Arterial pulse waveform dependence on applied pressure

The arterial pulse waveform dependence on applied pressure was experimentally analyzed. An experimental device was built and tests were conducted. Pressure was applied to the brachial artery and the analysed photoplethysmographic waveform was registered from radial artery. The photoplethysmographic signal was analyzed by calculating the differences between pulse waveforms. In addition waveform amplitude and the slope of the rising front were studied. When the applied pressure was lowered to the level where the piezoelectric signal amplitude is near its maximum, the differences between pulse waveforms decrease. It was concluded that there is a critical pressure level and below this the waveform is no longer influenced.