HEART MONITORING SYSTEM

• US 20160220152A1
• Filed: 09/10/2014
• Published: 08/04/2016
• Est. Priority Date: 09/13/2013
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited, Precordior Oy
• Original Assignee: Murata Manufacturing Co Limited, Turun yliopisto
• Inventors: MERIHEIN, Ulf, JUPPO, Marika, PNL, Mikko, GRNHOLM, Markus, KOIVISTO, Tero, SAIRANEN, Kati
• Granted Patent: US 10,178,964 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 5/1102 Ballistocardiography
• CPC Class Codes: A61B 5/1107 Measuring contraction of parts of the body, e.g. organ, muscle apparatus for measuring work or force in general G01L
• CPC Class Codes: A61B 5/1121 Determining geometric values, e.g. centre of rotation or angular range of movement
• CPC Class Codes: A61B 5/113 occurring during breathing
• CPC Class Codes: A61B 5/361 Detecting fibrillation
• CPC Class Codes: A61B 5/6823 Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• 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 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: G01C 19/5783 Mountings or housings not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719

Abstract

A device that includes a sensor of angular motion configured to obtain an angular ballistograph signal indicative of rotational movement of a chest of a subject. Signal processing means are configured to generate from this angular ballistocardiograph signal measured values of an output parameter, which is indicative of cardiac operation of the subject.

Claims

1. A system, characterized by including comprising:

a gyroscope configured to obtain on a chest of a subject and using Coriolis effect an angular ballistocardiograph signal indicative of rotational recoil movement on the chest of the subject in response to cardiovascular rotation within the chest of the subject; and

a signal processor configured to generate from the angular ballistocardiograph signal measured values of an output parameter indicative of cardiac operation of the subject.

2. The system of claim 1, further comprising:

a sensor unit comprising the sensor of angular motion; and

a control unit coupled to the sensor unit to receive the angular ballistocardiograph signal.

3. The system of claim 2, wherein

the sensor unit is configured to be attached to the exterior of the chest of the subject, and wherein

the control unit is communicatively coupled to the sensor unit to receive the angular ballistocardiograph signal.

4. The system of claim 1, wherein

the sensor of angular motion is configured to sense rotational movement in a sense direction that is parallel to an axis of rotation, and wherein

the sense direction of the sensor unit is configured to be aligned to a symmetry plane of a body of the subject.

5. The system of claim 4, wherein the subject is a human and the symmetry plane is the sagittal plane of the human subject.

6. The system of claim 2, wherein the system comprises a mobile computing device.

7. The system of claim 2, wherein the system includes a remote node, communicatively coupled to the control unit.

8. The system of claim 1, wherein the signal processor is configured to generate from the angular ballistocardiograph signal a measured value representing radial orientation of the heart, angular velocity of the heart, or angular acceleration of the heart during the cardiac operation of the subject.

9. The system of claim 1, wherein the signal processor is configured to generate from the angular ballistocardiograph signal a measured value representing temporary stroke volume of the heart of the subject.

10. The system of claim 9, wherein

the angular ballistocardiograph signal is sequential,

the signal processor is configured to determine an amplitude of a sequence of the angular ballistocardiograph signal, and wherein

the signal processor is configured to use the amplitude to generate a measured value representing temporary stroke volume during the sequence of the angular ballistocardiograph signal.

11. The system of claim 1, wherein the signal processor is configured to generate from the angular ballistocardiograph signal a measured value representing beat-to-beat time or heart rate of a heart of the subject.

12. The system of claim 1, wherein the signal processor is configured to generate from the angular ballistocardiograph signal a measured value representing aortic closing or aortic opening of a heart of the subject.

13. The system of claim 1, wherein the signal processor is configured to generate from the angular ballistocardiograph signal a measured value representing another vital operation of the subject.

14. The system of claim 13, wherein the vital operation is respiration.

15. The system of claim 2, wherein the control unit is configured to store angular ballistocardiograph signals of a subject or measured values generated from the angular ballistocardiograph signals of the subject into a local or remote database.

16. The system of claim 15, wherein the control unit is configured to compare new measured values to a selected piece of stored information, and create an alarm if a deviation of new values from the stored information exceeds a predefined threshold.

17. The system of claim 1, wherein the signal processor is configured to

determine amplitude variation of the angular ballistocardiograph signal;

and

generate measured values of an output parameter from the determined amplitude variation of the angular ballistocardiograph signal.

18. The system of claim 17, wherein the signal processor is configured to determine the amplitude variation from wave patterns repeating on a heart-beat rate on the angular ballistocardiograph signal so that the amplitude variation includes two or more increases of the amplitude and two or more decreases of the amplitude.

19. The system of claim 18, wherein the signal processor is configured to determine the amplitude variation from aortic opening (AO) wave patterns repeating on a heart-beat rate on the angular ballistocardiograph signal.

20. The system of claim 1, wherein the signal processor is configured to

extract from a signal indicative of electromagnetic phenomena related to cardiac activity a first wave pattern repeating on a heart-beat rate;

extract from the angular ballistocardiograph signal a second wave pattern repeating on the heart-beat rate;

form timing data, a value of the timing data being indicative of a time period from a reference point of the first wave pattern belonging to one heart-beat period to a reference point of the second wave pattern belonging to the same heart-beat period; and

use the timing data to generate measured values of an output parameter.

21. The system of claim 20, wherein the signal processor is configured to

determine correlation between the timing data and pacing data indicative of the heart-beat rate;

and

use the correlation to generate measured values of an output parameter.

22. The system of claim 20, wherein the signal processor is configured to

determine stochastic variation in the timing value between successive heart-beat periods;

and

use the stochastic variation to generate measured values of an output parameter.

23. The system of claim 17, wherein the signal processor is configured to use the output parameter to indicate abnormal cardiac operation of the subject.

24. The system of claim 23, wherein the abnormal cardiac operation results from atrial extrasystole or atrial fibrillation.

25. The system of claim 1, wherein the sensor unit is configured to be positioned on a pectoral part of the upper torso of the subject.

26. The system of claim 1, wherein the sensor unit is configured to be positioned on a backside part of the upper torso of the subject.

27. The system of claim 1, wherein the sensor unit is configured to obtain an angular ballistocardiograph signal with a microelectromechanical gyroscope.

28. A method, comprising:

obtaining with a gyroscope on a chest of a subject, and using Coriolis effect, an angular ballistocardiograph signal indicative of rotational recoil movement of the chest of the subject in response to cardiovascular rotation within the chest; and

generating from the angular ballistocardiograph signal measured values of an output parameter indicative of cardiac operation of the subject.

29. The method of claim 28, including:

attaching a sensor unit comprising the sensor of angular motion to the exterior of the chest of the subject; and

forwarding the angular ballistocardiograph signal to a control unit communicatively coupled to the sensor unit.

30. The method of claim 28, including:

sensing rotational movement in a sense direction that is parallel to an axis of rotation; and

aligning the sense direction to a symmetry plane of a body of the subject.

31. The method of claim 30, wherein the subject is a human and the symmetry plane is the sagittal plane of the human subject.

32. The method of claim 29, including forwarding the measured values to a remote node, said remote node being communicatively coupled to the control unit.

33. The method of claim 28, further comprising generating, from the angular ballistocardiograph signal a measured value representing radial orientation of a heart of the subject, angular velocity of the heart, or angular acceleration of the heart during the cardiac operation of the subject.

34. The method of claim 28, further comprising generating, from the angular ballistocardiograph signal a measured value representing temporary stroke volume of a heart of the subject.

35. The method of claim 45, characterized in wherein the angular ballistocardiograph signal is sequential, and the method comprises determining an amplitude of a sequence of the angular ballistocardiograph signal, and

using use the amplitude to generate a measured value representing temporary stroke volume during the sequence of the angular ballistocardiograph signal.

36. The method of claim 28, further comprising generating, from the angular ballistocardiograph signal, a measured value representing beat-to-beat time or heart rate of a heart of the subject.

37. The method of claim 28, further comprising generating, from the angular ballistocardiograph signal, a measured value representing aortic closing or aortic opening of a heart of the subject.

38. The method of claim 28, further comprising generating, from the angular ballistocardiograph signal, a measured value representing another vital operation of the subject.

39. The method of claim 38, wherein the vital operation is respiration.

40. The method of claim 28, further comprising storing angular ballistocardiograph signals of a subject or measured values generated from the angular ballistocardiograph signals of the subject in a local or remote database.

41. The method of claim 40, further comprising comparing new measured values to a selected piece of stored information, and creating an alarm if the deviation of new values from the stored information exceeds a predefined threshold.

42. The method of claim 28, further comprising

determining amplitude variation of the angular ballistocardiograph signal;

generating measured values of an output parameter from the amplitude variation of the angular ballistocardiograph signal.

43. The method of claim 42, further comprising determining the amplitude variation from wave patterns repeating on the heart-beat rate on the angular ballistocardiograph signal so that the amplitude variation includes two or more increases of the amplitude and two or more decreases of the amplitude.

44. The method of claim 43, further comprising determining the amplitude variation from aortic opening (AO) wave patterns repeating on a heart-beat rate on the angular ballistocardiograph signal.

45. The method of claim 28, further comprising:

extracting from a signal indicative of electromagnetic phenomena related to cardiac activity a first wave pattern repeating on a heart-beat rate;

extracting from the angular ballistocardiograph signal a second wave pattern repeating on the heart-beat rate;

forming timing data, a timing value of the timing data being indicative of a time period from a reference point of the first wave pattern belonging to one heart-beat period to a reference point of the second wave pattern belonging to the same heart-beat period; and

using the timing data to generate measured values of an output parameter.

46. The method of claim 45, further comprising:

determining a correlation between the timing data and pacing data indicative of a heart-beat rate;

using the correlation to generate measured values of an output parameter.

47. The method of claim 46, further comprising

determining stochastic variation in the timing value between successive heart-beat periods;

and

using the stochastic variation to generate measured values of an output parameter.

48. The method of claim 42, further comprising using the output parameter to indicate abnormal cardiac operation of the subject.

49. The method of claim 48, wherein the abnormal cardiac operation results from atrial extrasystole or atrial fibrillation.

50. The method of claim 29, further comprising positioning the sensor unit on a pectoral part of an upper torso of the subject.

51. The system of claim 29, further comprising positioning the sensor unit on a backside part of the upper torso of the subject.

52. The system of claim 29, further comprising obtaining the angular ballistocardiograph signal with a microelectromechanical gyroscope.

53. A computer program product embodied on a non-transitory computer-readable medium, said computer-readable medium encoding instructions for executing the method of claim 28 in a cardiac monitoring system, when run on a computer.

54. A system, comprising:

gyroscope means for obtaining on a chest of a subject, and using Coriolis effect, an angular ballistocardiograph signal indicative of rotational recoil movement on the chest of the subject in response to cardiovascular rotation within the chest of the subject; and

signal processing means for generating, from the angular ballistocardiograph signal, measured values of an output parameter indicative of cardiac operation of the subject.