Patent ID: 9031640
Filing Date: 2015-05-12
Classification: A61B

Abstract:
1. A laser Doppler blood flow measuring method comprising: splitting infrared laser light emitted from a laser light source into split laser lights, transforming the split laser lights into thin sheet lights, and crossing the sheet lights with each other at a linear irradiation site at a position in a biological body, wherein the sheet lights are scattered into scattered lights at the linear irradiation site, and wherein among the scattered lights, scattered lights which are scattered by blood cells in a blood flow in a blood vessel in the biological body are shifted in frequency due to the Doppler effect, and scattered lights which are scattered by stationary tissue are not shifted in frequency due to the Doppler effect; receiving, by an optical system, the scattered lights from the linear irradiation site; emitting the scattered lights from the optical system such that the scattered lights are in a linear shape and are emitted onto a plurality of light-receiving elements which are arranged in a linear shape; performing photoelectric conversion of the scattered lights by a plurality of photoelectric conversion elements which correspond to the plurality of light-receiving elements to obtain electric signals corresponding to the scattered lights; processing the electric signals obtained by the photoelectric conversion, to obtain frequencies of the scattered lights; obtaining positional information about the blood vessel in the biological body from positions of ones of the plurality of light-receiving elements which receive the scattered lights which have been shifted in frequency by the Doppler effect; and calculating a blood flow velocity in the blood vessel using Doppler frequency shifts of the scattered lights which were scattered by the blood cells in the blood flow; wherein the method further comprises scanning the sheet lights to move the linear irradiation site in two directions orthogonal to a longitudinal direction in which the linear irradiation site extends and along a direction parallel to the longitudinal direction, and obtaining information about the blood flow in the blood vessel in three dimensions using the frequencies of the scattered lights at a plurality of positions to which the linear irradiation site is moved by the scanning; and wherein the obtaining of the information about the blood flow in the blood vessel in three dimensions includes obtaining the positional information about the blood vessel and obtaining the blood flow velocity in the blood vessel at the plurality of positions to which the linear irradiation site is moved by the scanning.