Desenvolvimento de órtese para auxílio no tratamento de pacientes com perda de mobilidade nas mãos

Abstract

The loss of hand mobility compromises quality of life, driving the development of affordable robotic orthoses for rehabilitation. This work aims to design andconstruct a low-cost, exoskeleton-type electric orthosis to assist in therapy sessions.. The methodology included the kinemat ic study of the fingers as a four-bar mechanism, 3D modeling of the prototype, and experimental validation. The model was validated by comparing the output forces on the phalanges obtained via ANSYS Rigid Dynamics with bench test data. The structure was manufactured using additive manufacturing, with actuation driven by MG995 servomotors and logical processing via an Arduino Uno with a Bluetooth interface. The results of the computational simulations indicated peak retention forces at the distal phalanx ranging between 7.31 N and 7.54 N for the analyzed fingers. Benchtop force retention experiments confirmed the project data, recording a mean force of 7.24 N with a relative error of less than 5%. Under dynamic actuation conditions, active forces were limited to an average of 2.37 N due to structural friction and the adoption of a smooth acceleration profiling in the control code, designed to ensure human biomechanical comfort. In the final assembly, physical restrictions and severe friction required the suppression of modules, operating the prototype stably only on the index and ring fingers. It is concluded that the exoskeleton model was successful in the technical validation of control and forces; however, the ergonomic challenge caused by the thickness and rigidity of the links suggests that future low-cost applications should invest in hybrid orthoses, such as flexible tendon-driven gloves.