Comparison of four calculation techniques for estimation of local arterial compliance

Abstract

Local arterial compliance of finger arteries C is derived from the recorded pressure and volume waveforms during cuff inflation applying four different estimation techniques. While the first algorithm Camplit =ΔV/ΔP (where ΔP is the finger arterial pulse pressure and ΔV is the corresponding pulsatile volumetric change) takes into account the whole amplitude of pulses, the other three estimates use synchronous fragments of pressure and volume waveforms in their upstroke, downstroke and top area, respectively (slope-based estimation). Finger pressure and volume waveforms are recorded by the Finapres monitor (Ohmeda, USA) and the UT9201 physiograph (University of Tartu, Estonia), respectively. Results in 13 volunteers demonstrate that the slopebased estimation gives higher compliance values and steeper peaks of the compliance vs. transmural pressure relationship compared to the amplitude-based estimation. The best results regarding the noise component were obtained by the amplitude- based estimation. Among the slope-based techniques, the top fragment based estimation introduced less fluctuation compared to the upstroke or downstroke fragment based estimation.