Desenvolvimento de modelos biomecânicos tridimensionais do membro superior: mão e cotovelo

Abstract

The comprehension of the forces to which the upper members are subjected is essential to improve rehabilitation and chirurgical procedures. Recently, biomechanical models have been developed to reproduce the behavior of tissues and living systems by means ofmathematical equations, such that, by using engineering tools, it is possible to improve our knowledge of the physiological phenomenon. The present work deals with the biomechanical modeling of the human upper member. The geometrical models were constructed using computational technics, to represent the different tissues, to whichboundary conditions and constitutive models were applied. Finite element meshes were generated from the constructed geometries and using the finite element method, the stress and strain fields were obtained. The objective of the present study was to develop amethodology to generate tridimensional models, optimized to be use on numerical simulations of the upper member, with interests on rehabilitation and orthopedics. The methodology consisted on the development, validation and application of biomechanical models of the hand and elbow. To generate the biomechanical models, to different approaches were used, one based on geometrical models obtained from a graphical animation company, and another based on medical images. The models developed on the present work were applied to improve an upper limb orthosis and to analyze the different possible configurations for the insertion of the fixation pins, in order to reduce the supracondylar fracture of the humerus. The models for the hand orthosis and fixation system for the supracondylar fracture of the humerus were validated by experimental values obtained from the literature, while the model for the elbow orthosis was validated with experimental data obtained on the Laboratório de Bioe engenharia da Universidade Federal de Minas Gerais. The results obtained from the numerical simulations of the developed hand orthosis allowed to determine the relation between the traction force on the artificial tendon and the degree of flexion of the index finger. Comparing the numerical results with the experimental and analytical results made its validation. It has been demonstrated that the model for the fixation system for a supracondylar fracture is able to reproduce the mechanical system that occur during the torsion loads on the reduce fracture. Concluding, the methodology used to develop and validate the tridimensional models developed on this work allowed to generate a biomechanical model fro the uppermember.