Systems And Methods For Wavelet Transform Scale-Dependent Multiple-Archetyping

• US 20110276275A1
• Filed: 05/04/2010
• Published: 11/10/2011
• Est. Priority Date: 05/04/2010
• Status: Active Grant

• Current Assignee: Nellcor Puritan Bennett Ireland
• Original Assignee: Nellcor Puritan Bennett Ireland
• Inventors: Addison, Paul, Watson, James, Ochs, James
• Granted Patent: US 9,050,043 B2
• Time in Patent Office: Days
• US Class Current: 702/19
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: G06F 2218/02 Preprocessing

Abstract

Methods and systems are disclosed for producing a plurality of archetype signals in wavelet space at a plurality of wavelet scales. A signal is transformed using a continuous wavelet transform based at least in part on a wavelet function. A scale dependent archetype transformed signal is computed based at least in part on the transformed signal and based at least in part on a natural periodicity of the wavelet function used to transform the signal. Information may be derived about the signal from the archetype transform signal, and stored in memory.

Claims

1. A method for processing a signal, comprising:

receiving the signal;

using specialized processing hardware and software for;

transforming the signal using a continuous wavelet transform to generate a transformed signal, wherein the continuous wavelet transform is based at least in part on a wavelet function,

computing an archetype transformed signal based at least in part on the transformed signal and based at least in part on a natural periodicity of the wavelet function used to transform the signal;

deriving information about the signal from the archetype transform signal; and

storing the information in electronic memory;

2. The method of claim 1, wherein the archetype transform signal is computed using a weighted averaging scheme, the weighted averaging scheme comprising:

at least one weight variable; and

a delay time.

3. The method of claim 2, wherein the at least one weight variable is chosen based at least in part on a signal condition.

4. The method of claim 2, wherein the delay time is based at least in part on the natural periodicity of the wavelet function at a scale of the wavelet function.

5. The method of claim 1, wherein the archetype transform signal is derived at each scale of interest.

6. The method of claim 1, wherein the archetype transform signal is derived continuously over a range of scales.

7. The method of claim 1, further comprising:

generating an archetype scalogram based at least in part on the archetype transform signal; and

deriving information about the signal from the archetype scalogram.

8. The method of claim 1, further comprising:

generating a first scalogram based at least in part on the transform signal.

9. The method of claim 1, wherein the information comprises physiological information.

10. The method of claim 9, wherein the physiological information comprises pulse rate and/or oxygen saturation and/or a combination thereof.

11. The method of claim 1, wherein the signal comprises a photoplethysmograph (PPG) signal.

12. A system for processing a signal, comprising:

a receiver that receives the signal;

specialized processing hardware and software for;

transforming the signal using a continuous wavelet transform to generate a transformed signal, wherein the continuous wavelet transform is based at least in part on a wavelet function,

computing an archetype transformed signal based at least in part on the transformed signal and based at least in part on a natural periodicity of the wavelet function used to transform the signal;

deriving information about the signal from the archetype transform signal; and

memory that stores the information;

13. The system of claim 12, wherein the archetype transform signal is computed using a weighted averaging scheme, the weighted averaging scheme comprising:

at least one weight variable; and

a delay time.

14. The system of claim 13, wherein the at least one weight variable is chosen based at least in part on a signal condition.

15. The system of claim 13, wherein the delay time is based at least in part on the natural periodicity of the wavelet function at a scale of the wavelet function.

16. The system of claim 12, wherein the archetype transform signal is derived at each scale of interest.

17. The system of claim 12, wherein the archetype transform signal is derived continuously over a range of scales.

18. The system of claim 12, wherein the specialized processing hardware and software is further capable of:

generating an archetype scalogram based at least in part on the archetype transform signal; and

deriving information about the signal from the archetype scalogram.

19. The system of claim 12, wherein the information comprises physiological information.

20. The method of claim 19, wherein the physiological information comprises pulse rate and/or oxygen saturation and/or a combination thereof.