Impedance control and its relation to precision in orofacial movement.
Impedance control and its relation to precision in orofacial movement.
复制标题
阻抗控制及其与口面部运动精度的关系。
DOI：
10.1152/jn.90948.2008
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发表时间：
2009
影响因子：
2.5
通讯作者：
Ostry,DavidJ
中科院分区：
文献类型：
--
作者：
Laboissiere,Rafael;Lametti,DanielR;Ostry,DavidJ
言语的产生涉及到一些最精确和最精确的人类运动模式。在这里，在上下文中的下颌运动的讲话，我们表明，在语音生产的空间精度是系统地与阻抗的调节，特别是与下颌刚度的位移阻力的措施。我们估计的刚度和变化，在运动过程中使用机器人设备施加简短的力脉冲的下巴。刚度的估计值是使用扰动的位置和力的轨迹，并估计在没有负载的情况下的轨迹。我们使用一种基于傅立叶分析的新技术来估计这个“参考轨迹”。一个移动平均（MA）的程序被用来估计刚度建模恢复力作为移动平均值的以前的下巴位移。刚度矩阵由MA模型的稳态得到。我们应用这种技术的数据，从31名受试者的下颌运动受到干扰，在讲话和运动学匹配的非言语运动。我们观察到系统的差异，在整个过程中的下巴降低和下巴提高运动的运动学变异性的措施相关的刚度。当下颌抬高时，运动的早期和晚期下颌刚度较高，变异性较低。当下颌降低时，运动中间的刚度较低，变异性较高。在言语和非言语条件下观察到类似的模式。刚度和变异性之间的系统关系点的想法，刚度调节是不可或缺的口面运动变异性的控制。
Speech production involves some of the most precise and finely timed patterns of human movement. Here, in the context of jaw movement in speech, we show that spatial precision in speech production is systematically associated with the regulation of impedance and in particular, with jaw stiffness—a measure of resistance to displacement. We estimated stiffness and also variability during movement using a robotic device to apply brief force pulses to the jaw. Estimates of stiffness were obtained using the perturbed position and force trajectory and an estimate of what the trajectory would be in the absence of load. We estimated this “reference trajectory” using a new technique based on Fourier analysis. A moving-average (MA) procedure was used to estimate stiffness by modeling restoring force as the moving average of previous jaw displacements. The stiffness matrix was obtained from the steady state of the MA model. We applied this technique to data from 31 subjects whose jaw movements were perturbed during speech utterances and kinematically matched nonspeech movements. We observed systematic differences in stiffness over the course of jaw-lowering and jaw-raising movements that were correlated with measures of kinematic variability. Jaw stiffness was high and variability was low early and late in the movement when the jaw was elevated. Stiffness was low and variability was high in the middle of movement when the jaw was lowered. Similar patterns were observed for speech and nonspeech conditions. The systematic relationship between stiffness and variability points to the idea that stiffness regulation is integral to the control of orofacial movement variability.