Electrotactile Feedback for FES-Assisted Swimming

Abstract

Functional electrical stimulation (FES) can be used to support walking and cycling in spinal cord injured individuals. In the current contribution, we present a new method that, for the first time, enables FES-supported swimming in paraplegics. The proposed setup includes a waterproof stimulator, cables, and electrodes. In preliminary experiments, flexion and extension movements of the knee could be generated to support the propulsion during crawling. A synchronization of the voluntary arm and leg movements showed to have a stabilizing effect on the body position of the swimmer in the water, especially on the roll angle. To enable such a synchronized swimming, an electrotactile feedback algorithm was developed that informs the swimmer about the leg movement by a stimulation of sensory unimpaired regions at the back of the subject at a sensory level. The new setup and methods are currently being tested during the STIMSWIM pilot study with paraplegics. In first preliminary results, an improvement of swimming velocity compared to non FES-assisted swimming was observed in the two first subjects.