PC-based noninvasive measurement of the autonomic nervous system. Detecting the onset of diabetic autonomic neuropathy

The IBM PC-based system and experimental results presented here describe a new approach to recording electrophysiological signals associated with the autonomic nervous system, and the detection of the changes in electrophysiological signals due to onset of diabetic autonomic neuropathy. The authors have shown that the skin sympathetic sudomotor activity has much lower amplitude due to the functional state of the ANS caused by the diabetic neuropathy. The skin transient pulse blood (STPB) amplitude over many sweeps is statistically correlated with the laser Doppler flowmetry amplitude, but the photoplethysmographic technique is less expensive. Spectral analysis of STPB in the frequency range 0.5-2 Hz enables the separate assessment of parasympathetic and sympathetic activities and the rapid detection of cardiac autonomic neuropathy.