Production of a chewing robot for quantitative analysis of dynamic control mechanisms of jaw movements

本研究的目的是制造一种机器人，该机器人配备了控制机构，可以沿着正常人类下颌运动的轨迹进行下颌运动，并产生适合口内食物特性的咬合力。我们的目的是建立一个工程模型，定量分析动态最优控制人类下颌运动的神经肌肉机制。为了实现这一目标，我们根据以下设计原则制作了一个机器人，该机器人配备了一个控制单元和执行器，用于模拟人类下巴的运动：(1)在人体颅骨模型上实现下颌运动；(2)配备模拟人类合颌和开颌肌肉的致动器；(3)配备与感觉受体相对应的传感器，包括肌肉纺锤体和牙周机械感受器；(4)具有控制单元，产生下颌自主运动和反射运动的运动命令。随着该咀嚼机器人的制作，我们积累了正常受试者和患者咀嚼运动时颌部运动轨迹和颌部肌肉肌电图的记录，以描绘人类咀嚼颌部运动轨迹的特征以及咬合力的产生方式。此外，我们建立了一种诱导新生大鼠体外脑干-脊髓制剂中有节奏吸吮运动的方法。目前，我们正在尝试诱导年轻成年小鼠的有节奏咀嚼活动。

The purpose of this study was production of a robot equipped with a control mechnism for performance of jaw movements along the trajectory of normal human jaw movements and for generation of biting force suitable for properties of intraoral foods. We aimed to develop an engineering model for quantitative analysis of neuro-muscular mechanisms of dyanmic optimal control of human jaw movements.To achieve this goal, we produced a robot which was equipped with a control unit and actuators for simulation of human jaw movemets, on the basis of the following designing principles : (1) to achieve jaw movements on the human skull model, (2) to equip with actuators simulating human jawclosing and -opening muscles, (3) to furnish with sensors corresponding with sensory receptors, including muscle spindles and periodontal mechanoreceptors, (4) to possess a control unit producing the motor commands for voluntary and reflex jaw movements.Along with the production of this chewing robot, we accumulated records of trajectories of jaw movements and EMG of jaw muscles during chewing movements in normal subjects and patients, to delineate the characteristics of the trajectopry of human masticatory jaw movements as well as the mode of generation of biting force.In addition, we established a method for induction of rhythmical sucking movements in in vitro brainstem-spinal cord preparations from newnborn rats. At present, we are trying to induce rhythmical chewing activities in young adult mice.