Wilson Emma, Rustighi Emiliano, Mace Brian R, Newland Philip L
Institute of Sound and Vibration Research, University of Southampton, Southampton, Hampshire, SO17 1BJ, UK.
Biol Cybern. 2010 Jun;102(6):503-11. doi: 10.1007/s00422-010-0382-x. Epub 2010 Mar 26.
A mathematical model of the locust hind leg extensor muscle is described. The model accounts for the force response of the muscle to well-separated input stimuli under isometric conditions. Experimental data was collected by stimulating the extensor muscle and measuring the force generated at the tibia. In developing a model it was assumed that the response to a single isolated stimulus was linear. A linear model was found to fit well to the response to an isolated stimulus. No assumptions were made about the model order and models of various order were fitted to data in the frequency domain, using a least squares fit. The stimulus can be approximated as an impulse, with the response to each stimulus well described by a linear second-order system. Using a third-order model provided a better fit to data, but the improvement in fit was marginal and the model uses one extra parameter. A fourth-order model, which is often used to describe the behaviour of isometric muscle was found to overfit the data. Using a second-order model provides a simpler way of describing the behaviour of an isometric twitch.
本文描述了一种蝗虫后腿伸肌的数学模型。该模型解释了在等长条件下肌肉对间隔良好的输入刺激的力响应。通过刺激伸肌并测量胫骨产生的力来收集实验数据。在开发模型时，假设对单个孤立刺激的响应是线性的。发现线性模型能很好地拟合对孤立刺激的响应。未对模型阶次做任何假设，使用最小二乘法拟合，将不同阶次的模型在频域中拟合数据。刺激可近似为一个脉冲，对每个刺激的响应可用线性二阶系统很好地描述。使用三阶模型对数据拟合得更好，但拟合的改善很微小，且该模型多使用了一个参数。发现常用于描述等长肌肉行为的四阶模型对数据过度拟合。使用二阶模型提供了一种描述等长抽搐行为的更简单方法。
