Method of analyzing and processing signals

• US 10,182,764 B2
• Filed: 06/24/2015
• Issued: 01/22/2019
• Est. Priority Date: 02/27/2003
• Status: Active Grant

• Current Assignee: Nellcor Puritan Bennett Ireland
• Original Assignee: Nellcor Puritan Bennett Ireland
• Inventors: Addison, Paul Stanley, Watson, James Nicholas
• Primary Examiner(s): Winakur, Eric
• Assistant Examiner(s): Fardanesh, Marjan
• Application Number:
  US14/749,481
• Publication Number:
  US 20150366511A1
• Time in Patent Office: 1,308 Days
• Field of Search: None
• CPC Class Codes: A61B 2503/06 Children, e.g. for attention deficit diagnosis
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0082 adapted for particular medical purposes
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• 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
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6829 Foot or ankle
• CPC Class Codes: A61B 5/6838 Clamps or clips
• CPC Class Codes: A61B 5/6896 Toys
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/7214 using signal cancellation, e.g. based on input of two identical physiological sensors spaced apart, or based on two signals derived from the same sensor, for different optical wavelengths
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: G01N 21/3151 using two sources of radiation of different wavelengths G01N21/33 - G01N21/39 take precedence

Abstract

According to embodiments, a system for processing a physiological signals is disclosed. The system may comprise a sensor for generating the physiological signal. The system may comprise a processor configured to receive and process the physiological signal in order to improve interpretation and subsequent analysis of the physiological signal. The processor may be configured to generate a wavelet transform based on the physiological signal. The processor may be configured to determine phase values corresponding to the subject'"'"'s respiration based on the wavelet transform. The processor may be configured to generate a sinusoidal waveform that is representative of the subject'"'"'s breathing based on the phase values. The system may also comprise a display device configured to display the sinusoidal waveform.

Claims

1. A method for processing a photoplethysmograph signal of a subject, comprising:

receiving, using a processor, the photoplethysmograph signal from a sensor comprising at least one light transmitter and a photodetector;

generating, using the processor, a wavelet transform based on the photoplethysmograph signal, wherein the wavelet transform comprises phase information;

determining, using the processor, phase values corresponding to the subject'"'"'s respiration based on the wavelet transform;

identifying a respiration ridge based on the wavelet transform of a pulse band, the pulse band corresponding to a pulse component of the photoplethysmograph signal;

generating, using the processor, a representative sinusoidal waveform based on the phase values and the identified respiration ridge, wherein the representative sinusoidal waveform is representative of the subject'"'"'s breathing; and

displaying, using a display device, the representative sinusoidal waveform.

2. The method of claim 1, wherein determining the phase values comprises determining the phase values based on the wavelet transform and a secondary wavelet transform.

3. The method of claim 1, wherein determining the phase values comprises processing the phase information to remove erroneous phase information caused by movement artifact.

4. The method of claim 1, wherein generating the representative sinusoidal waveform comprises determining the cosine of the phase values.

5. The method of claim 1, further comprising determining, using the processor, a respiration parameter based on the representative sinusoidal waveform.

6. The method of claim 5, wherein the respiration parameter is indicative of a property of an individual breath.

7. The method of claim 1, further comprising determining, using the processor, respiration rate based on the photoplethysmograph signal.

8. A system for processing a photoplethysmograph signal of a subject comprising:

a sensor comprising at least one light transmitter and a photodetector, wherein the sensor is configured to generate the photoplethysmograph signal;

a processor configured to perform operations comprising;

receiving the photoplethysmograph signal from the sensor;

generating a wavelet transform based on the photoplethysmograph signal, wherein the wavelet transform comprises phase information;

determining phase values corresponding to the subject'"'"'s respiration based on the wavelet transform;

identifying a respiration ridge based on the wavelet transform of a pulse band, the pulse band corresponding to a pulse component of the photoplethysmograph signal; and

generating a representative sinusoidal waveform based on the phase values and the identified respiration ridge, wherein the representative sinusoidal waveform is representative of the subject'"'"'s breathing; and

a display device configured for displaying the representative sinusoidal waveform.

9. The system of claim 8, wherein the processor is configured to determine the phase values based on the wavelet transform and a secondary wavelet transform.

10. The system of claim 8, wherein determining the phase values comprises processing the phase information to remove erroneous phase information caused by movement artifact.

11. The system of claim 8, wherein generating the representative sinusoidal waveform comprises determining the cosine of the phase values.

12. The system of claim 8, wherein the processor is configured to perform operations further comprising determining a respiration parameter based on the representative sinusoidal waveform.

13. The system of claim 12, wherein the respiration parameter is indicative of a property of an individual breath.

14. The system of claim 8, wherein the processor is configured to perform operations further comprising determining respiration rate based on the photoplethysmograph signal.