Zite He presents his Master's thesis

In this Master’s thesis, different multitaper methods are implemented to estimate the spectra of respiratory signals and heart rate variability (HRV) data, and further to estimate the correlation between the respiratory center frequency and the narrow-banded high frequency (HF) band of HRV power.

The methods are applied first on simulated ARMA-process data, then on the simulated integrated pulse frequency modulation (IPFM) data, where the evaluation is performed by calculating the bias and standard deviation of the narrow-banded HRV power and its correlation with the respiratory frequency. The results show that the Thomson multitaper and the peak matched multitaper has each own pros and cons on different type of signals and that the Thomson multitapers are the best giving the strongest negative correlation.

The second aim is to check whether the correlation deviates between subjects with different level of stress. A total number of 47 individuals, divided into 3 groups had their respirations and heart rates recorded. A clear difference is found indicating that the more stressed the stronger the correlation.