SYSTEMS AND METHODS FOR DETERMINING EFFORT

• US 20090326402A1
• Filed: 10/03/2008
• Published: 12/31/2009
• Est. Priority Date: 06/30/2008
• Status: Abandoned Application

• Current Assignee: Nellcor Puritan Bennett Ireland
• Original Assignee: Nellcor Puritan Bennett Ireland
• Inventors: Addison, Paul Stanley, Watson, James
• Application Number:
  US12/245,366
• Publication Number:
  US 20090326402A1
• Time in Patent Office: Days
• US Class Current: 600/529
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 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 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/726 using Wavelet transforms

Abstract

According to embodiments, methods and systems for determining effort is disclosed. Effort may relate to a measure of strength of at least one repetitive feature in a signal. Effort may also relate to physical effort or work of a process (e.g., respiratory effort) that may affect the signal (e.g., a PPG signal). Effort may be determined through feature analysis of a transformed signal that has been transformed via a continuous wavelet transform. For example, respiratory effort may be determined using a scalogram generated based at least in part on a wavelet transform of a physiological signal and analyzing features of the scalogram.

Claims

1. A method for determining effort, comprising:

transforming a signal to generate a transformed signal;

generating a scalogram based at least in part on the transformed signal;

analyzing one or more features within the scalogram;

determining effort information based at least in part on the one or more analyzed features; and

providing the effort information.

2. The method of claim 1, wherein transforming the signal comprises transforming the signal using a continuous wavelet transform.

3. The method of claim 1, wherein at least one of the one or more features within the scalogram is located in one or more bands within the scalogram.

4. The method of claim 3, wherein the signal is a photoplethysmograph signal, wherein the effort information is breathing effort information, and wherein one of the one or more bands within the scalogram is a breathing band or a pulse band.

5. The method of claim 1, wherein analyzing the one or more features comprises

calculating an energy parameter within a selected region;

and

calculating a second energy parameter from a second selected region, wherein the selected region and the second selected region are different regions, and wherein determining breathing effort information comprises determining a change in breathing effort.

6. The method of claim 5, wherein the selected region and the second selected region are the same size and wherein the second region is shifted in time from the first region.

7. The method of claim 1, wherein the one or more features are selected from the group consisting of:

amplitude;

energy;

amplitude modulation; and

scale modulation.

21. The computer-readable medium of claim 1, wherein the one or more features are selected from the group consisting of:

amplitude;

energy;

amplitude modulation;

scale modulation; and

distances between amplitude peaks of a band.

8. A system for determining effort, comprising:

a sensor capable of generating a signal;

a processor capable of;

transforming the signal;

generating a scalogram based at least in part on the transformed signal;

analyzing one or more features within the scalogram;

determining effort information based at least in part on the one or more analyzing features; and

providing the effort information.

9. The system of claim 8, wherein transforming the signal comprises transforming the signal using a continuous wavelet transform.

10. The system of claim 8, wherein at least one of the one or more features within the scalogram is located in one or more bands within the scalogram.

11. The system of claim 10, wherein the signal is a photoplethysmograph signal, wherein the effort information is breathing effort information, and wherein one of the one or more bands within the scalogram is a breathing band or a pulse band.

12. The system of claim 8, wherein analyzing the one or more features comprises:

calculating an energy parameter within a selected region; and

calculating a second energy parameter from a second selected region, wherein the selected region and the second selected region are different regions, and wherein determining breathing effort information comprises determining a change in breathing effort.

13. The system of claim 12, wherein the selected region and the second selected region are the same size and wherein the second region is shifted in time from the first region.

14. The system of claim 8, wherein the one or more features are selected from the group consisting of:

amplitude;

energy;

amplitude modulation; and

scale modulation.

15. A computer-readable medium for determining effort, the computer-readable medium having computer program instructions recorded thereon for:

transforming a signal to generate a transformed signal;

generating a scalogram based at least in part on the transformed signal;

analyzing one or more features within the scalogram;

determining effort information based at least in part on the one or more analyzed features; and

providing the effort information.

16. The computer-readable medium of claim 15, wherein transforming the signal comprises transforming the signal using a continuous wavelet transform.

17. The computer-readable medium of claim 15, wherein at least one of the one or more features within the scalogram is located in one or more bands within the scalogram.

18. The computer-readable medium of claim 17, wherein the signal is a photoplethysmograph signal, wherein the effort information is breathing effort information, and wherein one of the one or more bands within the scalogram is a breathing band or a pulse band.

19. The computer-readable medium of claim 15, wherein analyzing the one or more features comprises:

calculating an energy parameter within a selected region; and

calculating a second energy parameter from a second selected region, wherein the selected region and the second selected region are different regions, and wherein determining breathing effort information comprises determining a change in breathing effort.

20. The computer-readable medium of claim 19, wherein the selected region and the second selected region are the same size and wherein the second region is shifted in time from the first region.