Table 3 Description of HRV nonlinear features.
Feature | Unit | Description |
|---|---|---|
RR-sd1 | ms | Width of the fitted ellipse on the Poincaré plot |
RR-sd2 | ms | Length of the fitted ellipse on the Poincaré plot |
RR-s-area | ms | Area of the fitted ellipse on the Poincaré plot |
RR-sd-ratio | - | Ratio of SD1-to-SD2 |
RR-sample-ent | - | Sample entropy, measures the irregularity and randomness of a time series |
RR-perm-ent | - | Permutation entropy, measures the irregularity and randomness of a time series |
