METHOD AND SYSTEM FOR MONITORING SLEEP

• US 20110124979A1
• Filed: 08/11/2008
• Published: 05/26/2011
• Est. Priority Date: 08/21/2007
• Status: Active Grant

• Current Assignee: ResMed Sensor Technologies Limited (ResMed Incorporated)
• Original Assignee: University College Dublin
• Inventors: Mcdarby, Gareth, Chua, Eric C.-P., Heneghan, Conor
• Granted Patent: US 10,154,790 B2
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/346 Analysis of electrocardiograms
• CPC Class Codes: A61B 5/4812 Detecting sleep stages or cycles
• CPC Class Codes: A61B 5/4818 Sleep apnoea

Abstract

A method of monitoring sleep comprises simultaneously recording a person'"'"'s electrocardiogram (ECG) and photoplethysmogram (PPG), deriving a plurality of parameters from the recorded data, and providing an output indicative of a sleep characteristic based upon an analysis of the parameters. The ECG and PPG may be recorded using an apparatus which is a combination of a Holter monitor and a pulse oximeter, which is wearable in ambulatory manner.

Claims

1-12. -12. (canceled)

13. A method of monitoring sleep stages and level of sleepiness, comprising simultaneously recording a person'"'"'s electrocardiogram (ECG) and photoplethysmogram (PPG), deriving a plurality of parameters from the recorded data, and providing an output indicative of sleep stage or level of sleepiness based upon an analysis of the parameters.

14. The method of claim 13, wherein the ECG and PPG are recorded using a recording apparatus wearable in ambulatory manner.

15. The method of claim 14, wherein the recording apparatus comprises a combination of a Holter monitor and a pulse oximeter.

16. The method of claim 13, wherein the parameters include at least one of RR interval, pulse amplitude, pulse arrival time and respiratory rate.

17. The method of claim 16, wherein the parameters are analysed by extracting from the parameters a plurality of features suitable for classifying the sleep characteristic of interest, and feeding a subset of the features into a quantitative classifier to obtain an estimate of the characteristic.

18. The method of claim 17, wherein the features include at least one of PPG spectral spread, PPG pulse amplitude, respiratory rate variability, detrended fluctuation analysis, time and frequency analysis and multi-scale entropy.

19. The method of claim 13, wherein the sleep stages comprise wakefulness, rapid-eye-movement sleep, and non-rapid-eye-movement sleep.

20. The method of claim 13, comprising assigning sleep stages and levels of sleepiness to specific epochs of time of greater than 10 seconds in duration.

21. The method of claim 20, comprising classifying a single epoch according to the classification of surrounding epochs.

22. The method of claim 17, further comprising estimating the output of a psychomotor vigilance test using the output of the quantitative classifier.

23. A system for monitoring sleep stages and level of sleepiness, comprising an apparatus for simultaneously recording a subject'"'"'s electrocardiogram (ECG) and photoplethysmogram (PPG), and a data processor for deriving a plurality of parameters from the recorded data and providing an output indicative of sleep stage or level of sleepiness based upon an analysis of the parameters.

24. The system of claim 23, wherein the recording apparatus is wearable in ambulatory manner.

25. The system of claim 24, wherein the recording apparatus comprises a combination of a Holter monitor and a pulse oximeter.