Consideration on parameter determination of a new model describing dynamic vagal heart rate control in rats.
Consideration on parameter determination of a new model describing dynamic vagal heart rate control in rats.
复制标题
描述大鼠动态迷走神经心率控制的新模型参数确定的考虑。
DOI：
10.1109/embc.2012.6346797
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Sugimachi M.
中科院分区：
文献类型：
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作者：
Kawada T;Uemura K;Shimizu S;Kamiya A;Turner MJ;Mizuno M;Sunagawa K;Sugimachi M.
迷走心率控制的动态特性可以用纯死时间一阶低通滤波器近似描述。然而，该模型不一定是大鼠心率控制迷走神经传递函数的最佳近似值，因为增益图中约0.3 Hz以上的部分较为平坦。我们开发了一个新的模型，其中包括一个与频率无关的增益项，以重现在大鼠迷走神经传递函数中看到的增益图的平坦部分。新术语的加入增加了对迷走神经刺激下实测心率与预测值心率线性回归关系的外部验证的决定系数，并使回归线的斜率更接近于一致。在频域和时域上确定了数学传递函数的参数。频域拟合提供了一组参数，这些参数也能够很好地再现时域阶跃响应。相比之下，时域拟合提供了一组参数，可再现频率域传递函数，最高可达0.2 Hz。确定合适的模型参数对于建立描述迷走神经刺激下大鼠动态心率反应的新模型至关重要。
The dynamic characteristics of vagal heart rate control can be approximated by a first-order low-pass filter with pure dead time in rabbits. However, this model may not necessarily be the best approximation of the vagal transfer function of the heart rate control in rats, because a flatter portion exists in the gain plot above approximately 0.3 Hz. We developed a new model that includes a frequency-independent gain term to reproduce the flatter portion of the gain plot seen in the vagal transfer function in rats. The inclusion of the new term increased the coefficient of determination in an external validation of the linear regression relationship between measured and predicted heart rate responses to vagal stimulation, and made the slope of the regression line closer to unity. The parameters of mathematical transfer functions were determined in both the frequency and time domains. The frequency-domain fitting provided a set of parameters that was also able to reproduce the time-domain step response reasonably well. In contrast, the time-domain fitting provided a set of parameters that reproduced the frequency-domain transfer function only up to 0.2 Hz. Determination of proper model parameters was crucial for the development of a new model to describe the dynamic heart rate response to vagal stimulation in rats.