Systems and methods for monitoring cough

• US 7,727,161 B2
• Filed: 04/24/2007
• Issued: 06/01/2010
• Est. Priority Date: 04/10/2003
• Status: Active Grant

• Current Assignee: Adidas AG
• Original Assignee: VivoMetrics, Inc.
• Inventors: Derchak, P. Alexander, Coyle, Michael, Myers, Lance Jonathan
• Primary Examiner(s): Mallari; Patricia C
• Assistant Examiner(s): Toth; Karen E
• Application Number:
  US11/739,527
• Publication Number:
  US 20070276278A1
• Time in Patent Office: 1,134 Days
• Field of Search: 600529-543
• US Class Current: 600/538
• CPC Class Codes: A61B 5/0823 Detecting or evaluating cough events
• CPC Class Codes: A61B 5/113 occurring during breathing
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/398 Electrooculography [EOG], e.g. detecting nystagmus; Electroretinography [ERG]
• CPC Class Codes: A61B 5/4812 Detecting sleep stages or cycles
• CPC Class Codes: A61B 5/6805 Vests

Abstract

The present invention provides systems and methods for monitoring subjects, especially during sleep. Respiratory and sound data are recorded and coughs arousal are recognized as joint events in both of these signals having selected characteristics. Further, cough-arousal events during sleep are recognized when a likely cough occurs in association with a recognized EEG arousal. Cough arousal events are combined into a cough arousal index that reflects disease severity and sleep disruption due to cough. The methods of this invention are computer-implemented and can be provided as a program product including a computer readable medium. Measurements and indices provided by this invention can be used to monitor and to treat respiratory diseases.

Claims

1. A computer-implemented method for monitoring cough in a subject comprising:

providing a monitoring system that is adapted to monitor at least one physiological parameter associated with the subject, said monitoring system including means for monitoring chest wall movement that is adapted to provide chest wall movement data representing movement of the rib cage and abdomen, an audio sensor that is adapted to detect sound emanating from the subject and provide sound data representing said emanating sound, and a motion detector that is adapted to detect motion and change of posture of the subject and provide accelerometer data representative of said subject motion and posture;

monitoring the subject with said monitoring system, whereby first chest wall movement data and first sound data is provided;

determining tidal volume data from said first chest wall movement data;

processing said first chest wall movement data and said tidal volume data using a processor in order to recognize respiratory events when a measure of peak power in said first chest wall movement data exceeds a threshold level;

processing said first sound data with said processor in order to recognize sound events when a sound envelope exceeds a threshold level;

processing concurrent respiratory and sound events with said processor to identify patterns characteristic of a cough;

determining a measure of pitch of concurrent sound events; and

identifying a cough if the characteristic patterns are present and if said determined pitch measure of said concurrent sound event indicates the absence of speech sounds.

2. The method of claim 1, wherein said first sound data is obtained from a sensor that is configured to be in contact with, or in close proximity to, said subject'"'"'s throat.

3. The method of claim 1, wherein said sound envelope threshold comprises a selected multiple of calibrated background noise.

4. The method of claim 1, wherein said pitch comprises mel frequency wrapping.

5. The method of claim 1, wherein said pitch measure indicates that said overlapping sound event does not include speech sounds if a maximum pitch is less than a cough-speech threshold.

6. The method of claim 5, wherein said cough-speech threshold comprises a mel-frequency threshold of approximately 1.5 or greater.

7. The method of claim 1, wherein said pitch measure indicates that said overlapping sound event does not include speech sounds if signal power at pitches below a cough-speech threshold increases.

8. The method of claim 1, wherein said pitch measure indicates that said overlapping sound event does not include speech sounds if the average of recent maximum pitches is less than a cough-speech threshold level.

9. The method of claim 1, further comprising, monitoring motion and posture of the subject with said motion detector, whereby first accelerometer data is provided, and for each cough event, processing said first accelerometer data in order to recognize motion and/or change of posture of the subject;

retaining said selected cough event if no subject motion and/or change of posture is recognized during said cough; and

otherwise discarding said cough event if subject motion and/or change of posture is recognized during said cough.

10. A computer-implemented method for monitoring cough in a subject comprising:

monitoring respiratory movement data derived from the rib cage, the abdomen or both and sound data with a monitoring device responsive to said subject;

processing and filtering respiratory movement data and tidal volume data that is derived from said respiratory movement data using a processor in order to recognize respiratory events when a measure of peak power in said filtered data exceeds a threshold level;

processing monitored sound data with said processor in order to recognize sound events when a sound envelope exceeds a threshold level;

processing said tidal volume data during occurrences of concurrent respiratory and sound events with said processor to identify patterns characteristic of a cough;

filtering said tidal volume data in dependence on characteristics of said concurrent sound events;

identifying a cough during an occurrence of concurrent respiratory and sound events if said characteristic patterns are present in said tidal volume data.

11. The computer implemented method of claim 10, wherein the tidal volume data is filtered into a low frequency band if the duration of the concurrent sound event is greater than a threshold, and into a high frequency band if the duration of the concurrent sound event data is less than a threshold.

12. The method of claim 10, wherein abdomen movement data and tidal volume data are filtered prior to recognizing respiratory events.

13. The method of claim 10, further comprising:

determining a measure of pitch of said sound events during occurrences of concurrent respiratory and sound events; and

identifying a cough if said characteristic patterns are present in said tidal volume data and if a determined pitch measure of said sound event indicates the absence of speech sounds.