Spectral Investigation of Heart Rate Variability Signals Using Stockwell-Transform

This paper discusses the use of Stockwell transform (ST) in time-frequency domain for spectral analysis of heart rate variability (HRV) signals. The ST is depicted numerically and compared with well-liked method of wavelet transform known as continuous Morlet wavelet transform (CMWT). The results of this study show that the normalized mean power and total normalized power in VLF (0.004Hz - 0.04Hz), LF (0.04 Hz - 0.15 Hz) and HF (0.15 Hz - 0.4 Hz) were improved as compared to CMWT for statistical significance value of p = 0.00016 and P <; 0.00001. For this analysis, Electrocardiogram (ECG) was recorded in fifteen normal subjects (mean age approximate 28 years, range 23 -34 years and mean hight approximate 162 Cms) in supine position for twenty minutes.