探討禪坐組、呼吸控制組與心智壓力組的血壓脈波傳輸時間

Abstract

本研究的目的主要探討心智壓力狀態下、呼吸調控與禪坐調息時的血壓脈波傳輸時間(Pulse Transit Time)影響。血壓脈波傳輸時間(PTT)與血壓具有高相關性，進而探討與心智壓力之間的變化。本研究共收集了31位年齡相似受測者的心電圖、光體積變化描計圖和呼吸訊號，其中實驗組為10位具有禪坐經驗者，而呼吸控制組(控制-I)14位和心智壓力組(控制-II)7位受測者則無此經驗。由結果發現，呼吸控制組在心跳速率快的情況下，血壓脈波傳輸時間(PTT)和呼吸速率呈負相關性，PTT隨著呼吸變慢而增加，而心智壓力的結果會造成PTT縮短，正常情況下，人在放鬆時的PTT比在有壓力狀態時長。因此，我們可以假設當人感受到壓力時，緩慢的深呼吸會使人變得比較輕鬆。另一方面，禪坐組在心跳速率快時，並無顯著現象，由於冥想能夠協調身體不同器官的運作，禪坐練習者在心率快情況下仍維持放鬆狀態。

This study is aimed at the investigation of PTT (Pulse Transit Time) behaviors under breathing control (control-I group), mental stress (control-II group), and Chan meditation (experimental group). Research shows that the PTT highly correlates with the changes in blood pressure. Therefore, correlation between PTT and the mental stress was also investigated. In this study, ECG (electrocardiograph), PPG (photoplethysmograph) and respiratory signals were recorded for three groups, experimental group including ten Chan-meditation practitioners, control-I group including fourteen subjects under breathing-control trial and control-II group including seven subjects treated by mental-stress test. Both control groups are normal, healthy subjects in the same age range as the experimental group, yet, without any meditation experience. In our preliminary results, all control-I subjects exhibit negative relation between PTT and RR under fast HR, that is, PTT increases with the slowdown of respiration. In the control-II group, mental test induces the physical stress that makes the PTT shorter. Normally, a longer PTT reveals a relaxed state of cardiac activity. Consequently, we may conclude that people can experience that they become relaxed after a few slow respiration with deep inhalation and exhalation when they were under stress. On the other hand, only two out of ten subjects in the experimental group exhibit negative correlation in the fast HR range. The phenomenon of negative correlation in the fast HR range implies that Chan-meditation practice can maintain the state of relaxation while heart beating at the fast rate. Since Chan meditation mostly harmonizes the operation of different organ systems in the body, PTT might be maintained at a stable level.