Development of a Multisensory Underactuated Prosthetic Hand With Fully Integrated Electronics

The compliance and manipulability are the crucial properties for prosthetic hands design, especially considering both the usefulness and versatility. This study presents a novel mechatronic design of an underactuated prosthetic hand named HIT-VI hand. It consists of four modular underactuated fingers, one opposite thumb, and a set of multisensory embedded control system. Each modular finger uses one dc motor to drive its two active joints and one passive joint. Due to the use of an underactuated nine-bar mechanism, it can execute anthropomorphic coupled motion and self-adaptive motion. The hand contains 39 distributed force sensors, 10 angular position sensors, 6 current sensors, 1 temperature sensor, and 1 inertial measurement unit (IMU). The multisensory system enables the prosthetic hand to achieve intelligent position/force/current control. The fully integrated mechatronic design makes the prosthetic hand similar to an adult hand in size, weight, and appearance. Based on the kinematics and statics, the stability analysis of the prosthetic hand is carried out. Furthermore, the experiments executing the activities of daily living validate that the proposed hand has a respectable compliance and manipulability.