| Popis: |
The authors proposes a method to study the non-stationary heart rhythmogram based on the wavelet analysis of a frequency-modulated signal. The peaks of the cardiogram coincide with heart contractions. The study included a test with controlled breathing, which consisted of three stages: a resting stage (A), a rhythmic breathing stage with a given frequency (B), and a relaxation stage (C). The duration of stages A, B and C were 15, 5 and 20 minutes, respectively. The rhythmic breathing stage B consisted of an inhalation/exhalation sequence, each lasting 5 seconds. Breathing tests were performed on 27 apparently healthy subjects aged 18–22. The quantitative parameters discussed in the article are the ratios of the spectral integrals of the frequency modulated signal of the heart rhythm. Spectral integrals were calculated for the ultra-low, low and high frequency ranges at stages A, B, and C. The subjects were classified according to their response to the breathing test. The proposed method can be used in the analysis of transient responses of the rhythmogram in all functional tests. |
