An Efficient Time-Varying Filter for Detrending and Bandwidth Limiting the Heart Rate Variability Tachogram without Resampling: MATLAB Open-Source Code and Internet Web-Based Implementation

Table 1

approximation of −3 dB point [Hz].

True –3 dB cut-off frequency	Approximate frequency
0.05	0.049
0.1	0.102
0.2	0.208
0.3	0.34