Method for ascertaining the pressure pulse and related parameters in the

Abstract

The system measures the pressure pulses in an upper body peripheral artery and produces an electrical signal which represents the contours of these pulses. It then digitizes the signal and synthesizes the pressure pulses in the ascending aorta using either a frequency-domain or a time-domain calculation method. Next, the system separately averages the signals corresponding to the measured pulses and those corresponding to the synthesized pulses, and forms for each an 'average pulse.' The system identifies the wave foot in each of the average pulses, identifies the incisura in the average peripheral pulse, determines the amount of time associated with systole and, based on this time, segments the synthesized pulse into systolic and diastolic components. The system then identifies the two pressure peaks and determines their amplitudes using either the average peripheral pulse or the average synthesized pulse, by taking first and third derivatives of the pulses and determining the locations of the relevant minimum and maximum points. The system then determines the peak and mean pressures throughout the wave and at various critical points such as the primary pressure peak, the reflective wave peak, and throughout systole and diastole. Using these peaks and pressures, the system calculates maximum and mean systolic and diastolic pressures, an augmentation index, a measure of subendocardial viability, and the pressure at the end of systole.