Evaluating functional roles of phase resetting in generation of adaptive human bipedal walking with a physiologically based model of the spinal pattern generator
Evaluating functional roles of phase resetting in generation of adaptive human bipedal walking with a physiologically based model of the spinal pattern generator
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DOI：
10.1007/s00422-010-0373-y
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发表时间：
2010-05-01
影响因子：
1.9
通讯作者：
Tsuchiya, Kazuo
中科院分区：
文献类型：
--
作者：
Aoi, Shinya;Ogihara, Naomichi;Tsuchiya, Kazuo
脊髓中的中央模式发生器（CPG）对运动行为有很大的贡献。为了实现自适应运动，运动节律产生的CPGs的功能调制相位重置的基础上感觉传入或扰动。虽然在猫的虚构运动中已经研究了相位重置，但其在实际运动中的功能作用尚未阐明。最近，已经进行了模拟研究，以检查在人类双足步行过程中的相位重置的作用，假设运动产生的基础上规定的运动学和反馈控制。然而，这种基于运动学的建模不能用来充分阐明适应机制。在这篇文章中，我们提出了一个更生理基础的数学模型的神经系统的运动和研究的功能作用的相位重置。我们构建了一个运动CPG模型的基础上的节奏发生器（RG）和模式形成（PF）网络的两层层次网络模型。RG模型使用相位振荡器产生节律信息，并通过基于脚接触信息的相位重置来调节节律信息。PF模型基于节奏信息创建前馈命令信号，该节奏信息由基于先前对肌肉协同作用的分析的五个矩形脉冲的组合组成。仿真结果表明，我们的模型建立了自适应步行对扰动力和环境的变化，相位重置在增加响应的鲁棒性中发挥重要作用，这表明这种调节机制可能有助于产生自适应人类双足运动。
The central pattern generators (CPGs) in the spinal cord strongly contribute to locomotor behavior. To achieve adaptive locomotion, locomotor rhythm generated by the CPGs is suggested to be functionally modulated by phase resetting based on sensory afferent or perturbations. Although phase resetting has been investigated during fictive locomotion in cats, its functional roles in actual locomotion have not been clarified. Recently, simulation studies have been conducted to examine the roles of phase resetting during human bipedal walking, assuming that locomotion is generated based on prescribed kinematics and feedback control. However, such kinematically based modeling cannot be used to fully elucidate the mechanisms of adaptation. In this article we proposed a more physiologically based mathematical model of the neural system for locomotion and investigated the functional roles of phase resetting. We constructed a locomotor CPG model based on a two-layered hierarchical network model of the rhythm generator (RG) and pattern formation (PF) networks. The RG model produces rhythm information using phase oscillators and regulates it by phase resetting based on foot-contact information. The PF model creates feedforward command signals based on rhythm information, which consists of the combination of five rectangular pulses based on previous analyses of muscle synergy. Simulation results showed that our model establishes adaptive walking against perturbing forces and variations in the environment, with phase resetting playing important roles in increasing the robustness of responses, suggesting that this mechanism of regulation may contribute to the generation of adaptive human bipedal locomotion.