Towards the control of an active hand orthosis for people with Duchenne muscular dystrophy: Design and Validation of a wireless sEMG sleeve

Duchenne Muscular Dystrophy (DMD) is a progressive muscular disease. Active hand orthoses can greatly improve the quality of life of people with DMD. Surface Electromyography (sEMG) is commonly used for the control of active devices. The interfacing between the human and the sensor is regularly done by an adhesive skin interface (sticker). This can cause discomfort, especially during daily use. For forearm sEMG measurements, a sleeve design can solve this problem.

The design presented here aims to make sEMG more comfortable, yet functional for daily use. In order to achieve that, we designed a simple, low-cost sEMG sleeve using a commercial ankle brace. 6 equidistant cuts around the circumference of the sleeve were made in order for the sEMG sensors (Delsys Trigno, Delsys Inc.) to be placed. Those are held in place by a number of 3D printed plastic casings mounted with plastic snap buttons. The buttons are used to make the attachment of the casings fast and easy.

A preliminary evaluation of the sleeve has been carried out with 6 healthy subjects, using a library of 6 and 9 gestures and a simple artificial neural network (ANN) classifier. The performance was evaluated, in terms of classification time, training time and accuracy (offline) and selection time, completion time, completion rate and accuracy (online). The results show that the performance of the sleeve is not significantly different than the adhesive skin interface.

We conclude, that the EMG-sleeve is a better alternative than the current methods for sensor skin interfacing, while having similar performance during a classification task.