Development of a pneumatic robotic system for bilateral upper limb interactive training with variable resistance

This paper presents the development of a pneumatic robotic system for bilateral upper limb interactive training with variable resistance (resistance means force resistance here). This device can be adjusted to certain angle of inclination to enlarge its workspace. A motion module is designed to direct linear movement of two handles in parallel. The handle can be actively driven by human users with variable resistance that is realized through a pneumatic system. The pneumatic system mainly consists of pneumatic cylinders, throttle valves and electromagnetic valves, which allows for the resistance control of each motion module. Three work modes, including asynchronous, synchronous and independent movements, are implemented. A game was also developed to guide human users to do task-oriented bilateral training. Quantitative experiments were conducted in a lab environment to evaluate the variable resistance performance of the robotic system. Qualitative feedbacks were also obtained from each participant. Results show that the robotic system is able to deliver appropriate bilateral training with different levels of resistance. The majority of the participants gave a positive feedback in using this device.