Hand rehabilitation device for extension, opposition and reposition

In this paper, the research focused on the development of a hand rehabilitation device which could perform extension, opposition and reposition movements. Firstly, the anatomy of the hand is analyzed and studied to understand where the problem resides; since the mechanism will be applied to post-stroke patients, it is necessary to comprehend the structure and the articulations of the hand, the muscles involved in the mentioned movements and how a healthy hand works. Then, the causes of the problem are studied, what are the consequences on the hand and how to solve every issue. Brunnström Approach is taken as reference for the rehabilitation therapy steps. After the performance target is defined and which function has the priority, a brief research on the state of the art is made. Six different devices are analyzed, taking into account their strengths and weaknesses, evaluating them and trying to find possible lacks to solve. An evaluation of possible solutions is done, in order to find the optimal solution for the problem. Various types of actuation and structure of the mechanism are considered. Defined which are the best choices between the ones proposed, the next step is to design a first prototype with the purpose of bringing together the solutions selected. The CAD used is PTC Creo Parametric. Once the first prototype was designed, it was partially printed with 3D technique (additive manufacturing) and tested; tests were made on the actuation and on the device to evaluated its efficacy. The results are visible in this paper. Finally, a conclusion is discussed with a short resume of the experiments made and the results obtained. Furthermore, remaining problems and future works are analyzed and debated.