Design and Prototyping of an Underactuated Index Finger Exoskeleton

At present, the rehabilitation treatment methods for hand dysfunction caused by stroke are mainly to reconstruct or improve the hand motor function of stroke patients through motor learning. To realize smooth motion without the interference of the underactuated hand exoskeleton system, this paper designs and manufactures an exoskeleton system in which a single motor drives the index finger MCP and PIP to rotate. The simulation results show that the system can realize 0-90° motion of MCP and 0-110° motion of PIP, and the motion is smooth and without interference. The system is prototyping by 3D printing. By testing the prototype, the actual movement range of the prototype is slightly smaller than the design index, and it can achieve the 0-90° movement of the MCP, but the PIP can only achieve the 0-90° movement. Through further research and analysis, it is determined that this phenomenon is caused by unreasonable motion coupling between MCP and PIP, inaccurate axial positioning, and offset of the rotation center of each joint. The system will be used as the basis for follow-up research and will continue to be optimized in combination with the problems shown in the actual wearing, and finally design and manufacture a complete set of underactuated hand exoskeleton systems that can move smoothly without interference.