Lu Yiqian, Yu Zengjie, Liu Jikui, An Qi, Chen Cong, Li Ye, Wang Yishan
Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, People's Republic of China.
University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
Physiol Meas. 2022 Jul 18;43(7). doi: 10.1088/1361-6579/ac7841.
Sympathetic nerve activity affects blood pressure by contracting the arteriole, which can increase systemic vascular resistance (SVR). Consequently, SVR is a key factor affecting blood pressure. However, a method for measuring SVR continuously is lacking. This paper formulated and experimentally validated a method that uses the arteriolar pulse transmit time (aPTT) to track changes in SVR.multi-wavelength photoplethysmogram (PPG), electrocardiogram (ECG), and galvanic skin response (GSR) data were simultaneously gathered using a measurement system designed by this study. Blood perfusion was monitored by laser Doppler. Least mean square (LMS) is an adaptive filtering algorithm. Our LMS-based algorithm formulated in this study was used to calculate the aPTT from the multi-wavelength PPGs. A cold stimulation experiment was conducted to verify the relationship between aPTT determined by algorithm and arteriole vasodilation. An emotinal stimulation experiment conducted, in which GSR was employed to further verify the relationship between aPTT and SVR. Twenty healthy young participants were asked to watch movie clips, which excited their sympathetic nerves. The dynamic time warping (DTW) distance is applied to evaluate between correlation of GSR and aPTT.The changes in aPTT was extracted using our LMS-based method. During the recovery period after cold stimulation, aPTT decreased with the average slope of -0.2080, while blood perfusion increased with the average slope of 0.7046. Meanwhile, 70% participants' DTW distances median between aPTT and GSR were significantly smaller than that between PTT and GSR during emotion stimulation.Our method uses aPTT, a continuous measurable parameter, to closely reflect SVR, as verified through experiments.
交感神经活动通过使小动脉收缩来影响血压，这会增加体循环血管阻力（SVR）。因此，SVR是影响血压的关键因素。然而，目前缺乏一种连续测量SVR的方法。本文提出并通过实验验证了一种利用小动脉脉搏传输时间（aPTT）来追踪SVR变化的方法。使用本研究设计的测量系统同时收集多波长光电容积脉搏波描记图（PPG）、心电图（ECG）和皮肤电反应（GSR）数据。通过激光多普勒监测血液灌注。最小均方（LMS）是一种自适应滤波算法。本研究中基于LMS制定的算法用于从多波长PPG中计算aPTT。进行了冷刺激实验以验证算法确定的aPTT与小动脉血管舒张之间的关系。进行了情绪刺激实验，其中采用GSR进一步验证aPTT与SVR之间的关系。20名健康的年轻参与者被要求观看电影片段，以激发他们的交感神经。应用动态时间规整（DTW）距离来评估GSR与aPTT之间的相关性。使用我们基于LMS的方法提取aPTT的变化。在冷刺激后的恢复期，aPTT以-0.2080的平均斜率下降，而血液灌注以0.7046的平均斜率增加。同时，在情绪刺激期间，70%参与者的aPTT与GSR之间的DTW距离中位数显著小于PTT与GSR之间的DTW距离中位数。我们的方法使用aPTT（一个可连续测量的参数）来密切反映SVR，实验已验证这一点
