Cardiorespiratory phase synchronization for Chan-meditation practitioners
|關鍵字:||希爾伯特-黃轉換;經驗模態分解法;心肺相位同步;HHT;EMD;Cardiorespiratory phase synchronization|
This research is aimed at the investigation of the effect of respiratory rate on cardiorespiratory phase synchronization (CRPS) for the Chan-meditation practitioners (experimental group) and normal, healthy people (control group). Cardiorespiratory phase synchronization was evaluated by the instantaneous phase of the heart-rate (HR) sequence and respiratory signal. Conventional linear method cannot provide a reliable estimate of instantaneous phase of HR sequence due to the possible interference of other biological artifacts to the HR activities. To deal with the issue, Hilbert-Huang transform (HHT) was adopted to decompose HR sequence. HHT has been applied to nonlinear signal processing recently. We aimed to attain a more precise estimate of instantaneous phase by HHT scheme. In this study, ECG (electrocardiograph) signals and respiratory signals of twelve subjects were recorded. Among them, six subjects were Chan-meditation practitioners and the other six subjects are normal people in the same age range, yet, without any meditation experience. The control group was requested to follow intentionally designed protocol in the recording, while the experimental subjects only practiced Chan meditation. In our preliminary results, control subjects exhibited significant better degree of CRPS in the session of breathing control at the rate of 10 breaths/min. One the other hand, experimental group did not exhibit significant correlation between CRPS and respiratory rate. According to the time-dependent respiratory signal, meditation practitioners breathed in a free style during Chan meditation and thus could not keep a constant respiratory rate for a moderate duration. The experimental group thus did not achieve the state of CRPS as good as the control group even at the same respiratory rate of 10 breaths/min. We thus make an assumption that a consistently slow respiration can induce an efficient CRPS.
|Appears in Collections:||Thesis|
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