Prótese mioelétrica de baixo custo para membro superior : desenvolvimento e avaliação do desempenho funcional

Abstract

Introduction and Justification: Upper-limb amputations often have a significant impact on functionality and quality of life, restricting occupational, leisure, and daily activities. During rehabilitation, amputees' main expectations include the use of a prosthesis, particularly regarding its functionality and appearance. The prostheses provided by the Brazilian Unified Health System are predominantly mechanical and have limited functionality. However, myoelectric prostheses are available and are capable of restoring pinch movements through electromyographic signals detected by electrodes; nevertheless, their high-cost limits access, and they are not routinely provided by the SUS. Objectives: To develop and evaluate the functionality of a low-cost electromechanical pinch prosthesis with integrated electromyographic (EMG) sensors for activation. Methods: The study was conducted in three stages: Stage 1 - prosthesis development; Stage 2 - pilot testing with six non-amputee participants (NAG) and two amputee participants (AG); and Stage 3 - clinical testing with 30 non-amputee participants. Functionality and satisfaction were assessed using the Pick and Place (PAP) test and the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST). Results: Article 1 -The developed prosthesis demonstrated satisfactory functional performance in the proposed tasks involving grasping, reaching, and transporting objects, and proved to be a safe and stable device during use. Article 2- In the clinical testing stage, a significant reduction in execution time was observed across trials (p < 0.001), indicating progressive improvement in task performance. Comparison between the first and twentieth trials showed a reduction of 2.71 seconds for the right limb (p = 0.004) and 2.83 seconds for the left limb (p = 0.002). A significant difference in execution time was observed among the objects (p < 0.001), with the bottle requiring the longest mean manipulation time. No significant differences were identified according to limb dominance (p = 0.441) or handgrip strength. Body mass index (BMI) showed a positive association with execution time (p = 0.024), whereas left upper-limb circumference at the E10 measurement point showed a negative association (p = 0.016). Conclusion: The results demonstrate the feasibility of developing a low-cost myoelectric prosthesis, with "low cost" defined in comparative terms relative to commercially available myoelectric prostheses, whose high cost may represent a barrier to access to assistive technology. The device demonstrated functional performance, safety, and stability during grasping, reaching, and object transport tasks. Performance improved progressively with task repetition and was influenced by object characteristics and certain anthropometric characteristics of the participants. These findings reinforce the importance of training and individual adaptation, as well as the influence of individual characteristics and object properties on functional performance. Thus, the developed prosthesis represents a promising alternative for expanding access to functional assistive technologies within the Brazilian Unified Health System (Sistema Único de Saúde - SUS), although further studies are needed to assess its costs, durability, and clinical applicability in the amputee population. [resumo fornecido pelo autor] Palavra-chave