Pulse meter, method for controlling pulse meter, wristwatch-type information device, control program, storage medium, blood vessel simulation sensor, and living organism information measurement device

• US 20040186387A1
• Filed: 03/05/2004
• Published: 09/23/2004
• Est. Priority Date: 03/19/2003
• Status: Abandoned Application

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Baba, Norimitsu, Zakoji, Makoto, Kawafune, Yutaka, Kosuda, Tsukasa, Aoshima, Ichiro
• Application Number:
  US10/793,419
• Publication Number:
  US 20040186387A1
• Time in Patent Office: Days
• US Class Current: 600/502
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/02 Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
• 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 5/681 Wristwatch-type devices
• 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 5/7257 using Fourier transforms

Abstract

The present invention realizes calculating a pulse rate accurately, even when a body movement component has no periodical characteristics, by surely removing the body movement component generated in a living organism from a pulse wave component. A pulse wave detecting section includes a pulse wave sensor and outputs a pulse wave detection signal to an MPU functioning as a body motion component removing section. A body motion sensor outputs a body motion detection signal corresponding to a body motion that affects the behavior of venous blood to the MPU. As a result, to the MPU removes the body motion component from the pulse wave detection signal based on the body motion detection signal. A pulse rate calculating section calculates the pulse rate based on the pulse wave detection signal from which the body motion component has been removed. The pulse rate is displayed on a liquid crystal display device.

Claims

1. A living organism information measurement device adapted to be attached to a human body to measure living organism information, comprising:

a pulse wave detecting section configured and arranged to output a pulse wave detection signal by using a pulse wave sensor;

a body motion component removing section configured and arranged to detect a body motion component resulting from venous blood movements of the human body that is contained in said pulse wave detection signal and remove said body motion component contained in said pulse wave detection signal; and

a living organism information measuring section configured and arranged to measure living organism information based on said pulse wave detection signal from which said body motion component has been removed.

2. A pulse meter adapted to be attached to a human body to measure a pulse of the human body, comprising:

a pulse wave detecting section configured and arranged to output a pulse wave detection signal by using a pulse wave sensor;

a body motion detecting section configured and arranged to detect accelerations corresponding to body motions that affect a venous blood behavior by using an acceleration sensor and output a body motion detection signal;

a body motion component removing section configured and arranged to remove a body motion component contained in said pulse wave detection signal based on said body motion detection signal; and

a pulse rate calculating section configured and arranged to calculate a pulse rate based on said pulse wave detection signal from which said body motion component has been removed.

3. The pulse meter as recited in claim 2, wherein

said acceleration sensor is a triaxial acceleration sensor that is configured and arranged to detect accelerations in directions along an X-axis, a Y-axis and a Z-axis, said X-axis being defined as an axis substantially parallel to an arm of a user, said Z-axis being defined as an axis that is perpendicular to said X-axis and a palm of the user, and said Y-axis being defined as an axis that is perpendicular to said X-axis and said Y-axis.

4. The pulse meter as recited in claim 2, wherein

said acceleration sensor is positioned in the vicinity of said pulse wave sensor.

5. The pulse meter as recited in claim 2, wherein

said acceleration sensor is substantially stacked on said pulse wave sensor.

6. The pulse meter as recited in claim 3, wherein

said body motion component removing section includes a body motion component generating section that is configured and arranged to generate said body motion component based on said X-axis acceleration component, said Y-axis acceleration component, and said Z-axis acceleration component.

7. The pulse meter as recited in claim 6, wherein

said body motion component generating section is configured and arranged to generate said body motion component based on said X-axis acceleration component and a biaxial integrated acceleration component obtained by integrating vectors corresponding to said Y-axis acceleration component and said Z-axis acceleration component.

8. The pulse meter as recited in claim 6, wherein

said body motion component generating section is configured and arranged to generate said body motion component based on a triaxial integrated acceleration component obtained by integrating vectors corresponding to said X-axis acceleration component, said Y-axis acceleration component and said Z-axis acceleration component.

9. The pulse meter as recited in claim 6, wherein

at least one of said X-axis acceleration component, said Y-axis acceleration component and said Z-axis acceleration component is weighted in said body motion component generating section.

10. The pulse meter as recited in claim 6, wherein

said body motion component removing section includes

a filter coefficient generating section configured and arranged to generate an adaptive filter coefficient based on said X-axis acceleration component, said Y-axis acceleration component and said Z-axis acceleration component, and

a removal processing section configured and arranged to remove said body motion component from said pulse wave detection signal based on said adaptive filter coefficient.

11. The pulse meter as recited in claim 6, wherein

said body motion component removing section is configured and arranged to remove a prescribed low frequency band component contained as the body motion component from said pulse wave detection signal by using a prescribed simulated low-frequency signal.

12. The pulse meter as recited in claim 10, wherein

said filter coefficient generating section is configured and arranged to generate an adaptive filter coefficient based on a prescribed simulated low-frequency component to remove a prescribed low frequency band component contained as the body motion component from said pulse wave detection signal by using said prescribed simulated low-frequency signal, and

said removal processing section is configured and arranged to remove the body motion component from said pulse wave detection signal based on said adaptive filter coefficient.

13. The pulse meter as recited in claim 2, comprising

a body motion information detecting section configured and arranged to detect a pitch of step or step counts from said body motion component contained in said pulse wave detection signal.

14. A method for measuring a pulse of a human body, comprising:

performing pulse wave detection signal outputting process for outputting a pulse wave detection signal detected by a pulse wave sensor attached on the human body;

performing acceleration detecting process for detecting accelerations corresponding to body motions that affect a venous blood behavior using an acceleration sensor attached on the human body, said acceleration sensor being a triaxial acceleration sensor configured and arranged to detect accelerations in directions along an X-axis, a Y-axis and a Z-axis, said X-axis being defined as an axis substantially parallel to an arm of a user, said Z-axis being defined as an axis that is perpendicular to said X-axis and a palm of the user, and said Y-axis is defined as an axis that is perpendicular to said X-axis and said Y-axis;

performing body motion detection signal outputting process for outputting a body motion detection signal corresponding to said accelerations detected in said acceleration detecting process;

performing body motion component generating process for generating a body motion component based on an X-axis acceleration component in a direction along said X-axis, a Y-axis acceleration component in a direction along said Y-axis, and a Z-axis acceleration component in a direction along said Z-axis;

performing body motion component removing process for removing said body motion component from said pulse wave detection signal; and

performing pulse rate calculating process for calculating a pulse rate based on said pulse wave detection signal from which said body motion component has been removed.

15. The method as recited in claim 14, wherein

said body motion component generating process includes generating said body motion component based on said X-axis acceleration component and a biaxial integrated acceleration component obtained by integrating vectors corresponding to said Y-axis acceleration component and said Z-axis acceleration component.

16. The method as recited in claim 14, wherein

said body motion component generating process includes generating said body motion component based on a triaxial integrated acceleration component obtained by integrating vectors corresponding to said X-axis acceleration component, said Y-axis acceleration component and said Z-axis acceleration component.

17. The method as recited in claim 14, wherein

said body motion component removing process includes removing a prescribed low frequency band component contained as said body motion component from said pulse wave detection signal by using a prescribed simulated low-frequency signal.

18. A wristwatch type information device configured to be placed on an arm of a user, comprising:

a pulse wave detecting section configured and arranged to output a pulse wave detection signal by using a pulse wave sensor;

a body motion component generating section configured and arranged to generate a body motion component based on an X-axis acceleration component in a direction along an X-axis, a Y-axis acceleration component in a direction along a Y-axis and a Z-axis acceleration component in a direction along a Z-axis detected by a triaxial acceleration sensor, said X-axis being defined as an axis substantially parallel to the arm of the user, said Z-axis being defined as an axis that is perpendicular to said X-axis and a palm of the user, and said Y-axis being defined as an axis that is perpendicular to said X-axis and said Y-axis;

a body motion component removing section configured and arranged to remove said body motion component from said pulse wave detection signal;

a pulse rate calculating section configured and arranged to calculate a pulse rate based on said pulse wave detection signal after said body motion component is removed; and

a display section configured and arranged to display said pulse rate.

19. A control program for controlling, by a computer, a pulse meter adapted to be attached to a human body to measure a pulse of the human body and having a pulse wave detecting section configured and arranged to output a pulse wave detection signal by using a pulse wave sensor and a body motion detecting section configured and arranged to detect accelerations corresponding to body motions that affect a venous blood behavior by using an acceleration sensor and output a body motion detection signal, said control program comprising instructions for performing:

removing a body motion component contained in said pulse wave detection signal based on said body motion detection signal; and

calculating a pulse rate based on said pulse wave detection signal after said body motion component is removed.

20. A pulse meter adapted to be attached to a human body to measure a pulse, comprising:

a pulse wave detecting section configured and arranged to output a pulse wave detection signal by using a pulse wave sensor;

a body motion component removing section configured and arranged to remove a body motion component contained in said pulse wave detection signal based on a relative positional difference in a vertical direction between a position of the heart of the human body and a position where said pulse meter is attached; and

a pulse rate calculating section configured and arranged to calculate a pulse rate based on said pulse wave detection signal after said body motion component is removed.

21. The pulse meter as recited in claim 20, wherein

said body motion component removing section includes a body motion detecting section configured and arranged to detect a body motion component expressed as a function of said relative positional difference and output a body motion detection signal.

22. The pulse meter as recited in claim 21, wherein

said body motion detecting section includes a pressure sensor configured and arranged to detect said body motion component.

23. The pulse meter as recited in claim 22, wherein

said pressure sensor is positioned in the vicinity of said pulse wave sensor.

24. The pulse meter as recited in claim 22, wherein

said pressure sensor is substantially stacked on said pulse wave sensor.

25. The pulse meter as recited in claim 24, wherein

said body motion component removing section includes

a difference detecting section configured and arranged to detect said relative positional difference, and

a body motion component generating section configured and arranged to generate said body motion component based on said relative positional difference.

26. The pulse meter as recited in claim 25, wherein

said difference detecting section includes an angle sensor configured and arranged to detect, as said relative positional difference, an angle difference of an actual position of said pulse meter with respect to a reference angle of said pulse meter.

27. The pulse meter as recited in claim 26, wherein

said angle sensor is positioned in the vicinity of said pulse wave sensor.

28. The pulse meter as recited in claim 26, wherein

said angle sensor is substantially stacked on said pulse wave sensor.

29. The pulse meter as recited in claim 26, wherein

said angle sensor is configured and arranged to detect said angle difference based on a stationary acceleration.

30. The pulse meter as recited in claim 26, wherein

said angle sensor is configured and arranged to have a rotary spindle and detect said angle difference based on a rotational state of said rotary spindle.

31. The pulse meter as recited in claim 25, wherein

said difference detecting section includes

an angle compensating section configured and arranged to compensate said angle difference according to said prescribed body motion component when said angle difference indicates said position where said pulse meter is attached is higher than said position of the heart of the human body by an amount greater than a threshold value.

32. The pulse meter as recited in claim 20, wherein

said body motion component removing section includes

a removal processing section configured and arranged to subtract a body motion detection signal corresponding to said body motion component based on said relative positional difference from said pulse wave detection signal.

33. The pulse meter as recited in claim 20, wherein

said body motion removing section includes

a first frequency analyzing section configured and arranged to execute a frequency analysis of a body motion component detection signal corresponding to said body motion component based on said relative positional difference and generate first frequency analysis data,

a second frequency analyzing section configured and arranged to execute a frequency analysis of said pulse wave detection signal and generate second frequency analysis data, and

a removal processing section configured and arranged to subtract said first frequency analysis data from said second frequency analysis data.

34. The pulse meter as recited in claim 20, wherein

said body motion component removing section includes

a filter coefficient generating section configured and arranged to generate an adaptive filter coefficient based on a body motion component detection signal corresponding to said body motion component based on said relative positional difference, and

a removal processing section configured and arranged to subtract said body motion component detection signal applied with said adaptive filter coefficient from said pulse wave detection signal.

35. The pulse meter as recited in claim 20, comprising

a body motion information detecting section configured and arranged to detect a pitch of step or step counts from said body motion component contained in said pulse wave detection signal based on said relative positional difference.

36. A method for measuring a pulse of a human body, comprising:

performing pulse wave detecting process for outputting a pulse wave signal using by a pulse wave sensor attached to the human body;

performing body motion component removing process for removing a body motion component contained in said pulse wave detection signal based on a relative positional difference in a vertical direction between a position of the heart of the human body and a position where said pulse meter is attached; and

performing pulse rate calculating process for calculating a pulse rate based on said pulse wave detection signal after said body motion component is removed.

37. A wristwatch type information device, comprising:

a pulse wave detecting section configured and arranged to be placed on a pulse wave detection position of the human body to output a pulse wave detection signal by using a pulse wave sensor; and

a main body configured and arranged to be placed on a wrist of the human body, said main body including

a body motion component removing section configured and arranged to remove a body motion component contained in said pulse wave detection signal based on a relative positional difference in a vertical direction between a position of the heart of the human body and a position where said pulse wave detecting section is attached,

a pulse rate calculating section configured and arranged to calculate a pulse rate based on said pulse wave detection signal after said body motion component is removed, and

a display section configured and arranged to display said pulse rate.

38. A control program for controlling, by a computer, a pulse meter adapted to be attached to a human body to measure a pulse and having a pulse wave detecting section configured and arranged to output a pulse wave signal by using a pulse wave sensor, said control program comprising instructions for performing:

removing a body motion component contained in said pulse wave detection signal based on a relative positional difference in a vertical direction between a position of the heart of the human body and a position where said pulse meter is attached; and

calculating a pulse rate based on said pulse wave detection signal after said body motion component is removed.

39. A computer readable medium configured and arranged to store a control program for controlling, by a computer, a pulse meter adapted to be attached to a human body to measure a pulse of the human body and having a pulse wave detecting section configured and arranged to output a pulse wave detection signal by using a pulse wave sensor and a body motion detecting section configured and arranged to detect accelerations corresponding to body motions that affect a venous blood behavior by using an acceleration sensor and output a body motion detection signal, said control program comprising instructions for performing:

removing a body motion component contained in said pulse wave detection signal based on said body motion detection signal; and

calculating a pulse rate based on said pulse wave detection signal after said body motion component is removed.

40. A blood vessel simulation sensor adapted to be attached to a human body to simulate a behavior of venous blood of the human body, comprising:

a casing;

simulation blood disposed inside said casing and having a viscosity substantially equal to a viscosity of the venous blood; and

a behavior detection sensor configured and arranged to detect a behavior of said simulation blood.

41. The blood vessel simulation sensor as recited in claim 40, wherein

said casing is made of a rigid material.

42. The blood vessel simulation sensor as recited in claim 41, wherein

said casing includes a transparent resin tube with each end of said tube being closed, and

said behavior detection sensor is a photodetector configured and arranged to measure a change in a surface of said simulation blood.

43. The blood vessel simulation sensor as recited in claim 41, wherein

said casing includes a resin tube with each end of said tube being closed, and

said behavior detection sensor is a pressure sensor positioned at one end of said casing to detect a change in a pressure as said simulation blood moves inside said casing.

44. The blood vessel simulation sensor as recited in claim 40, wherein

said casing is made of a resilient material.

45. The blood vessel simulation sensor as recited in claim 44, wherein

said casing includes a tube with each end of said tube being closed, and

said behavior detection sensor is a pressure sensor positioned at one end of said casing to detect a change in a pressure as said simulation blood moves inside said casing.

46. The blood vessel simulation sensor as recited in claim 44, wherein

said casing includes a tube with each end of said tube being closed, and

said behavior detection sensor is a pressure sensor positioned on a side of said casing to detect a change in a pressure as said simulation blood moves inside said casing.

47. A blood vessel simulation sensor adapted to be attached to a human body to simulate a behavior of venous blood of the human body, comprising:

an acceleration sensor having a sensitivity axis in a direction substantially toward a peripheral direction of the human body to output a signal corresponding to a movement of the venous blood toward said peripheral direction.

48. A pulse meter adapted to be attached to a human body to measure a pulse of the human body, comprising:

a pulse wave detecting section configured and arranged to output a pulse wave detection signal by using a pulse wave sensor;

a blood vessel simulation sensor configured and arranged to be attached to a human body and simulate a behavior of venous blood of the human body, including

a casing,

simulation blood disposed inside said casing and having a viscosity substantially equal to a viscosity of the venous blood, and

a behavior detection sensor configured and arranged to detect a behavior of said simulation blood;

a body motion component removing section configured and arranged to remove a simulation body motion component corresponding to an output signal from said behavior detection sensor from said pulse wave detection signal; and

a pulse rate calculating section configured and arranged to calculate a pulse rate based on said pulse wave detection signal after said simulation body motion component is removed.

49. The pulse meter as recited in claim 48, wherein

said blood vessel simulation sensor is positioned in the vicinity of said pulse wave sensor.

50. The pulse meter as recited in claim 48, wherein

said blood vessel simulation sensor is substantially stacked on said pulse wave sensor in a direction that is spaced away from the human body.

51. The pulse meter as recited in claim 48, wherein

said body motion component removing section includes

a removal processing section configured and arranged to subtract a body motion component detection signal corresponding to the output signal from said behavior detection sensor from said pulse wave detection signal.

52. The pulse meter as recited in claim 48, wherein

said body motion component removing section includes

a first frequency analyzing section configured and arranged to execute a frequency analysis of a body motion component detection signal corresponding to said output signal from said behavior detection sensor and generate first frequency analysis data,

a second frequency analyzing section configured and arranged to execute a frequency analysis of said pulse wave detection signal and generate second frequency analysis data, and

a removal processing section configured and arranged to execute a subtraction processing of said first frequency analysis data with respect to said second frequency analysis data.

53. The pulse meter as recited in claim 48, wherein

said body motion component removing section includes

a filter coefficient generating section configured and arranged to generate an adaptive filter coefficient based on a body motion detection signal corresponding to the output signal from said behavior detection sensor, and

a removal processing section configured and arranged to subtract said body motion detection signal to which said adaptive filter coefficient has been applied from said pulse wave detection signal.

54. A living organism information measurement device, comprising:

a blood vessel simulation sensor configured and arranged to be attached to a human body and simulate a behavior of venous blood of the human body, including

a casing,

simulation blood disposed inside said casing and having a viscosity substantially equal to a viscosity of the blood in vein, and

a behavior detection sensor configured and arranged to detect a behavior of said simulation blood; and

a living organism information detecting section configured and arranged to detect a pitch of step or step counts corresponding to body motions of the human body based on an output signal of said blood vessel simulation sensor.

55. A computer readable medium configured and arranged to store a control program for controlling, by a computer, a pulse meter adapted to be attached to a human body to measure a pulse and having a pulse wave detecting section configured and arranged to output a pulse wave signal by using a pulse wave sensor, said control program comprising instructions for performing:

removing a body motion component contained in said pulse wave detection signal based on a relative positional difference in a vertical direction between a position of the heart of the human body and a position where said pulse meter is attached; and

calculating a pulse rate based on said pulse wave detection signal after said body motion component is removed.