Tissue Elasticity Measurement Device and Measurement Method

Patent metadata

Field	Value
Publication number	US-2020245974-A1
Application number	US-201816490397-A
Country	US
Kind code	A1
Filing date	Mar 7, 2018
Priority date	Mar 7, 2017
Publication date	Aug 6, 2020
Grant date	—

Abstract

There is provided a tissue elasticity measurement device 100 and a measurement method that allow for quantitative evaluation of biological changes related to tissue elasticity such as liver fibrosis. The tissue elasticity measurement device 100 has a supersonic wave measuring instrument 100 a that measures a pulse waveform corresponding to a blood flow velocity by a pulse wave Doppler method, and an information processor 100 b that calculates a deviation index value corresponding to a coefficient of variation from a pulse waveform obtained by the supersonic wave measuring instrument 100 a.

First claim

1 . A tissue elasticity measurement device comprising:
a supersonic wave measuring instrument that measures a pulse waveform corresponding to a blood flow velocity by a pulse wave Doppler method; and an information processor that calculates a deviation index value corresponding to a coefficient of variation from a pulse waveform obtained by the supersonic wave measuring instrument.

2 . The tissue elasticity measurement device according to claim 1 , wherein the information processor has a waveform processor that determines at least one of: an absolute maximum flow velocity, a maximum value, a minimum value, and a mean value at each time phase of a pulse waveform, and calculates a coefficient of variation from at least one of the absolute maximum flow velocity, the maximum value, the minimum value, and the mean value.

3 . The tissue elasticity measurement device according to claim 2 , wherein the waveform processor extracts an envelope so as to conform to a standard three-phase pulse waveform having a retrograde first waveform part with an ascending peak of a flow velocity, an antegrade second waveform part with a descending peak of a flow velocity, and an antegrade third waveform part with a descending peak of a flow velocity during a heartbeat period, and calculates a coefficient of variation therefrom.

4 . The tissue elasticity measurement device according to claim 3 , wherein an envelope is extracted at a high-velocity side of the absolute value of the first waveform part in the case where there exists the first waveform part, an envelope is extracted at a high-velocity side of the absolute value of the second waveform part in the case where there exists the second waveform part, and an envelope is extracted at a high-velocity side of the absolute value of the third waveform part in the case where there exists the third waveform part.

5 . The tissue elasticity measurement device according to claim 1 , wherein a CV value standing for the coefficient of variation, is given by the following expression:

CV


=



1
n



Σ

i
=
1

n



(

V
i

-

V

m

_

peak

)

2



V

m

_

peak

where, n is the number of samples of a pulse waveform, V i is a blood flow velocity, and V m_peak is a mean value of the blood flow velocity.

6 . The tissue elasticity measurement device according to claim 1 , wherein the information processor measures the deviation index value from a vein waveform corresponding to a plurality of heartbeat periods.

7 . The tissue elasticity measurement device according to claim 1 , wherein the supersonic wave measuring instrument uses fast Fourier transform to generate, from a Doppler component, a measurement value of a flow velocity for each time resolution.

8 . The tissue elasticity measurement device according to claim 1 , wherein the supersonic wave measuring instrument measures a vein waveform of liver.

9 . A measurement method for obtaining a pulse waveform corresponding to a blood flow velocity by pulse wave Doppler method, the method comprising calculating a deviation index value corresponding to a coefficient of variation from a pulse waveform obtained by measurement.

Assignees

• Univ Tokyo

Inventors

• Soroida Yoko
• Nakatsuka Takuma
• Sato Masaya
• Nakagawa Hayato
• Ikeda Hitoshi
• Koike Kazuhiko
• Yatomi Yutaka

Classifications

• A61B8/5223

  for extracting a diagnostic or physiological parameter from medical diagnostic data (for algorithms to analyse biomedical images G06T7/0012) · CPC title

• A61B8/5207

  involving processing of raw data to produce diagnostic data, e.g. for generating an image · CPC title

• A61B8/488 Primary

  involving Doppler signals · CPC title

• A61B8/485 Primary

  involving measuring strain or elastic properties · CPC title

• A61B8/085

  for locating body or organic structures, e.g. tumours, calculi, blood vessels, nodules · CPC title