METHOD OF ANALYZING AND PROCESSING SIGNALS

• US 20130046157A1
• Filed: 08/20/2012
• Published: 02/21/2013
• Est. Priority Date: 02/27/2003
• Status: Abandoned Application

• Current Assignee: Nellcor Puritan Bennett Ireland
• Original Assignee: Nellcor Puritan Bennett Ireland
• Inventors: Addison, Paul Stanley, Watson, James Nicholas
• Application Number:
  US13/590,112
• Publication Number:
  US 20130046157A1
• Time in Patent Office: Days
• US Class Current: 600/323
• 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

A physiological measurement system is disclosed which can take a pulse oximetry signal such as a photoplethysmogram from a patient and then analyse the signal to measure physiological parameters including respiration, pulse, oxygen saturation and movement. The system comprises a pulse oximeter which includes a light emitting device and a photodetector attachable to a subject to obtain a pulse oximetry signal; analogue to digital converter means arranged to convert said pulse oximetry signal into a digital pulse oximetry signal; signal processing means suitable to receive said digital pulse oximetry signal and arranged to decompose that signal by wavelet transform means; feature extraction means arranged to derive physiological information from the decomposed signal; an analyser component arranged to collect information from the feature extraction means; and data output means arranged in communication with the analyser component.

Claims

1-100. -100. (canceled)

101. A method for determining a physiological respiratory anomaly, comprising:

obtaining a biosignal from a subject at least in part using a signal acquisition unit;

decomposing the biosignal at least in part using a wavelet transform analysis;

acquiring a set of measurements that comprise at least one of an oxygen saturation, a respiration rate, a pulse rate, and a physiological movement, based at least in part on the wavelet transform analysis; and

detecting the physiological respiratory anomaly based at least in part on the set of measurements.

102. The method of claim 101, wherein the signal acquisition unit comprises a photodetector and wherein the biosignal is a photoplethysmogram signal.

103. The method of claim 101, wherein detecting the physiological respiratory anomaly is based at least in part on a decrease in the pulse rate.

104. The method of claim 101, wherein detecting the physiological respiratory anomaly is based at least in part on a decrease in the oxygen saturation.

105. The method of claim 101, wherein detecting the physiological respiratory anomaly is based at least in part on a decrease in the respiration rate.

106. The method of claim 105, wherein the decrease in the respiration rate comprises a cessation of breathing for greater than 20 seconds.

107. The method of claim 101, wherein the physiological respiratory anomaly is at least one of apnea, cessation in breathing, excessively slow breathing, excessively fast breathing, sharp intakes of breaths, and coughing.

108. The method of claim 101, wherein the wavelet transform analysis comprises a wavelet ratio analysis.

109. The method of claim 101, wherein the wavelet transform analysis comprises plotting a plurality of Lissajous plots.

110. The method of claim 101, further comprising triggering an alarm based at least in part on the determined physiological respiratory anomaly.

111. A monitoring system for determining a physiological respiratory anomaly, the system comprising:

a signal acquisition unit attachable to a subject to obtain a biosignal; and

a signal processor configured to;

decompose the biosignal at least in part using a wavelet transform analysis, based at least in part on a wavelet function;

acquire a set of measurements that comprise at least one of an oxygen saturation, a respiration rate, a pulse rate, and a physiological movement, based at least in part on the wavelet transform analysis; and

detect the physiological respiratory anomaly based at least in part on the set of measurements.

112. The system of claim 111, wherein the signal acquisition unit comprises a photodetector and wherein the biosignal is a photoplethysmogram signal.

113. The system of claim 111, wherein the signal processor is configured to detect the physiological respiratory anomaly based at least in part on a decrease in the pulse rate.

114. The system of claim 111, wherein the signal processor is configured to detect the physiological respiratory anomaly based at least in part on a decrease in the oxygen saturation.

115. The system of claim 111, wherein the signal processor is configured to detect the physiological respiratory anomaly based at least in part on a decrease in the respiration rate.

116. The system of claim 115, wherein the decrease in the respiration rate comprises a cessation of breathing for greater than 20 seconds.

117. The system of claim 111, wherein the physiological respiratory anomaly is at least one of apnea, cessation in breathing, excessively slow breathing, excessively fast breathing, sharp intakes of breaths, and coughing.

118. The system of claim 111, wherein the wavelet transform analysis comprises a wavelet ratio analysis.

119. The system of claim 111, wherein the wavelet transform analysis comprises plotting a plurality of Lissajous plots.

120. The system of claim 111, wherein the signal processor is further configured to trigger an alarm based at least in part on the determined physiological respiratory anomaly.