Patent ID: 8864672
Filing Date: 2014-10-21
Classification: A61B

Abstract:
1. A blood rheology measurement device comprising: a first measurement unit that measures a flow rate of blood flowing through an artery inside of a living body from outside a surface of the living body and that outputs a time varying blood flow rate waveform corresponding to the measured blood flow rate; a second measurement unit that measures, from outside the surface of the living body, a diameter of the artery and a pulsatile displacement value corresponding to a displacement of the artery in a diameter direction thereof due to expansion and contraction of the artery resulting from a pulsatile motion of the heart, and that outputs the measured artery diameter and a time varying blood vessel pulsatile displacement waveform corresponding to the pulsatile displacement value; and a rheology calculation processing unit that calculates a blood rheology in the artery on the basis of the time varying blood flow rate waveform, the time varying blood vessel pulsatile displacement waveform, and the measured artery diameter output from the first and second measurement units; wherein the second measurement unit comprises: a transmitting section that transmits an ultrasonic burst signal to the artery, and a receiving section that receives a plurality of ultrasonic burst signals reflected by inner and outer walls of the artery as a result of the transmitted ultrasonic burst signal, the transmitted and reflected ultrasonic burst signals forming burst signal waveforms that propagate between the surface of the living body and the artery in the living body with delay time differences therebetween; and a blood vessel information calculation processing unit that calculates a delay time difference between one of the received ultrasonic burst signals and another one of the received ultrasonic burst signals to output the measured artery diameter and the time varying blood vessel pulsatile displacement waveform, the time varying blood vessel pulsatile displacement waveform being detected on the basis of a change amount of the artery diameter that is proportional to the calculated delay time difference between the one of the received ultrasonic burst signals and the another one of the received ultrasonic burst signals; and wherein the rheology calculation processing unit comprises: a heartbeat frequency calculation processing unit that calculates a heartbeat frequency on the basis of the time varying blood flow rate waveform output from the first measurement unit and the time varying blood vessel pulsatile displacement waveform output from the second measurement unit; a parameter calculation processing unit that calculates a phase difference or an amplitude ratio between the time varying blood flow rate waveform and the time varying blood vessel pulsatile displacement waveform on the basis of the respective waveforms; and a rheology index calculation processing unit that calculates a kinematic viscosity of the blood by use of one of the calculated phase difference and amplitude ratio, the measured artery diameter, and the heartbeat frequency.