Desarrollo de una prótesis de mano operada por un actuador mediante señales electromiográficas para aproximar la función de agarre de una mano

Abstract

The objective of this technical project was to develop a hand prosthesis controlled by electromyographic signals, using the gForce 200 sensor as the main actuator, considering a cylindrical grip system. For the design of the prosthesis, through the QFD quality matrix, the necessary parameters were analyzed, focusing on the needs of an adult patient, from these a mechanism was designed that would comply with the appropriate measurements and tolerances. A kinematic, dynamic and structural resistance analysis of the mechanism was developed using MBD software. The MG995 motor was selected based on the required torque, and the appropriate materials were designated, such as PLA filament for 3D printing and acrylic for the links. The processing of electromyographic signals allowed for a rapid response to muscle movements, resulting in smoother and more precise control of the grip. The electronic connection between the sensor and the MG995 servomotor was established by means of the gForce Joint, linked to the ESP32 card, which through the use of sensor libraries, a code was programmed in the Arduino software, taking two signals, both the open position and the closed position, which generate an angular displacement of 55° of the actuator. It was concluded that the prosthesis is suitable for grasping objects of moderate weight, moldable objects, delicate objects, small objects, everyday objects, object that require dynamic movement and objects that need to be held, as long as they do not exceed a maximum weight of 1 kgf and have a coefficient of static friction greater than 0,4. It is recommended that the prosthesis not be used in activities that require fine precision, such as writing with a pen or typing on a computer, or for feeding with a spoon.