P.047 Examination of Pressure and Volume Pulse Waves

Abstract

Measurements of the arterial pulse were made at the brachial, carotid, and radial artery. The pressure and volume waveforms were obtained using piezoelectric and optical sensors, respectively. The data were digitized using a digital storage oscilloscope interfaced with a personal computer. The time between velocity maxima of the two waveforms was computed after Savitzky-Golay filtering. In the absence of arterial expansion, the derivative of the volume waveform matched the shape of the pressure waveform. Volume waveforms were found to lag pressure waveforms. Comparisons of the pressure and volume waveforms in two arms were made for different positions of the arms. Control measurements were taken with both hands at heart level. Zero time differential between the pairs of similar sensors was observed. The shapes of the pressure waveforms matched, as did those of the volume waveforms. As one arm was extended vertically, a time differential between the pressure waveforms and the volume waveforms appeared, with the pulse observed later in the extended arm. The time differential between the pressure and volume sensor on the extended arm appeared to lengthen, as did the width of the volume waveform. When the arm was returned to heart level, the shape of the volume pulse returned to normal over a maximum time of 35 seconds. When an arm was lowered, the pressure waveforms remained unchanged, but the volume waveform in the lowered arm was observed prior to the arrival of the volume waveform in the control arm.