Kinematical analysis of the linkage of the index finger on the basis of the posture measurement.

本研究的目的是研究食指的运动学参数(即连杆的长度，以及倾角和PIP关节角之间的配合)如何影响食指末端的可操作性。采用三维位置测量法对20名22~25岁受试者的食指屈伸进行了测量。利用测量数据建立了拇指和食指尖端收紧姿势下食指连动的运动学模型。采用三维测量方法，得到食指屈伸时的倾角与PIP关节角之间的对应关系。通过建立食指的运动学模型，利用倾角和PIP关节角之间的协调关系，得到了指尖速度到指尖夹角的转换。使用Mo…用更多的彭罗斯逆矩阵代替倾角和PIP角之间的配合，得到了指尖速度到关节角速度的转换。在拇指和食指三种捏指姿势下，将倾角和PIP关节角配合得到的指尖速度到关节角速度的转换结果与Moore Penrose逆矩阵得到的结果进行了比较。本研究测量的20名受试者的平均链长比为：(指尖到指关节轴的距离)：(指关节轴到指关节轴的距离)：(指关节轴到指关节轴的距离)=2.7：2.5：4.8。倾角与PIP角之间的协同作用呈S型曲线。在倾角和PIP关节角的协同作用下，指尖速度到关节角速度的转换与Moore-Penrose逆矩阵的转换非常相似。在结论中，确定了食指的运动学参数，从而可以通过输入最小运动幅度的角速度来控制指尖的运动。较少

The purpose of the present study is to investigate how the kinematic parameters of the index finger (i.e. the length of the link, and the cooperation between the DIP joint angle and the PIP joint angle) influence the manipulability of the tip of the index finger. The flexion and extension of the index fingers of twenty subjects who were 22-25 years old were measured using a three dimensional position measurement method. The kinematic model of the linkage of the index finger in the tip pinch posture of the thumb and index finger was developed using the measurement data. The cooperation between the DIP joint angle and PIP joint angle of the index finger in the flexion and extension was also obtained using the three dimensional measurement method. The transformation from the finger tip velocity to the joint angular velocities in the tip-pinch posture was obtained using the kinematic model of the index finger and the cooperation between the DIP joint angle and PIP joint angle. Using the Mo … More ore Penrose inverse matrix instead of the cooperation between the DIP joint angle and PIP joint angle enabled us to obtain the transformation from the finger tip velocity to the joint angular velocities. In three tip-pinch postures of the thumb and index finger, the transformation from the finger tip velocity to the joint angular velocities obtained from the cooperation between the DIP joint angle and PIP joint angle was compared with the one obtained from the Moore Penrose inverse matrix. The average ratio of the link lengths of twenty subjects measured in this study was as follows; (the distance between the tip of the finger and the DIP joint axis ):(the distance between the DIP joint axis and the PIP joint axis):(the distance between the PIP joint axis and the MP joint axis)=2.7:2.5:4.8. The cooperation between the DIP joint angle and the PIP joint angle was represented by a gentle sigmoid curve. The transformation from the velocity of the finger tip to the joint angular velocities with the cooperation between the DIP joint angle and the PIP joint angle was very similar to the one with the Moore-Penrose inverse matrix. In the conclusion, it was found that the kinematic parameters of the index finger were determined so that the motion of the finger tip could be controlled by the input of the angular velocities whose magnitude was the minimum in motion. Less