Autocorrelation algorithm for determining a pulse wave delay

Abstract

This article concerns an autocorrelation algorithm for determining a pulse wave delay. The pulse wave delay is defined as difference between the characteristic points i.e. the difference between the R wave in the electrocardiogram signal (ECG) and distinctive point in the photoplethysmogram (PPG) waveform. Obtaining values of the characteristic points (time stamps) are realized by correlation function. The known values of the time stamps can be used to estimate change of blood pressure. In the proposed algorithm using the autocorrelation function is calculated signal pattern. Then, this pattern is used for further correlation calculations. In the algorithm all the time is analysed the quality of the measured signal. In the next part of article was described method of measurement and the results calculated the time of the characteristic points to determine the pulse wave delay.