Study on simultaneous measurement of blood vessel thickness and blood flow velocity using multi-wavelength laser speckle

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04413
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21030:Measurement engineering-related
• Research Institution: Meiji University
• Principal Investigator: Sawano Hiroshi 明治大学, 理工学部, 専任准教授 (40514295)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 血管計測 / 血管厚さ / 血流 / レーザースペックル / 多波長計測 / 赤外レーザ

Outline of Final Research Achievements

In this study, a method to separate blood vessel thickness and blood flow velocity information from laser speckle information of multiple wavelengths was proposed, for the purpose of realizing simultaneous measurement of blood vessel thickness and blood flow velocity.
A blood vessel thickness measurement principle evaluation experimental device with a flow path that imitated a blood vessel was constructed, and a measurement experiment using two-wavelength laser speckles of 420 nm and 780 nm was conducted. From the experimental results, it was cleared that the measurement method proposed enables simultaneous measurement of blood vessel thickness and blood flow velocity in principle.
Furthermore, similar experiments were performed using two-wavelength infrared laser speckles of 780 nm and 850 nm, and it was shown that simultaneous measurement of blood vessel thickness and blood flow velocity is possible even from two-wavelength infrared laser speckles.

Free Research Field

機械工学

Academic Significance and Societal Importance of the Research Achievements

血流は大切な生体情報であり，非侵襲で高精度な血流の計測は重要な役割を持っている．出力が小さく，透過性を持つ赤外レーザを照射することにより，人体に負荷をかけることなく血流の速度を計測することが可能である．血管の厚さを計測することが可能になれば，血管の閉塞などの情報を得ることができるが，レーザが血管まで到達すると，血管厚さと血流速さの両方の情報がスペックルに反映されるため，レーザースペックルによる血管厚さの計測は困難であった．本研究は2波長レーザを用いることで血管厚さと血流速さの両方の情報を同時に得ることを可能にするものであり，日常的な健康管理機器への応用が期待できる．