Simple size
In order to determine the number of samples, power analysis was performed using the G*Power (v3.1.9.7) program. The power of the study is expressed as 1-β (β = probability of type II error). In Liu et al.’s (2017) study evaluating the heart rate variability predicting the response to vagus nerve stimulation in patients with drug-resistant epilepsy, the measurement data of the control group (1064±562) and the data of the epileptic patient group, based on the mean and standard deviation values of LF Power, are (608±406) scores were reached (Liu et al, 2017). The effect size (d) was found to be 0.348 in the calculation made to obtain 80% power at the α=0.05 level of the study. Accordingly, it was determined that there should be 84 people in total for this study, which has 3 groups.