MOTION/ACTIVITY, HEART-RATE AND RESPIRATION FROM A SINGLE CHEST-WORN SENSOR, CIRCUITS, DEVICES, PROCESSES AND SYSTEMS

• US 20110066041A1
• Filed: 08/24/2010
• Published: 03/17/2011
• Est. Priority Date: 09/15/2009
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Cole, Edwin Randolph, Ravindran, Sourabh, Pandia, Keya R.
• Application Number:
  US12/861,882
• Publication Number:
  US 20110066041A1
• Time in Patent Office: Days
• US Class Current: 600/484
• CPC Class Codes: A61B 2505/07 Home care
• CPC Class Codes: A61B 2560/0475 Special features of memory means, e.g. removable memory cards
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 5/029 Measuring or recording blood output from the heart, e.g. minute volume A61B8/065 takes precedence
• CPC Class Codes: A61B 5/1102 Ballistocardiography
• CPC Class Codes: A61B 5/113 occurring during breathing
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence
• 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 7/00 Instruments for auscultation
• CPC Class Codes: A61B 7/008 Detecting noise of gastric tract, e.g. caused by voiding

Abstract

A respiration monitoring device includes an accelerometer (210) for application to the chest, whereby acceleration is possible due to both non-respiratory body motion and respiration, and an electronic circuit (DSP) responsive to an acceleration signal from the accelerometer and operable to separate from the acceleration signal a heart signal, a respiration signal, and a substantially non-respiration body motion signal. Other devices, sensor articles, electronic circuit units, and processes are also disclosed.

Claims

1. A respiration monitoring device comprising:

an accelerometer for application to the chest, whereby acceleration is possible due to both non-respiratory body motion and respiration; and

an electronic circuit responsive to an acceleration signal from said accelerometer and operable to separate from the acceleration signal a heart signal, a respiration signal, and a substantially non-respiration body motion signal.

2. The respiration monitoring device claimed in claim 1 wherein said electronic circuit includes a smoothing filter operable to derive the heart signal to represent heart pulses as a residue of the smoothing filter.

3. The respiration monitoring device claimed in claim 1 wherein said electronic circuit is operable to derive respiration rate based on the respiration signal.

4. The respiration monitoring device claimed in claim 1 wherein said electronic circuit includes an electronic processor operable to filter in a manner to separate from the acceleration signal a heart signal and a slow wander signal and further operable to derive a respiration signal from the heart signal, and to subtract the respiration signal from the slow wander signal to produce the substantially non-respiration body motion signal.

5. The respiration monitoring device claimed in claim 4 wherein said electronic circuit includes a nonvolatile memory holding instructions and filter coefficients to direct operations of said electronic processor as aforesaid.

6. The respiration monitoring device claimed in claim 1 wherein said electronic circuit includes an electronic processor operable to perform an interpolation augmenting and based on the respiration signal for representing the respiration responsive to said accelerometer.

7. The respiration monitoring device claimed in claim 1 further comprising an output circuit coupled to said electronic circuit and operable to transmit signals representing heart, respiration, and non-respiration body motion information.

8. The respiration monitoring device claimed in claim 7 wherein said output circuit includes a modem is selected from the group consisting of:

1) Bluetooth,

     2) Zigbee.

9. The respiration monitoring device claimed in claim 7 wherein said output circuit includes a modem selected from the group consisting of:

1) cellular,

     2) Wi-Fi,

     3) WiMax.

10. The respiration monitoring device claimed in claim 7 wherein said output circuit includes a modem selected from the group consisting of:

1) digital subscriber line (DSL),

     2) cable,

     3) Ethernet.

11. The respiration monitoring device claimed in claim 1 wherein said electronic circuit includes a sampling circuit with an analog to digital converter to provide the acceleration signal in digital form based on a signal from said accelerometer.

12. The respiration monitoring device claimed in claim 1 wherein said electronic circuit is further operable to provide a respiration signal responsive to said accelerometer with a period greater than about ⅓

second.

13. The respiration monitoring device claimed in claim 1 wherein said electronic circuit is further operable independent of the heart signal to separate a first motion signal component responsive to said accelerometer above approximately two (2) Hertz from a second motion signal component responsive to said accelerometer below approximately two (2) Hertz.

14. The respiration monitoring device claimed in claim 13 wherein the motion signal component below approximately two (2) Hertz is used as a respiration signal and the motion signal component above approximately two (2) Hertz is used to represent other body motion.

15. The respiration monitoring device claimed in claim 1 wherein said accelerometer has a sensor oriented to have an axis of acceleration sensitivity perpendicular to the chest for application thereto, the sensor coupled to said electronic circuit.

16. The respiration monitoring device claimed in claim 1 wherein said electronic circuit is operable to extract at least three vitals including respiration, activity, and heart-rate from a single signal from said accelerometer.

17. The respiration monitoring device claimed in claim 1 further comprising a disposable adhesive patch physically associated to the accelerometer and said electronic circuit.

18. The respiration monitoring device claimed in claim 17 further comprising a support member for said adhesive patch, said accelerometer and said electronic circuit.

19. The respiration monitoring device claimed in claim 1 further comprising a respiration display circuit coupled to said electronic circuit.

20. A process for physiological monitoring comprising:

receiving an acceleration signal;

filtering the acceleration signal to separate a heart signal from a slow wander signal;

deriving a respiration signal from the heart signal; and

subtracting a signal based on the respiration signal from the slow wander signal to produce a substantially non-respiration body motion signal.

21. The process for physiological monitoring claimed in claim 20 further comprising fall monitoring for an unusually high-magnitude peak in the non-respiration body motion signal.

22. The process for physiological monitoring claimed in claim 20 further comprising generating a motion-based signal from the non-respiration body motion signal indicative that the motion level is sufficiently high to affect reliability of at least one of the heart signal and the respiration signal.

23. The process for physiological monitoring claimed in claim 20 further comprising operating a transmitting circuit to send information about heart, the respiration, and non-respiration body motion to another location.

24. A physiological sensor article comprising:

an accelerometer for application to the chest, whereby acceleration is possible due to both non-respiratory body motion and respiration;

an electronic circuit responsive to said accelerometer and operable to derive a first signal representing heart pulses having amplitude modulation and further to generate a second signal that varies responsive to the amplitude modulation; and

a signal interface operable to transmit respiration information based on the second signal.

25. The physiological sensor article claimed in claim 24 wherein said electronic circuit is operable to derive the first signal representing heart pulses by removal of motion-dependent wander, and to repeatedly measure successive S1 peak amplitudes electronically beat-by-beat in the first signal to electronically generate the second signal based on the successive S1 heart pulse peak amplitudes responsive to said accelerometer.

26. The physiological sensor article claimed in claim 24 wherein said electronic circuit is operable to augment the second signal by interpolation to generate a more-nearly continuous respiration signal.

27. An electronic process comprising removing motion-dependent wander from an accelerometer sensor to obtain a heart sound signal having successive peak amplitudes, deriving electronically beat-by-beat a signal representing heart sound peak amplitudes, and transmitting respiration information based on the heart sound peak amplitudes.

28. An electronic circuit unit for use with a signal input, the electronic circuit unit comprising:

a signal interface to receive and convert the signal input to an electronic form for further processing;

an electronic processing circuit fed by said signal interface and including a filter operable to separate a heart signal from a slow wander signal, to derive a respiration signal from the heart signal, and to subtract the respiration signal from the slow wander signal to produce a substantially non-respiration body motion signal; and

a modem coupled to transmit at least some information generated by said electronic processing circuit.

29. The electronic circuit unit claimed in claim 28 wherein said electronic processing circuit is further operable to process the respiration signal to obtain parameters for respiration including values on the respiration signal and differences and trends.

30. The electronic circuit unit claimed in claim 28 wherein said electronic processing circuit is further operable to process one or more of the respiration signal, non-respiration body motion signal and heart signal to detect coughing.

31. The electronic circuit unit claimed in claim 28 wherein said electronic processing circuit is further operable to derive walking gait from the non-respiration body motion signal.

32. The electronic circuit unit claimed in claim 28 wherein said electronic processing circuit is further operable to peak-detect an unusually high-magnitude peak in the non-respiration body motion signal.

33. The electronic circuit unit claimed in claim 32, for use by a user who might physically fall, wherein said electronic processing circuit is further operable to generate an output signal representing possibility of a fall occurrence as a function of the peak-detect operation.

34. The electronic circuit unit claimed in claim 28 wherein said electronic processing circuit is further operable to derive a motion-based signal from the non-respiration body motion signal indicative that the motion level is sufficiently high to affect reliability of at least one of the heart signal and the respiration signal.

35. The electronic circuit unit claimed in claim 34 wherein said electronic processing circuit is further operable from the motion-based signal to gate at least one of the heart signal and the respiration signal.

36. The electronic circuit unit claimed in claim 28 wherein said electronic processing circuit is further operable to peak-detect a peak in the non-respiration body motion signal that is substantially higher in magnitude than neighbor peaks in a predetermined window of time.

37. The electronic circuit unit claimed in claim 28 wherein said electronic processing circuit is further operable to process the non-respiration body motion signal to generate an output representing level of general bodily activity.

38. The electronic circuit unit claimed in claim 28 wherein said electronic processing circuit is further operable to successively estimate a varying physical location from the same signal input of said signal interface.