A grating laser microscope for measurements of blood flow velocity in microvessels.

A velocimeter for measurements of blood flow velocity in microvessels was constructed with a microscope, a grating, a photomultiplier and a wave-period measuring circuit. A differential detection system seemed to be useful when the probing area was extremely small. A pulsating flow velocity contour and the velocity reduction caused by an application of noradrenaline were on-line recorded in an arteriole of foot web of frogs.