上肢康复训练机器人虚拟环境建模技术

Virtual environment building for a rehabilitative robot of the upper-limb

目的:以往基于虚拟环境的康复训练系统大多数强调视觉反馈,实验针对单自由度上肢康复训练机器人系统,建立康复训练的人机交互虚拟环境,在训练过程中利用力反馈和视觉反馈为患者提供暗示和帮助,并验证其可行性。方法:单自由度上肢康复训练机器人系统可以绕轴心进行反复的圆弧运动,对实际运动和虚拟环境中的路径进行映射,建立三个不同级别的康复训练虚拟环境模型。患者通过机械臂跟踪虚拟环境中的引导小球,并控制虚拟小球的运动,患肢的运动结果以视觉反馈的形式显示在屏幕上。同时,在规划路径周围构建虚拟力势场,根据实际运动与预测运动的位置误差为患者提供相应的力反馈,提示并帮助患者向正确的方向运动。利用该系统对一名健康女性进行初步的实验研究。结果:①虚拟环境实现了患肢的实际运动到虚拟运动的映射,患者可通过机械臂控制虚拟物体的运动。②当患肢实际运动与预测的位置存在误差时,虚拟环境可以通过训练机械臂为患者提供力反馈。结论:利用该思路构建的虚拟环境可以实现康复训练过程中的力觉和视觉交互,为患者提供及时的暗示和帮助,在康复训练机器人领域有一定的应用前景。

AIM： Most of the previous rehabilitation trainings based on virtual environment pay attention to visual feedback. In this study, an interactive virtual environment for one-degree of freedom （DOF） rehabilitation robotic system for upper-limb was built to provide the implication and help for patients using force and visual feedback during training, so as to verify the feasibility. METHODS： The one-DOF rehabilitation robotic system could be driven to guide the impaired upper-limb to move around the axis reiteratively. The actual movement was mapped into the virtual environment. Three different virtual environments were built with different grades. The patients could follow the guiding ball in the virtual environment to control the other ball, which mapped the motion of the robotic arm. The motion of the upper-limb was shown in graphic on the screen as visual feedback. Meanwhile, potential field of virtual forces was built around the preset routine and force feedback was calculated according to the error between the actual position and the predictive position to indicate and help the participant where to move. Primary experiments were performed with a healthy right-handed female. RESULTS： ①The actual movement was mapped to the virtual motion correctly in the virtual environment and the participant can control the virtual object through the robotic arm. ②While there were errors between the actual position and the predictive position, the virtual environment can provide the participant with force feedback through the robotic arm. CONCLUSION： Virtual environment built by this method can provide implication and help for the subject with visual and force feedback during rehabilitation and this method is promising in rehabilitation with robot.