Method of detecting pulse wave, method of detecting artery position, and pulse wave detecting apparatus

• US 6,334,850 B1
• Filed: 08/19/1999
• Issued: 01/01/2002
• Est. Priority Date: 11/19/1997
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Amano, Kazuhiko, Ishiyama, Hitoshi, Uebaba, Kazuo
• Primary Examiner(s): O'Connor, Cary
• Assistant Examiner(s): Natnithithadha, Navin
• Application Number:
  US09/341,248
• Time in Patent Office: 866 Days
• Field of Search: 600/500, 600/501, 600/502, 600/503
• US Class Current: 600/500
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/6822 Neck
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/726 using Wavelet transforms

Abstract

An optical type pulse wave detection section 1 detects the pulse waveform MH above the skin while moving in the circumferential direction of the arm, when a manual position change mechanism 2 is operated. Capillary vessels and arterioles surrounding a radial artery 24 are formed inside the skin, and pulsation of the capillary vessels and arterioles are opposite in polarity. When a polarity detection section 3 outputs a polarity detection signal KS showing the polarity of the pulse waveform MH, the polarity is displayed on a display 4. Accordingly, a subject can position the pulse wave detection section 1 above the arterioles surrounding the artery by operating the manual position change mechanism 2 while observing the display 4, allowing the pulse waveform MH to be detected with an optimal SN ratio. In addition, the pulse waveform of the arterioles can be detected by specifying the position of the artery without causing a constrictive feeling to the subject.

Claims

1. A method of detecting a pulse wave using a pulse wave detection means which detects a pulse waveform from blood flowing through blood vessels around an artery, said method comprising steps of:

detecting the pulse waveform by said pulse wave detection means at a plurality of positions;

sensing a polarity of the pulse waveform detected by said pulse wave detection means; and

detecting said pulse waveform detected in a position range from a position where said polarity is inverted to a position where said polarity is returned to an original polarity as the pulse waveform from the blood vessels around the artery.

2. A method of detecting a pulse wave, comprising steps of:

detecting a pulse waveform by a pulse wave detection means which detects the pulse waveform from blood flowing through blood vessels around an artery at a plurality of detection positions;

sensing a polarity of the pulse waveform detected by said pulse wave detection means; and

detecting the pulse wave of said artery positioned approximately at a center of the blood vessels around said artery in a position range from a position where said polarity is inverted to a position where said polarity is returned to an original polarity.

3. A method of detecting a position of an artery using a pulse wave detection means which detects a pulse waveform from blood flowing through blood vessels around said artery, said method comprising steps of:

detecting the pulse waveform by said pulse wave detection means at a plurality of positions;

sensing a polarity of the pulse waveform detected by said pulse wave detection means; and

detecting the location of said artery in a position range from a position where said polarity is inverted or is in the process of being inverted to a position where said polarity is returned to an original polarity.

4. A pulse wave detecting apparatus, comprising:

a pulse wave detection means for detecting a pulse waveform of blood vessels around an artery from a detection part of a living body at a plurality of positions; and

a pulse wave waveform display means for displaying said pulse waveform.

21. The pulse wave detecting apparatus according to claim 4, wherein said pulse wave detection means is an optical type pulse wave detection means for detecting a pulse wave of blood vessels around an artery based on a light absorption property of blood flowing through the blood vessels around the artery.

22. The pulse wave detecting apparatus according to claim 21, wherein said pulse wave detection means is set so that detection wavelength exists in a wavelength range from 300 nm to 700 nm.

5. A pulse wave detecting apparatus, comprising:

a pulse wave detection means for detecting a pulse waveform of blood vessels around an artery from a detection part of a living body at a plurality of positions;

a polarity detection means for detecting a polarity of the pulse waveform which is output from said pulse wave detection means; and

an announcement means for announcing a detection result of said polarity detection means.

6. The pulse wave detecting apparatus according to claim 5, further comprising a position change means for changing a relative position between said pulse wave detection means and said detection part.

7. The pulse wave detecting apparatus according to claim 6, wherein said position change means changes the relative position between said pulse wave detection means and said detection part so as to exist within a position range from a position where the polarity detected by said polarity detection means is inverted to a position where the polarity is returned to the original polarity.

8. The pulse wave detecting apparatus according to claim 5, further comprising a body movement elimination means for eliminating a component due to body movement from the pulse waveform detected by said pulse wave detection means to create a body movement eliminated pulse waveform,

wherein said polarity detection means detects a polarity based on said body movement eliminated pulse waveform.

13. The pulse wave detecting apparatus according to claim 8, wherein said body movement elimination means comprises:

a body movement detection section for detecting said body movement of the living body;

a first frequency analysis section for performing a frequency analysis of a body movement waveform detected by said body movement detection section;

a second frequency analysis section for performing a frequency analysis of a pulse waveform detected by said pulse wave detection means; and

a body movement elimination section for creating said body movement eliminated pulse waveform by comparing frequency analysis results analyzed by said first frequency analysis section and said second frequency analysis section.

14. The pulse wave detecting apparatus according to claim 13, wherein said first frequency analysis section and said second frequency analysis section perform frequency analysis using FFT.

15. The pulse wave detecting apparatus according to claim 5, further comprising a body movement elimination means for eliminating a component due to body movement from the pulse waveform detected by said pulse wave detection means to create a body movement eliminated pulse waveform,

wherein said body movement elimination means comprises:

a body movement detection section for detecting said body movement of the living body;

a first frequency analysis section for performing a frequency analysis of a body movement waveform detected by said body movement detection section;

a second frequency analysis section for performing a frequency analysis of pulse waveform detected by said pulse wave detection means; and

a body movement elimination section for creating said body movement eliminated pule waveform by comparing frequency analysis results analyzed by said first frequency analysis section and said second frequency analysis section,

wherein said first frequency analysis section and said second frequency analysis section perform frequency analysis using FFT, and

wherein said position change means moves while stopping for a discontinuance time which is at least a minimum period of time to perform the FFT.

16. The pulse wave detecting apparatus according to claim 13, wherein said first frequency analysis section and said second frequency analysis section perform frequency analysis using wavelet transformation.

17. The pulse wave detecting apparatus according to claim 5, further comprising a body movement elimination means for eliminating a component due to body movement from the pulse waveform detected by said pulse wave detection means to create a body movement eliminated pulse waveform,

wherein said body movement elimination means comprises:

a body movement detection section for detecting said body movement of the living body;

a first frequency analysis section for performing a frequency analysis of a body movement waveform detected by said body movement detection section;

a second frequency analysis section for performing a frequency analysis of a pulse waveform detected by said pulse wave detection means; and

a body movement elimination section for creating said body movement eliminated pulse waveform by comparing frequency analysis results analyzed by said first frequency analysis section and said second frequency analysis section,

wherein said first frequency analysis section and said second frequency analysis section perform frequency analysis using wavelet transformation, and

wherein said position change means moves while stopping for a discontinuance time which is at least a minimum period of time to perform the wavelet transformation.

18. The pulse wave detecting apparatus according to claim 8, wherein said body movement elimination means comprises:

a frequency analysis section for performing frequency analysis of the pulse waveform from said pulse wave detection means; and

a body movement separation section creating said body movement eliminated pulse waveform based on a frequency component from which a low frequency component is eliminated in a frequency analysis result analyzed by said frequency analysis section.

19. The pulse wave detecting apparatus according to claim 18, wherein said body movement separation section determines the maximum frequency of said low frequency component based on a basic frequency of the pulse waveform detected by said pulse wave detection means.

20. The pulse wave detecting apparatus according to claim 18, wherein said frequency analysis section performs frequency analysis using FFT or wavelet transformation.

9. A pulse wave detecting apparatus, comprising:

a pulse wave detection means for detecting a pulse waveform of blood vessels around an artery from a detection part of a living body at a plurality of positions;

a polarity detection means for detecting a polarity of the pulse waveform which is output from said pulse wave detection means;

an amplitude detection means for detecting an amplitude of the pulse waveform which is output from said pulse wave detection means; and

an announcement means for announcing a detected result of said polarity detection means and a detected result of said amplitude detection means.

12. The pulse wave detecting apparatus according to claim 9, comprising a body movement elimination means for eliminating a component due to a body movement from the pulse waveform detected by said pulse wave detection means to create a body movement eliminated pulse waveform,

wherein said polarity detection means detects a polarity based on said body movement eliminated pulse waveform, and

wherein said amplitude detection means detects an amplitude based on said body movement eliminated pulse waveform.

10. A pulse wave detecting apparatus, comprising:

a pulse wave detection means for detecting a pulse waveform of blood vessels around an artery from a detection part of a living body at a plurality of positions;

a polarity detection means for detecting a polarity of the pulse waveform which is output from said pulse wave detection means; and

a position change means for changing the relative position between said pulse wave detection means and said detection part approximately to a center position in a position range from a position where the polarity detected by said polarity detection means is inverted to a position where the polarity is returned to the original polarity.

23. The pulse wave detecting apparatus according to any one of claims 6 to 8, 10 and 11, further comprising an artery pulse wave detection means for detecting a pulse wave of an artery positioned approximately at a center of blood vessels around said artery, and

wherein said artery pulse wave detection means is provided substantially at the same position as said pulse wave detection means and said relative position between said artery pulse wave detection means and said detection part is changed by said position change means.

11. A pulse wave detecting apparatus, comprising:

a pulse wave detection means for detecting a pulse waveform of blood vessels around an artery from a detection part of a living body at a plurality of positions;

a polarity detection means for detecting a polarity of the pulse waveform which is output from said pulse wave detection means;

an amplitude detection means for detecting an amplitude of the pulse waveform which is output from said pulse wave detection means; and

a position change means for changing the relative position between said pulse wave detection means and said detection part so that the relative position resides in a position range from a position where the polarity detected by said polarity detection means is inverted to a position where the polarity is returned to an original polarity and the amplitude detected by said amplitude detection means is made substantially maximized.