Abstract
The intravital microscope-television system already reported by the authors (JJBME 17, 1979), in which a two-channel sample hold scanner has been used to measure the microvascular blood flow velocity, was modified by introducing a one-bit correlator. The accuracy of velocity measurements by a new system and its applicability to blood flowmetry in microvessels have been examined by in-vitro and in-vivo experiments.
The correlator installed in the system made it possible to measure the real blood flow velocity automatically with inputs of the time-course signals from the two-channel sample hold scanner. Calibration experiments were performed by the rotating disk method and also by the in-vivo measurement of blood velocity in the rat mesentery with excellent results which follow : First, the peripheral speeds of a rotating disk marked by white radial lines were measured on the monitor TV screen. The measured velocity was found to agree well with the calculated one with a correlation coefficient of 1.0. Secondly, the flow velocity in the microvessels of rats obtained by correlation technique gave a good coincidence with that obtained by the previous method based on the visual measurement of delay time of blood flow signals.
