Usabilidade de um protótipo de prótese transradial com freio magneto-reológico: aspectos funcionais e de satisfação do usuário

Abstract

Introduction: To reduce the functional impact and limitations on the occupational performance of individuals with transradial congenital disabilities, upper limb prostheses (UL) are increasingly used. However, the abandonment rate of devices is still significant and is related to functional, movement, aesthetic, and satisfaction aspects that need to be improved. User satisfaction with the use of assistive technology is important, as it is predictive of the abandonment of prostheses. The pronation/supination movement in prosthetic wrists makes it possible to perform various Activities of Daily Living (ADLs), significantly contributing to users' functionality. To develop devices that offer functionality as close as possible to the human limb, with adequate speed, dexterity energy expenditure, and greater user satisfaction with the technology, the use of intelligent materials, such as Magneto-Rheological Fluid (FMR) in the prosthetic brake It is an innovation that needs to have its usability evaluated in upper limb prostheses. Objective: To verify the usability of a transradial prosthesis with a magnetorheological wrist, for pronation/supination movements, in functional aspects and user satisfaction. Methodology: Experimental study with 4 individuals with unilateral transradial deficiency and 5 healthy individuals. A prototype consisting of a custom socket, a wrist unit with FMR, and a terminal device was tested. Data collection was carried out in three stages. The first involved collecting anthropometric and clinical data from the participants, scanning the volunteers' stumps to create the socket, and printing and adjusting the device. In the second stage, the prototype control ambiance protocol was carried out. The third stage encompassed the training protocol and data collection itself. Dexterity, functional capacity, user satisfaction, and adverse effects from the use of technology were collected and compared, when possible, between groups. To collect the analysis variables, SHAP (Southampton Hand Assessment Procedure) was used; QUEST 2.0 (Assessment of User Satisfaction with Quebec Assistive Technology 2.0); EVA (Visual Analogue Scale); Interview; Point scale and cylinder task. Descriptive statistics, with the calculation of frequency distribution, mean and median was used to characterize SHAP scores, test and cylinder task execution time, user satisfaction with the device, and adverse effects. To compare results related to dexterity, the Mann-Whitney Test was used, considering a significance level of p<0.05. Results: The prototype presented good functionality, enabling the execution of part of the tasks evaluated, in a longer time, compared to healthy individuals. All tasks that required pronation/supination were performed, indicating the use of the braking mechanism for the wrist, using the FMR as promising for use in upper limb prostheses. Some limitations were observed, such as difficulties in activities that required strength and fine dexterity. Improvements related to these aspects, the weight, adjustments, and comfort of the device need to be made. The results provide valuable information for the development of more effective and comfortable upper limb prostheses, aiming to improve the quality of life and functionality of individuals with transradial amputations.