Force-Sensitive Prosthetic Hand with 3-axis Magnetic Force Sensors

In this paper, we investigate the use of 3-dimensional (3D) force sensors in a prosthetic hand. 3D force sensing in prostheses can be used to incorporate intelligent grasping capabilities, allowing the hand to automatically adjust its grasp or release an object. This can significantly decrease the burden on the user and increase functionality of the prosthesis. Coupled with an underactuated hand, this opens up possibilities for highly functional, affordable prosthetic hands. In this work, we present our design of 3D magnetic force sensors that are embedded within the fingers of an open-source, 3D printable underactuated hand. We implement a simple control scheme using both shear and normal force readings to automate grasp release. Finally, we combine this force control with EMG grasp detection for a series of pick-and-place tasks. Preliminary results suggest that intelligent grasp control imposes less of a burden on the user than a completely EMG-based grasp control.