Noninvasive In-vivo Measurements of Microvessels by Reflection-Type Micro Multipoint Laser Doppler Velocimeter

Abstract

We have developed a micro multipoint laser Doppler velocimeter (µ-MLDV) that enables selective collection of Doppler interference photons. In previous report [H. Ishida et al.: Rev. Sci. Instrum. 82 (2011) 076104], developed the reflection-type µ-MLDV, and showed the results of demonstrations performed on transparent artificial flow channels. In this study, we attempted to perform in-vivo experiments using animals. It can measure absolute velocity and generate tomographs of blood vessels courses. The present system can perform noninvasive in-vivo measurements with a detection limit of about 0.5 mm/s and a spatial resolution in the x–y plane of 125 µm. It is thus able to image venulae. It was used to image venulae in a mouse ear and a subcutaneous blood vessel in a mouse abdomen at a depth of about 1.0 mm below the skin.

High-resolution in-situ LDV monitoring system for measuring velocity distribution in blood vessel

“…In a previous study, we demonstrated that an L-MLDV system could be used to visualize the blood flow in the capillaries of a mouse [28][29][30]. However, the values in our velocity images were averaged over the measurement period (1.0 s), and the possibility of simultaneous blood flow measurements at all points in the imaged area was not discussed.…”