APNEA ANALYSIS SYSTEM AND METHOD

• US 20150190088A1
• Filed: 01/06/2015
• Published: 07/09/2015
• Est. Priority Date: 01/07/2014
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Chen, Bo, Kadlec, Ron J., Maharajh, Niranjan, Ochs, James P., Addison, Paul Stanley, Watson, James N., Mestek, Michael L., Kolnsberg, Mark E., Johnson, Corinne H.
• Granted Patent: US 9,848,820 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• 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 5/0826 Detecting or evaluating apnoea events A61B5/4818 takes precedence
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7235 Details of waveform analysis A61B5/349 takes precedence
• CPC Class Codes: A61B 5/7253 characterised by using 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: 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 7/003 Detecting lung or respiration noise

Abstract

An apnea analysis system may include a photoplethysmographic (PPG) sub-system, a breath detection sub-system, and an apnea analysis module. An apnea analysis system includes a photoplethysmographic (PPG) sub-system, a breath detection sub-system, and an apnea analysis module. The PPG sub-system is configured to be operatively connected to an individual and output a PPG signal from the individual. The breath detection sub-system is configured to be operatively connected to the individual and output a breath signal from the individual. The apnea analysis module is in communication with the PPG sub-system and the breath detection sub-system. The apnea analysis module analyzes the breath signal and a respiratory component of the PPG signal and, based on the analysis, identifies a presence of apnea, differentiates between obstructive apnea and central apnea, and provides an indication of the identified apnea.

Claims

1. An apnea analysis system comprising:

a photoplethysmographic (PPG) sub-system configured to be operatively connected to an individual and output a PPG signal from the individual;

a breath detection sub-system configured to be operatively connected to the individual and output a breath signal from the individual; and

an apnea analysis module in communication with the PPG sub-system and the breath detection sub-system, wherein the apnea analysis module analyzes the breath signal and a respiratory component of the PPG signal and, based on the analysis, identifies a presence of apnea, differentiates between obstructive apnea and central apnea, and provides an indication of the identified apnea.

2. The apnea analysis system of claim 1, wherein the respiratory component of the PPG comprises a baseline modulation, an amplitude modulation, or a frequency modulation of the PPG.

3. The apnea analysis system of claim 1, wherein the apnea analysis module identifies a presence of normal breathing when the breath signal and the respiratory component of the PPG include a modulating segment.

4. The apnea analysis system of claim 1, wherein the apnea analysis module identifies obstructive apnea when the respiratory component of the PPG includes a modulating segment and the breath signal includes an attenuated segment.

5. The apnea analysis system of claim 1, wherein the apnea analysis module identifies central apnea when the respiratory component of the PPG and the breath signal include an attenuated segment.

6. The apnea analysis system of claim 1, wherein the PPG sub-system includes a PPG sensor configured to be operatively connected to the individual, and wherein the apnea analysis module is configured to determine that the PPG sensor is disconnected from the individual when the respiratory component of the PPG signal includes an attenuated segment, and the breath signal includes a modulating segment.

7. The apnea analysis system of claim 1, wherein the PPG sub-system comprises processing equipment configured to determine an oxygen saturation value of the individual from the PPG signal.

8. The apnea analysis system of claim 7, wherein the breath detection sub-system comprises a breath-sampling interface configured to be connected to the individual, wherein the apnea analysis module is configured to determine that the breath-sampling interface is disconnected from the individual when the respiratory component of the PPG signal includes a modulating segment, the breath signal includes an attenuated segment, and the oxygen saturation value exceeds a threshold.

9. The apnea analysis system of claim 1, wherein the PPG sub-system comprises a pulse oximeter.

10. The apnea analysis system of claim 1, wherein the breath detection sub-system comprises one or more of a capnographic sub-system, a pressure detection sub-system, a temperature detection sub-system, a moisture sub-system, or an acoustic detection sub-system.

11. The apnea analysis system of claim 1, wherein the apnea analysis module is configured to output a confidence metric with respect to the respiratory component of the PPG signal based on detected modulations of a baseline, a cardiac pulse amplitude, or a cardiac pulse frequency.

12. A system for classifying an apnea, comprising:

a photoplethysmographic (PPG) sub-system configured to output a first signal indicative of a respiratory component of a PPG signal from a patient over a time period;

a breath detection sub-system configured to output a second signal indicative of a presence of breaths from the patient over the time period; and

an apnea analysis module configured to identify and classify an apnea based on the first and second signals.

13. The system of claim 12, wherein the respiratory component of the PPG signal comprises a baseline modulation of the PPG signal.

14. The system of claim 12, wherein the respiratory component of the PPG signal comprises an amplitude modulation of the PPG signal.

15. The system of claim 12, wherein the respiratory component of the PPG signal comprises a frequency modulation of the PPG signal.

16. An apnea analysis method comprising:

receiving a photoplethysmographic (PPG) signal indicative of a cardiac status of an individual;

receiving a breath signal indicative of a breathing status of the individual;

identifying a respiratory component of the PPG signal indicative of a respiration effort or a respiration rate;

comparing the breath signal and the respiratory component of the PPG;

identifying a presence of apnea, and differentiating between obstructive apnea and central apnea, based on the comparison.

17. The method of claim 16, further comprising outputting a confidence metric with respect to the respiratory component of the PPG signal based on detected modulations of a baseline, a cardiac pulse amplitude, or a cardiac pulse frequency.

18. The method of claim 16, further comprising determining an oxygen saturation value of the individual from the PPG signal.

19. A method for classifying an apnea, comprising:

receiving a breath signal and a respiratory rate or effort signal;

identifying a reduction in one of the breath signal or the respiratory rate or effort signal over a time period;

identifying a corresponding status of the other of the breath signal or the respiratory rate or effort signal over at least a portion of the time period; and

classifying a type of apnea based on the reduction in the one of the breath signal or the respiratory rate or effort signal and the corresponding status of the other of the breath signal or the respiratory rate or effort signal.

20. The method of claim 20, wherein identifying a reduction in one of the breath signal or the respiratory rate or effort signal comprises identifying a reduction in modulations present in the signal.