Progress towards the development of the detop hand prosthesis: A sensorized transradial prosthesis for clinical use

This paper presents the progress towards the development of a sensorized transradial prosthesis designed and developed to be a reliable and easy to maintain prosthesis, aimed at sustaining long-term home studies. The hand builds around a transmission mechanism that implements a semi-independent actuation of the abduction/adduction of the thumb and of the flexion/extension of the index, by means of a single actuator. The new version of the hand includes three bi-axial force sensors in the thumb, index and middle fingers, respectively, allowing to measure the grasping and load forces at the fingertips. The mechanical transmission was revised increasing the grip force to 70 N (maximum single fingertip force) and still guaranteeing fast grasps (closing time ~500 ms). The current version of the prosthesis underwent durability tests and a preclinical evaluation involving one trans-radial amputee.