Measurement of red cell velocity with a two-slit technique and cross-correlation: Use of reflected light, and either regulated dc or unregulated ac power supplies

The data illustrate red cell velocity values obtained from microvessels of brain and muscle by utilizing a two-slit technique and cross-correlator in settings employing reflected light. Similarities are shown between these data and data obtained or reported from transilluminated vessels. These similarities include relative independence of apparent centerline velocities on the plane of focus, and relatively low ratios of velocities at the center to velocities near the wall. It is shown, in addition, that accurate velocity measurements can be made utilizing a nonregulated ac power supply, although it cannot be stated that such measurements could be obtained in circumstances other than those described.