Blood pressure and blood flow variation during postural change from sitting to standing: model development and validation
Blood pressure and blood flow variation during postural change from sitting to standing: model development and validation
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DOI：
10.1152/japplphysiol.00177.2005
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发表时间：
2005-10-01
影响因子：
3.3
通讯作者：
Novak, V
中科院分区：
文献类型：
--
作者：
Olufsen, MS;Ottesen, JT;Novak, V
从坐到站的姿势变化的短期心血管反应涉及调节血压的自主神经系统和维持脑灌注的脑自动调节之间的复杂相互作用。我们提出了一个数学模型，可以预测从坐到站的姿势变化期间逐搏动脉血压和大脑中动脉血流速度的动态变化。我们的心血管模型利用 11 个室来描述心脏和体循环中的血压、血流、顺应性和阻力。为了包括由于血压和血流的脉动性质而产生的动力学，使用压力的非线性函数对大的全身动脉的阻力进行建模。基于生理学的子模型用于描述姿势变化期间重力对静脉血池的影响。包括两种类型的控制机制：1）由交感神经和副交感神经反应介导的自主调节，影响心率、心肌收缩力、阻力和顺应性；2）由对肌源张力、代谢需求和二氧化碳浓度的局部变化的反应介导的自动调节，影响脑血管阻力。最后，我们制定了一个逆最小二乘问题来估计参数，并证明我们的数学模型与年轻受试者从坐到站的姿势变化期间的生理数据一致。
Shortterm cardiovascular responses to postural change from sitting to standing involve complex interactions between the autonomic nervous system, which regulates blood pressure, and cerebral autoregulation which maintains cerebral perfusion. We present a mathematical model that can predict dynamic changes in beat-to-beat arterial blood pressure and middle cerebral artery blood flow velocity during postural change from sitting to standing. Our cardiovascular model utilizes 11 compartments to describe blood pressure, blood flow, compliance, and resistance in the heart and systemic circulation. To include dynamics due to the pulsatile nature of blood pressure and blood flow, resistances in the large systemic arteries are modeled using nonlinear functions of pressure. A physiologically based submodel is used to describe effects of gravity on venous blood pooling during postural change. Two types of control mechanisms are included: 1) autonomic regulation mediated by sympathetic and parasympathetic responses, which affect heart rate, cardiac contractility, resistance, and compliance, and 2) autoregulation mediated by responses to local changes in myogenic tone, metabolic demand, and CO2 concentration, which affect cerebrovascular resistance. Finally, we formulate an inverse least-squares problem to estimate parameters and demonstrate that our mathematical model is in agreement with physiological data from a young subject during postural change from sitting to standing.