the signal is a Photoplethysmography Signal.

4. The signal processing method according to claim 3 wherein the calculated comparison is a ratio of the durations of a peak to valley sub-component and a valley to peak sub component of the potential cardiac component.

5. The signal processing method according to claim 4 wherein the evaluation of the potential cardiac component includes determining whether the calculated ratio is above or below a preset threshold.

6. The signal processing method according to claim 4 wherein the evaluation of the potential cardiac component includes flagging the potential cardiac component when the calculated ratio fails to satisfy a preset threshold.

7. The signal processing method according to claim 4 wherein the calculated comparison includes a calculation of at least a portion of the slopes of the sub-components.

8. A signal processing method of processing a physiologic signal having at least some respiratory and some cardiac components in the physiologic signal, the processing including the steps of:

Identifying a potential respiratory component of a physiologic signal wherein the potential respiratory component has a series of peaks and valleys;

Calculating a comparison of the durations of a peak to valley sub-component and a valley to peak sub component of the potential respiratory component; and

Utilizing the calculated comparison to evaluate the potential respiratory component.

9. The signal processing method according to claim 8 wherein the signal is a Photoplethysmography Signal.

10. The signal processing method according to claim 9 wherein the calculated comparison is a ratio of the durations of a peak to valley sub-component and a valley to peak sub component of the potential respiratory component.

11. The signal processing method according to claim 10 wherein the evaluation of the potential respiratory component includes determining whether the calculated ratio is above or below a preset threshold.

12. The signal processing method according to claim 10 wherein the evaluation of the potential respiratory component includes flagging the potential respiratory component when the calculated ratio fails to satisfy a preset threshold.

13. The signal processing method according to claim 10 wherein the calculated comparison includes a calculation of at least a portion of the slopes of the sub-components.

14. A signal processing method of processing a physiologic Photoplethysmography signal having peaks and valleys in the physiologic signal, the processing including the steps of Calculating a comparison of the durations of a peak to valley sub-component and a valley to peak sub component of the physiologic signal, and utilizing the calculated comparison to evaluate the physiologic signal.

15. The signal processing method according to claim 14 wherein the calculated comparison is a ratio of the durations of a peak to valley sub-component and a valley to peak sub component of the physiologic signal.

16. The signal processing method according to claim 15 wherein the evaluation of the physiologic signal includes determining whether the calculated ratio is above or below a preset threshold.

17. The signal processing method according to claim 15 wherein the evaluation of the physiologic signal includes flagging the physiologic signal when the calculated ratio fails to satisfy a preset threshold.

18. The signal processing method according to claim 15 wherein the calculated comparison includes a calculation of at least a portion of the slopes of the sub-components.

19. The signal processing method according to claim 15 wherein the physiologic signal is a photophethysmography signal of extra thoracic blood flow of the subject.

20. The signal processing method according to claim 15 wherein the physiologic signal is of a small animal.