中文摘要：

研究了引导呼吸下心血管参数变化情况,观察引导呼吸对心血管系统的累积作用效果。采用了呼吸率由高到低渐进性变化的呼吸运动模板,同步观察了心率变异性、血压和脉搏波传导时间的变化规律。实验结果表明,在渐进性引导呼吸过程中,随着呼吸率的降低,呼吸运动对心率、血压和脉搏波传导时间的幅度调制作用显著增强（p〈0.05）,同时脉搏波传导时间延长,血压下降。该引导呼吸模式具有显著降低血压的作用效果（p〈0.05）,脉搏波传导时间基线可作为一个有效的指标来表征引导呼吸的作用效果。

英文摘要：

To investigate the effect of paced breathing on cardiovascular system, the cardiovascular variables of heart rate, blood pressure and pulse transit time （PTT） were measured during a stepwise paced breathing procedure （six different breathing rates at [14, 12.5, 11, 9.5, 8, 7]BPM）. Respiratory sinus arrhythmia （RSA） was estimated by using autoregressive （AR） model based power spectral analysis. The ensemble empirical mode decomposition （EEMD） was applied to PTT to decompose the signal into different intrinsic mode function, and respiration-derived oscillation and trend component （baseline） in PTT were extracted for further analysis. The results clearly indicate that the stepwise paced breathing procedure can induce increased oscillations in RSA, blood pressure and PTT, meanwhile, reduce blood pressure and lengthen PTT baseline. It was demonstrated that this stepwise paced breathing procedure can lead to blood pressure reduction significantly （p〈0.05）, and PTT can be used as a maker for the effect of paced breathing on cardiovascular system.