Pulse waveforms are an indicator of the condition of vascular system

Abstract

Arterial stiffness index is one of the biomechanical indices of vascular healthiness. These indexes are based on detailed pulse waveform analysis which is presented here. After photoplethysmographyic (PPG) pulse wave measurement, we decompose the pulse waveform for the estimation and determination of arterial elasticity. Actually, it is electrooptically measured PPG signal that is analyzed and investigated by dividing each wave into five logarithmic normal function components. For the PPG waveform we can find a relative good fit between the original and overlapped and summed wave components. Each wave component is assumed to resemble certain phenomenon in the arteries and certain indexes can be calculated for example based on the mutual timing of the components. Several studies have demonstrated that these kinds of indexes which have been calculated based on actual biomechanical processes can predict future cardiovascular events. Many dynamic factors, e.g., arterial stiffness, depend on fixed structural features of the arterial wall. For more accurate description, arterial stiffness is indirectly estimated based on pulse wave decomposition analysis in the radial and tibial artery measured by PPG method in parallel. Elucidation of the precise relationship between endothelial function and arterial stiffness can be done through biomechanics. However, there is no clinically accepted technique for directly assessing the biomechanical properties of the arterial walls. Arterial wall elasticity awaits still further biomechanical studies with clinical relations and the influence of arterial flexibility, resistance and ageing inside of the radial pulse waveform.