COMPARISON BETWEEN A NEW COMPUTERIZED AND AN ANALOG VIDEOPHOTOMETRIC, CROSS-CORRELATION TECHNIQUE FOR MEASURING SKIN CAPILLARY BLOOD-CELL VELOCITY IN HUMANS

The capillary blood cell velocity (CBV) was measured using two different cross-correlation systems. Cross-correlation was performed by (1) a self-tracking, analogue cross-correlation technique and (2) by a new fully computerized system. The CBV was measured at rest and during venous occlusion and postocclusive reactive hyperemia (PRH) after 1-min arterial occlusion. The PRH response was described by determining the peak CBV. The correlations between the values obtained by the two systems were highly significant. CBV at rest: r = 0.97 (p < 0.001); CBV during venous occlusion: r = 0.97 (p < 0.001), peak CBV during PRH: r = 0.97 (p < 0.001). The stability of measurements with the computerized system was high. Only 0.08% of CBV variations was due to repeated measurements. This computerized system represents a reliable innovation which greatly facilitates CBV measurements, especially in clinical practice. The program includes automatic calculation of data (mean and maximum and minimum CBV, area under the curve, and integral, etc.).