The power ratio of bands of low and high frequency in normalized units in the FFT method as a marker for quantitative assessment of the effectiveness of HRV biofeedback session

Abstract

HRV biofeedback is an effective method of relaxation and the fight against certain diseases. The effect exerted on the body has been documented many times. The main problem turned out to be a quantitative assessment of the effectiveness of the session. Among many characteristics which describe the variability of the heart rate, the power ratio of the high and low bands in units of normalized frequency obtained by the method of FFT(LF/HF) were selected to the survey.The aim of this study was to examine whether power ratio of bands of low and high frequency in normalized units obtained by the FFT methods is suitable for the quantitative description of the effectiveness of biofeedback session hrv .The study group consisted of 30 healthy people aged 21-25 years without any experience of the analyzed phenomenon. The study used a non-invasive method of measuring the blood flow through the ear of the participant, then the software program described it quantitatively.It turned out that the LF/HF cannot be used for quantitative evaluation of HRV BF session without further tests, but it is advisable to carry out long-term studies with the larger population of people. A surprising result was the observation of study participants, in short stage of relaxation, before the proper part of the study. Subjects knowing that soon they will participate in the active session mentally prepared themselves on the regulation of the breath which is confirmed by the results.