Laser doppler blood flow measuring method and device

Abstract

[Subject] To provide laser Doppler blood flow measuring method and device which achieve multi-dimensional measurement efficiently at a high degree of accuracy over a wide range with a simple optical system and device. [Solving Means] Laser light from a semiconductor laseris split and formed into sheet lights Ls using a cylindrical lens, and the sheet lights Ls are crossed with each other at a predetermined position. A lens systemconfigured to form an image of scattered lights into a linear shape at a linear irradiation site Lx where the sheet lights Ls cross with each other is provided. An optical fiber arrayhaving a plurality of optical fibersis provided at an image-forming position of the lens system. Avalanche photodiodesconfigured to convert the scattered lights which are shifted in frequency by the Doppler effect caused by the blood flow into electric signals for the each optical fiberare provided. The blood flow velocity in a tissue of a biological body at the linear irradiation site Lx is calculated from the scattered lights transformed from the laser light by being shifted in frequency by the Doppler effect and is scanned for the each optical fiber, whereby the blood flow velocity in the blood vessel in a predetermined area in the biological body is calculated.