Vessel pulse wave measurement system conducting vessel pulse wave measurement by obtaining pulsation waveform of blood vessel

• US 8,483,805 B2
• Filed: 07/31/2012
• Issued: 07/09/2013
• Est. Priority Date: 01/24/2011
• Status: Active Grant

• Current Assignee: Act Medical Service Co., Ltd.
• Original Assignee: Act Medical Service Co., Ltd.
• Inventors: Chiba, Shintaro, Takenoshita, Seiichi, Hata, Yutaka, Wiedemann, Tokuko Saito, Annoh, Hiromichi, Yagi, Asako, Takahashi, Shinichi, Handa, Fukuto, Yajima, Toshikuni
• Primary Examiner(s): KISH, JAMES M
• Application Number:
  US13/562,655
• Publication Number:
  US 20120289839A1
• Time in Patent Office: 343 Days
• Field of Search: 600/407, 600473-480
• US Class Current: 600/473
• CPC Class Codes: A61B 5/0082 adapted for particular medical purposes
• CPC Class Codes: A61B 5/02108 from analysis of pulse wave characteristics
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• CPC Class Codes: A61B 5/02225 using the oscillometric method
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/4809 Sleep detection, i.e. determining whether a subject is asleep or not
• CPC Class Codes: A61B 5/4812 Detecting sleep stages or cycles
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/6824 Arm or wrist
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 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: G01L 9/0007 using photoelectric means G01L9/0076 takes precedence

Abstract

A vessel pulse wave measurement system performs vessel pulse wave measurement using an optical probe circuit provided with an optical probe including a light emitting element and a light receiving element, a drive circuit, and a detection circuit. A measurement device directly and synchronously feeds back an electrical signal from the optical probe to the drive circuit as a drive signal to generate a self-oscillation signal from the detection circuit, and measures the self-oscillation signal as a vessel pulse wave signal. A controller controls an operating point of at least one of the detection circuit and the drive circuit such that the self-oscillation signal substantially reaches a maximum level thereof.

Claims

1. A vessel pulse wave measurement system that performs vessel pulse wave measurement using an optical probe circuit, the optical probe circuit comprising:

an optical probe configured to include a light emitting element that radiates light to a blood vessel through a skin, and a light receiving element that receives, through the skin, reflected light from the blood vessel or transmitted light through the blood vessel;

a drive circuit that drives the light emitting element based on an inputted drive signal; and

a detection circuit that converts the light received by the light receiving element into an electrical signal and outputs the electrical signal,

wherein the vessel pulse wave measurement system comprises;

a measurement device configured to directly and synchronously feed back the electrical signal to the drive circuit as the drive signal, generate a self-oscillation signal from the detection circuit, and measure the self-oscillation signal as a vessel pulse wave signal; and

a controller configured to control an operating point of at least one of the detection circuit and the drive circuit such that the self-oscillation signal substantially reaches a maximum level thereof;

wherein the measurement device further includes a pressure sheet sensor provided between the optical probe circuit and a pressing portion provided on the optical probe circuit,

wherein the measurement device further includes a calibration part, and

wherein, when the vessel pulse wave signal is measured and a stress is applied to the optical probe circuit on the blood vessel by pressure applied to the pressing portion by a pressure actuator or by pressure applied to the pressing portion by a human and then the vessel pulse wave signal is not measured any more, the calibration part stores a voltage value of the vessel pulse wave signal obtained immediately before the vessel pulse wave signal is not measured, as a maximum blood pressure value voltage,

the calibration part stores a detected pressure value of the pressure sheet sensor as a maximum blood pressure value,

then, when the vessel pulse wave signal is measured by reducing the pressure, the calibration part stores a voltage value of the vessel pulse wave signal obtained immediately after the vessel pulse wave signal is measured, as a minimum blood pressure value voltage,

the calibration part stores a detected pressure value of the pressure sheet sensor as a minimum blood pressure value, and

the calibration part creates a conversion equation representing conversion from a blood pressure value voltage to a blood pressure value, based on the stored maximum blood pressure value voltage and maximum blood pressure value corresponding to the stored maximum blood pressure value voltage, and the stored minimum blood pressure value voltage and minimum blood pressure value corresponding to the stored minimum blood pressure value voltage, thereby performing calibration to convert a blood pressure value voltage of the vessel pulse wave signal to a blood pressure value, using the conversion equation.

2. A vessel pulse wave measurement system comprising a measurement device for measuring a vessel pulse wave signal by performing vessel pulse wave measurement, using an optical probe circuit, the optical probe circuit comprising:

an optical probe configured to include a light emitting element that radiates light to a blood vessel through a skin, and a light receiving element that receives, through the skin, reflected light from the blood vessel or transmitted light through the blood vessel;

a drive circuit that drives the light emitting element based on a drive signal to be inputted; and

a detection circuit that converts the light received by the light receiving element to an electrical signal and outputs the electrical signal,

wherein the measurement device further includes a pressure sheet sensor provided between the optical probe circuit and a pressing portion provided on the optical probe circuit,

wherein the measurement device further includes a calibration part, and

wherein, when the vessel pulse wave signal is measured and a stress is applied to the optical probe circuit on the blood vessel by pressure applied to the pressing portion by a pressure actuator or by pressure applied to the pressing portion by a human and then the vessel pulse wave signal is not measured any more, the calibration part stores a voltage value of the vessel pulse wave signal obtained immediately before the vessel pulse wave signal is not measured, as a maximum blood pressure value voltage,

the calibration part stores a detected pressure value of the pressure sheet sensor as a maximum blood pressure value,

then, when the vessel pulse wave signal is measured by reducing the pressure, the calibration part stores a voltage value of the vessel pulse wave signal obtained immediately after the vessel pulse wave signal is measured, as a minimum blood pressure value voltage,

the calibration part stores a detected pressure value of the pressure sheet sensor as a minimum blood pressure value, and

the calibration part creates a conversion equation representing conversion from a blood pressure value voltage to a blood pressure value, based on the stored maximum blood pressure value voltage and maximum blood pressure value corresponding to the stored maximum blood pressure value voltage, and the stored minimum blood pressure value voltage and minimum blood pressure value corresponding to the stored minimum blood pressure value voltage, thereby performing calibration to convert a blood pressure value voltage of the vessel pulse wave signal to a blood pressure value, using the conversion equation.