Design of a prototype of a hand bionic prosthesis with independent mobility and three-dimensional wrist rotation controlled by sEMG sensors

Abstract

The present research consists of the mechanical and electronic design of a hand prosthesis that is composed of a parallel robot platform to perform the movement of the wrist, on this platform 3 universal joints will be mounted that will be connected to the base of 3 linear actuators that represent a prismatic joint for the extension and flexion movement of which will be cont rolled by an Arduino Mega type board. The design of the prosthesis consists of a base that represents the palm of the hand joined to the proximal phalanx, which will be attached to the medial phalanx and finally attached to the distal phalanx assembled by means of mechanical couplings that will represent the fingers of a human hand, the mechanism for its movement will be through the medial internal link and proximal internal link to the interior of each finger interconnecting each phalanx and finally connec ted to the terminal link that is attached to the axis of the MG90S servo motor, that will allow the mobility of the links and in turn of the phalanges. Likewise, for the individual mobility of the thumb, a proximal internal link is used inside, 2 servomoto rs for the lateral and contralateral opposition of the thumb. These actuators will be controlled by the same microcontroller mentioned above. For the drive of the motors, EMG sensors are used to capture the user's intention of movement through muscle pulse s of the residual limb, the methodology applied for this design is based on three stages (mechanical stage, electronic stage and the integrative stage). As a result, it is obtained that the design of the prosthesis achieves the independent movements of eac h finger and wrist, also the good communication of the sensors and actuators.