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首页> 外文期刊>American Journal of Physiology >Resonance in a mathematical model of baroreflex control: arterial blood pressure waves accompanying postural stress.
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Resonance in a mathematical model of baroreflex control: arterial blood pressure waves accompanying postural stress.

机译：压力反射控制数学模型中的共振：伴随姿势压力的动脉血压波。

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A mathematical model of the arterial baroreflex was developed and used to assess the stability of the reflex and its potential role in producing the low-frequency arterial blood pressure oscillations called Mayer waves that are commonly seen in humans and animals in response to decreased central blood volume. The model consists of an arrangement of discrete-time filters derived from published physiological studies, which is reduced to a numerical expression for the baroreflex open-loop frequency response. Model stability was assessed for two states: normal and decreased central blood volume. The state of decreased central blood volume was simulated by decreasing baroreflex parasympathetic heart rate gain and by increasing baroreflex sympathetic vaso/venomotor gains as occurs with the unloading of cardiopulmonary baroreceptors. For the normal state, the feedback system was stable by the Nyquist criterion (gain margin = 0.6), but in the hypovolemic state, the gain margin was small (0.07), and the closed-loop frequency response exhibited a sharp peak (gain of 11) at 0.07 Hz, the same frequency as that observed for arterial pressure fluctuations in a group of healthy standing subjects. These findings support the theory that stresses affecting central blood volume, including upright posture, can reduce the stability of the normally stable arterial baroreflex feedback, leading to resonance and low-frequency blood pressure waves.
机译：建立了动脉压力反射的数学模型，并用于评估反射的稳定性及其在产生低频动脉血压振荡（称为Mayer波）中的潜在作用，这种频率在人和动物中普遍存在，是对中央血容量减少的反应。该模型由离散时间滤波器的布置组成，这些滤波器是从已发表的生理研究中得出的，该滤波器被简化为压力反射开环频率响应的数值表达式。对两种状态的模型稳定性进行了评估：正常和中央血容量减少。通过减少压力反射性副交感神经心率的增加和增加压力反射性交感性血管/静脉运动的增加来模拟中心血容量减少的状态，如心肺压力感受器卸载时发生的那样。对于正常状态，根据奈奎斯特准则，反馈系统是稳定的（增益裕度= 0.6），但是在低血容量状态下，增益裕度很小（0.07），并且闭环频率响应呈现出尖锐的峰值（增益为0.6）。 11）在0.07 Hz下，与在一组健康站立的受试者中观察到的动脉压波动频率相同。这些发现支持这样一种理论，即影响包括直立姿势在内的中央血容量的应力会降低正常稳定的动脉压力反射反馈的稳定性，从而导致共振和低频血压波。

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