Closed-Loop Dynamic Modeling of the Heart-Rate Reflex to Concurrent Spontaneous Changes of Arterial Blood Pressure and CO2 Tension: Quantification of the Effects of Mild Cognitive Impairment.
Closed-Loop Dynamic Modeling of the Heart-Rate Reflex to Concurrent Spontaneous Changes of Arterial Blood Pressure and CO2 Tension: Quantification of the Effects of Mild Cognitive Impairment.
复制标题
心率反射对动脉血压和二氧化碳张力同时自发变化的闭环动态建模：轻度认知障碍影响的量化。
DOI：
10.1109/tbme.2021.3070900
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Zhang,Rong
中科院分区：
文献类型：
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作者：
Marmarelis,Vasilis;Shin,Dae;Zhang,Rong
目的：扩展心率反射(HRR)的闭环模型，包括同时变化的血二氧化碳分压的动态效应。这个扩展的动态模型可以用来产生“压力反射增益”(BRG)和“化学反射增益”(CRG)的生理标记物，从而可以定量评估病理对HRR的可能影响。以轻度认知损害(MCI)为例。方法：基于数据的闭环建模方法通过对两个开环模型进行Laguerre核展开来估计模型的正向和反向动态分量。随后，通过模拟所获得的动脉压或二氧化碳分压单位阶跃变化的闭环模型，分别计算每个受试者的脉搏波和脉搏波生理标记物。结果：开环和闭环心率变异性模型均显示，与对照组相比，轻度认知障碍患者的脉搏波显著减小(p<；0.001)，但脉搏波波幅无显著差异。此外，闭环模型在化学反射和压力反射传递函数中捕捉到交感神经活动的动态效应，作为0.1赫兹附近的共振峰(Mayer波)(不是通过开环模型捕捉的)。这可能有助于我们进一步理解交感神经活动如何在不同的病理过程中影响心率。结论：扩展的心率反应模型包含了同时变化的血二氧化碳分压的动态效应，显示MCI患者的化学反射增益显著降低(但压力反射增益不明显)。此外，闭环模型还捕捉到了0.1 Hz附近的交感神经影响。意义：多变量闭环动态建模对于理解生理自动调节具有重要意义。
Objective: To extend closed-loop modeling of the heart-rate reflex (HRR) by including the dynamic effects of concurrent changes in blood CO2 tension. This extended dynamic model can be used to generate physio-markers of “baroreflex gain” (BRG) and “chemoreflex gain” (CRG) that allow quantitative assessment of the possible impact of pathologies upon HRR. Mild Cognitive Impairment (MCI) is used as an example.Methods: The proposed data-based closed-loop modeling methodology estimates the forward and reverse dynamic components of the model via Laguerre kernel expansions of two open-loop models using spontaneous time-series data collected in 45 MCI patients and 15 controls. The BRG and CRG physio-markers are subsequently computed for each subject via simulation of the obtained closed-loop model for unit-step change of arterial pressure or blood CO2 tension, respectively.Results: Both open-loop and closed-loop HRR modeling revealed that MCI patients exhibit significantly smaller CRG relative to controls (p<0.001), but not significantly different BRG. Furthermore, the closed-loop model captured the dynamic effect of sympathetic activity as resonant peak around 0.1 Hz (Mayer wave) in the chemoreflex and baroreflex transfer functions (not captured via open-loop modeling). This may prove valuable in advancing our understanding of how sympathetic activity impacts HRR in various pathologies.Conclusion: The extended HRR model, incorporating the dynamic effects of concurrent changes of blood CO2 tension, revealed significantly reduced chemoreflex gain (but not baroreflex gain) in MCI patients. Furthermore, the closed-loop model captured the sympathetic influence around 0.1 Hz.Significance: Multivariate closed-loop dynamic modeling is valuable for understanding physiological autoregulation.