ADVANTAGE OF MONITORING SKIN VIBRATION AS AN INDEX OF ARTERIOVENOUS FISTULAR BLOOD-FLOW

Monitoring of the skin vibration is disturbed little by environmental noise. Therefore, the skin vibration is more relevant than bruit on th e skin by means of monitoring the fistular blood flow. Frequency analy sis of the skin vibration generated by an internal arteriovenous fistu la indicated two peaks of power spectral density (PSD), one in the fre quency range of 4-10 Hz and the other from 100-300 Hz. The analysis of the skin vibration generated by an external fistula, however, showed only one peak in the range of 4-10 Hz and a moderate flat PSD level in the range of 100-300 Hz. The PSD level in the range of 100-300 Hz dec reased dramatically or disappeared when the fistular blood flow dimini shed or ceased. Therefore, the optimal frequency for monitoring skin v ibration may be the range of 100-300 Hz.