Three-dimensional imaging techniques for microvessels using multipoint laser Doppler velocimeter

Abstract

We have succeeded in measuring the blood flow velocity in microvessels noninvasively, using an advanced multipoint laser Doppler velocimeter (M-LDV). We developed the M-LDV using a semiconductor laser with a wavelength of 785 nm and were able to improve the measurement of opaque fluids, including blood. Initially, the calibration of our equipment was checked by measuring the flow velocity of water in the glass tube with an inner diameter of 0.55 mm. These values were equal to that calculated from the indicated values of a flowmeter and succeeded in imaging the flow velocity distribution in the glass tube as two-dimensional images. Finally, we enlarged the optical magnification, and measured microvessels of an experimental mouse’s ear, and succeeded in imaging the blood flow velocity in microvessels as three-dimensional images. Compared with our previous report [T. Andoh et al., Jpn. J. Appl. Phys., Part 1 48, 017002 (2009)], the spatial resolution was improved by more than a factor of 10.