A calibration standard for laser‐Doppler perfusion measurements

The objective of the present study was the development of a new calibration standard for the laser‐Doppler perfusion monitors. The beat frequency spectrum obtained from a solution of latex spheres undergoing Brownian motion was compared to that obtained from a porous polyethylene material containing the same solution. The mixture of static and dynamic scattering events in the latter case was expected to produce a spectrum similar to that obtained in the real human tissue. The results obtained demonstrate clearly the difference between the signals recorded from the commonly used motility standard which are the result of multiple Doppler shifting and homodyne mixing, and those generated from our enhanced model which predominantly result from single Doppler shifting and heterodyne mixing.