METHOD AND APPARATUS FOR ARTIFACTS MITIGATION WITH MULTIPLE WIRELESS SENSORS

• US 20110066381A1
• Filed: 01/08/2010
• Published: 03/17/2011
• Est. Priority Date: 09/11/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Baheti, Pawan K., Garudadri, Harinath, Majumdar, Somdeb
• Granted Patent: US 8,718,980 B2
• Time in Patent Office: Days
• US Class Current: 702/19
• 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 5/0024 for multiple sensor units attached to the patient, e.g. using a body or personal area network
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/721 using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured
• CPC Class Codes: A61B 5/7232 involving compression of the physiological signal, e.g. to extend the signal recording period

Abstract

Certain aspects of the present disclosure relate to a technique for mitigating artifacts of biophysical signals in a body area network. Information from multiple sensors (including motion information of the body) can be employed in mitigating the artifacts. The biophysical signals in the body area network can be compressively sensed.

Claims

1. A method for signal processing, comprising:

generating sampling instances according to a random seed;

sensing motion information;

compressively sensing a first set of samples of a signal during the sampling instances;

adjusting the sampling instances based on at least one of the sensed motion information or the sensed first set of samples; and

compressively sensing a second set of samples of the signal during the adjusted sampling instances.

2. The method of claim 1, further comprising:

transmitting at least one of the sensed motion information or the sensed second set of samples.

3. The method of claim 1, wherein the adjustment comprises at least one of:

updating an under-sampling ratio (USR) using at least one of the sensed motion information or the sensed first set of samples;

correcting a bias of the signal based on the motion information, wherein an offset of the bias to be corrected is due to motion of the apparatus represented with the motion information;

or

controlling a lighting intensity of one or more light-emitting diodes (LEDs) using at least one of the sensed motion information or the sensed first set of samples.

4. The method of claim 1, further comprising:

generating multiple packets comprising at least one of the sensed motion information, the sensed first set of samples, the sensed second set of samples, or the random seed; and

transmitting at least one of the multiple packets.

5. The method of claim 1, wherein the signal comprises at least one of:

a red photoplethysmograph (PPG) signal, an infrared PPG signal, or an electro-cardiogram (ECG) signal.

6. The method of claim 1, wherein the motion information is compressively sensed.

7. The method of claim 1, further comprising:

receiving feedback information,

wherein the feedback information comprises at least one of;

an update of an under-sampling ratio (USR), information about a lighting intensity of one or more light-emitting diodes (LEDs), or a correction of a bias of the signal.

8. The method of claim 7, wherein the adjustment utilizes at least one of:

the updated USR, the lighting intensity of the one or more LEDs, or the corrected bias.

9. An apparatus for signal processing, comprising:

a first circuit configured to generate sampling instances according to a random seed;

a sensor configured to sense motion information;

another sensor configured to compressively sense a first set of samples of a signal during the sampling instances; and

a second circuit configured to adjust the sampling instances based on at least one of the sensed motion information or the sensed first set of samples, wherein

the other sensor is also configured to compressively sense a second set of samples of the signal during the adjusted sampling instances.

10. The apparatus of claim 9, further comprising:

a transmitter configured to transmit at least one of the sensed motion information or the sensed second set of samples.

11. The apparatus of claim 9, wherein the second circuit is also configured to perform at least one of:

updating an under-sampling ratio (USR) using at least one of the sensed motion information or the sensed first set of samples;

correcting a bias of the signal based on the motion information, wherein an offset of the bias to be corrected is due to motion of the apparatus represented with the motion information;

or

controlling a lighting intensity of one or more light-emitting diodes (LEDs) using at least one of the sensed motion information or the sensed first set of samples.

12. The apparatus of claim 9, wherein

the first circuit is also configured to generate multiple packets comprising at least one of the sensed motion information, the sensed first set of samples, the sensed second set of samples, or the random seed, and the apparatus further comprising

a transmitter configured to transmit at least one of the multiple packets.

13. The apparatus of claim 9, wherein the signal comprises at least one of:

a red photoplethysmograph (PPG) signal, an infrared PPG signal, or an electro-cardiogram (ECG) signal.

14. The apparatus of claim 9, wherein the motion information is compressively sensed.

15. The apparatus of claim 9, further comprising:

a receiver configured to receive feedback information,

wherein the feedback information comprises at least one of;

an update of an under-sampling ratio (USR), information about a lighting intensity of one or more light-emitting diodes (LEDs), or a correction of a bias of the signal.

16. The apparatus of claim 15, wherein the second circuit configured to adjust the sampling instances utilizes at least one of:

the updated USR, the lighting intensity of the one or more LEDs, or the corrected bias.

17. An apparatus for signal processing, comprising:

means for generating sampling instances according to a random seed;

means for sensing motion information;

means for compressively sensing a first set of samples of a signal during the sampling instances;

means for adjusting the sampling instances based on at least one of the sensed motion information or the sensed first set of samples; and

means for compressively sensing a second set of samples of the signal during the adjusted sampling instances.

18. The apparatus of claim 17, further comprising:

means for transmitting at least one of the sensed motion information or the sensed second set of samples.

19. The apparatus of claim 17, wherein the means for adjusting comprises at least one of:

means for updating an under-sampling ratio (USR) using at least one of the sensed motion information or the sensed first set of samples;

means for correcting a bias of the signal based on the motion information, wherein an offset of the bias to be corrected is due to motion of the apparatus represented with the motion information;

or

means for controlling a lighting intensity of one or more light-emitting diodes (LEDs) using at least one of the sensed motion information or the sensed first set of samples.

20. The apparatus of claim 17, further comprising:

means for generating multiple packets comprising at least one of the sensed motion information, the sensed first set of samples, the sensed second set of samples, or the random seed; and

means for transmitting at least one of the multiple packets.

21. The apparatus of claim 17, wherein the signal comprises at least one of:

a red photoplethysmograph (PPG) signal, an infrared PPG signal, or an electro-cardiogram (ECG) signal.

22. The apparatus of claim 17, wherein the motion information is compressively sensed.

23. The apparatus of claim 17, further comprising:

means for receiving feedback information,

wherein the feedback information comprises at least one of;

an update of an under-sampling ratio (USR), information about a lighting intensity of one or more light-emitting diodes (LEDs), or a correction of a bias of the signal.

24. The apparatus of claim 23, wherein the means for adjusting utilizes at least one of:

the updated USR, the lighting intensity of the one or more LEDs, or the corrected bias.

25. A computer-program product for signal processing, comprising a computer-readable medium comprising instructions executable to:

generate sampling instances according to a random seed;

sense motion information;

compressively sense a first set of samples of a signal during the sampling instances;

adjust the sampling instances based on at least one of the sensed motion information or the sensed first set of samples; and

compressively sense a second set of samples of the signal during the adjusted sampling instances.

26. A sensing device, comprising:

a first circuit configured to generate sampling instances according to a random seed;

a sensor configured to sense motion information;

another sensor configured to compressively sense a first set of samples of a signal during the sampling instances;

a second circuit configured to adjust the sampling instances based on at least one of the sensed motion information or the sensed first set of samples, wherein

the other sensor is also configured to compressively sense a second set of samples of the signal during the adjusted sampling instances; and

a transmitter configured to transmit at least one of the sensed motion information or the sensed second set of samples.

27. A method for signal processing, comprising:

receiving motion information and samples of a signal;

generating a sparsity basis and a sensing matrix;

determining at least one sparse space coefficient by using the sensing matrix, the sparsity basis and the received samples;

modifying the at least one sparse space coefficient based on the motion information; and

determining one or more other signals related to the received samples by using the at least one modified sparse space coefficient.

28. The method of claim 27, further comprising:

generating, based on at least one of the determined one or more other signals or the motion information, feedback information for adjusting sensing at an apparatus of at least one of other samples of the signal or other motion information, the other samples and the other motion information to be received from the apparatus; and

transmitting the generated feedback information to the apparatus.

29. The method of claim 28, wherein the feedback information comprises at least one of:

an update of an under-sampling ratio (USR) information about a lighting intensity of light-emitting diodes (LEDs), or a correction of DC component of the signal.

30. The method of claim 27, wherein the signal comprises at least one of:

a red photoplethysmograph (PPG) signal, an infrared (IR) PPG signal, or an electro-cardiogram (ECG) signal.

31. The method of claim 30, wherein the determined one or more other signals comprise at least one of:

a DC component, a root mean square (RMS) component, or a waveform.

32. The method of claim 27, further comprising

modifying, based on the motion information, at least one of:

a determined level of oxygenation in blood, a determined heart rate, a red photoplethysmograph (PPG) signal, an infrared (IR) PPG signal, an electro-cardiogram (ECG) signal, or the one or more other signals;

wherein the one or more other signals comprise at least one of;

a DC component, a root mean square (RMS) component, or a waveform.

33. The method of claim 27, wherein the at least one sparse space coefficient is determined according to the orthogonal matching pursuit algorithm.

34. The method of claim 27, further comprising

providing, based on the determined one or more other signals, an indication of at least one of:

a heart rate, a level of blood oxygenation, a photoplethysmograph (PPG) signal, or an electro-cardiogram (ECG) signal.

35. The method of claim 27, wherein the modification comprises:

setting the at least one sparse space coefficient to zero.

36. The method of claim 27, further comprising:

receiving one or more packets comprising at least one of a corrupted version of the motion information or a corrupted version of the samples; and

reconstructing at least one of the motion information or the samples using the one or more packets.

37. The method of claim 27, wherein determining the at least one sparse space coefficient further comprises:

identifying the at least one sparse space coefficient based on a priori statistical information about noise sources.

38. An apparatus for signal processing, comprising:

a receiver configured to receive motion information and samples of a signal;

a first circuit configured to generate a sparsity basis and a sensing matrix;

a computer configured to determine at least one sparse space coefficient by using the sensing matrix, the sparsity basis and the received samples;

a second circuit configured to modify the at least one sparse space coefficient based on the motion information; and

an estimator configured to determine one or more other signals related to the received samples by using the at least one modified sparse space coefficient.

39. The apparatus of claim 38, further comprising:

a third circuit configured to generate, based on at least one of the determined one or more other signals or the motion information, feedback information for adjusting sensing at another apparatus of at least one of other samples of the signal or other motion information, the other samples and the other motion information to be received from the other apparatus; and

a transmitter configured to transmit the generated feedback information to the other apparatus.

40. The apparatus of claim 39, wherein the feedback information comprises at least one of:

an update of an under-sampling ratio (USR) information about a lighting intensity of light-emitting diodes (LEDs), or a correction of DC component of the signal.

41. The apparatus of claim 38, wherein the signal comprises at least one of:

a red photoplethysmograph (PPG) signal, an infrared (IR) PPG signal, or an electro-cardiogram (ECG) signal.

42. The apparatus of claim 41, wherein the determined one or more other signals comprise at least one of:

a DC component, a root mean square (RMS) component, or a waveform.

43. The apparatus of claim 38, further comprising

a third circuit configured to modify, based on the motion information, at least one of a determined level of oxygenation in blood, a determined heart rate, a red photoplethysmograph (PPG) signal, an infrared (IR) PPG signal, an electro-cardiogram (ECG) signal, or the one or more other signals;

wherein the one or more other signals comprise at least one of;

a DC component, a root mean square (RMS) component, or a waveform.

44. The apparatus of claim 38, wherein the at least one sparse space coefficient is determined according to the orthogonal matching pursuit algorithm.

45. The apparatus of claim 38, further comprising

a third circuit configured to provide, based on the determined one or more other signals, an indication of at least one of:

a heart rate, a level of blood oxygenation, a photoplethysmograph (PPG) signal, or an electro-cardiogram (ECG) signal.

46. The apparatus of claim 38, wherein the second circuit is also configured to set the at least one sparse space coefficient to zero.

47. The apparatus of claim 38, wherein

the receiver is also configured to receive one or more packets comprising at least one of a corrupted version of the motion information or a corrupted version of the samples, and the apparatus further comprising

a reconstructing circuit configured to reconstruct at least one of the motion information or the samples using the one or more packets.

48. The apparatus of claim 38, wherein the computer is also configured to identify the at least one sparse space coefficient based on a priori statistical information about noise sources.

49. An apparatus for signal processing, comprising:

means for receiving motion information and samples of a signal;

means for generating a sparsity basis and a sensing matrix;

means for determining at least one sparse space coefficient by using the sensing matrix, the sparsity basis and the received samples;

means for modifying the at least one sparse space coefficient based on the motion information; and

means for determining one or more other signals related to the received samples by using the at least one modified sparse space coefficient.

50. The apparatus of claim 49, further comprising:

means for generating, based on at least one of the determined one or more other signals or the motion information, feedback information for adjusting sensing at another apparatus of at least one of other samples of the signal or other motion information, the other samples and the other motion information to be received from the other apparatus; and

means for transmitting the generated feedback information to the other apparatus.

51. The apparatus of claim 50, wherein the feedback information comprises at least one of:

an update of an under-sampling ratio (USR) information about a lighting intensity of light-emitting diodes (LEDs), or a correction of DC component of the signal.

52. The apparatus of claim 49, wherein the signal comprises at least one of:

a red photoplethysmograph (PPG) signal, an infrared (IR) PPG signal, or an electro-cardiogram (ECG) signal.

53. The apparatus of claim 52, wherein the determined one or more other signals comprise at least one of:

a DC component, a root mean square (RMS) component, or a waveform.

54. The apparatus of claim 49, further comprising

means for modifying, based on the motion information, at least one of:

a determined level of oxygenation in blood, a determined heart rate, a red photoplethysmograph (PPG) signal, an infrared (IR) PPG signal, an electro-cardiogram (ECG) signal, or the one or more other signals;

wherein the one or more other signals comprise at least one of;

a DC component, a root mean square (RMS) component, or a waveform.

55. The apparatus of claim 49, wherein the at least one sparse space coefficient is determined according to the orthogonal matching pursuit algorithm.

56. The apparatus of claim 49, further comprising

means for providing, based on the determined one or more other signals, an indication of at least one of:

a heart rate, a level of blood oxygenation, a photoplethysmograph (PPG) signal, or an electro-cardiogram (ECG) signal.

57. The apparatus of claim 49, wherein the means for modifying comprises means for setting the at least one sparse space coefficient to zero.

58. The apparatus of claim 49, wherein

the means for receiving is further configured to receive one or more packets comprising at least one of a corrupted version of the motion information or a corrupted version of the samples, and the apparatus further comprising

means for reconstructing at least one of the motion information or the samples using the one or more packets.

59. The apparatus of claim 49, wherein the means for determining the at least one sparse space coefficient further comprises:

means for identifying the at least one sparse space coefficient based on a priori statistical information about noise sources.

60. A computer-program product for signal processing, comprising a computer-readable medium comprising instructions executable to:

receive motion information and samples of a signal;

generate a sparsity basis and a sensing matrix;

determine at least one sparse space coefficient by using the sensing matrix, the sparsity basis and the received samples;

modify the at least one sparse space coefficient based on the motion information;

determine one or more other signals related to the received samples by using the at least one modified sparse space coefficient.

61. A headset, comprising:

a receiver configured to receive motion information and samples of a signal;

a first circuit configured to generate a sparsity basis and a sensing matrix;

a computer configured to determine at least one sparse space coefficient by using the sensing matrix, the sparsity basis and the received samples;

a second circuit configured to modify the at least one sparse space coefficient based on the motion information;

an estimator configured to determine one or more other signals related to the received samples by using the at least one modified sparse space coefficient; and

a transducer configured to provide an audio output based on the determined one or more other signals.

62. A watch, comprising:

a receiver configured to receive motion information and samples of a signal;

a first circuit configured to generate a sparsity basis and a sensing matrix;

a computer configured to determine at least one sparse space coefficient by using the sensing matrix, the sparsity basis and the received samples;

a second circuit configured to modify the at least one sparse space coefficient based on the motion information;

an estimator configured to determine one or more other signals related to the received samples by using the at least one modified sparse space coefficient; and

a user interface configured to provide an indication based on the determined one or more other signals.

63. A monitoring device, comprising:

a connector;

a receiver configured to receive via the connector motion information and samples of a signal;

a first circuit configured to generate a sparsity basis and a sensing matrix;

a computer configured to determine at least one sparse space coefficient by using the sensing matrix, the sparsity basis and the received samples;

a second circuit configured to modify the at least one sparse space coefficient based on the motion information;

an estimator configured to determine one or more other signals related to the received samples by using the at least one modified sparse space coefficient; and

a user interface configured to provide an indication based on the determined one or more other signals.