Study of skin hemodynamics with fast dynamic area telethermometry (DAT)

Dynamic area telethermometry (DAT) is a highly useful in the study of the physiology or pathophysiology of the vascular system and its neuronal control. DAT entails acquisition of hundreds of consecutive infrared images, facilitating the quantitative analysis of the modulation of cutaneous temperature and of its spatial homogeneity. This analysis, which characterize the dynamics of skin perfusion, allows the assessment of local and systemic hemodynamics by a fast, inexpensive, non-contact procedure. DAT can be applied in different time frames, analyzing fast and relatively slower neuro-vascular hemodynamic processes, depending on the rate of data acquisition. Here, the authors describe the application of fast DAT to monitor the effect of the dynamics of the cardiac cycle on the perfusion of the peripheral skin. Using a 256/spl times/256 FPA Ga/As quantum well infrared photodetector (QWIP) camera at a rate of 66 frames per second the authors monitored hemodynamic processes which modulate peripheral skin temperature 10 to 50 millidegrees. The authors have shown that while the size of the sampled area is not critical for the interpretation of hemodynamic processes, studying the thermal dynamics of a cluster of many small areas allows to determine the directionality of cutaneous blood flow.