RESUMEN
In this study, we investigated a surface electrode stimulation method to support laryngeal elevation in patients with pharyngeal dysphagia, from the viewpoint of functional electric stimulation (FES). Informed consent was obtained from 15 healthy men and 4 patients with pharyngeal dysphagia. Digastric and stylohyoid muscles were stimulated by silver-textile surface electrodes covering the muscle belly. Laryngeal elevation by the electrical stimulation (ES) during liquid (water, 3ml) swallowing movement was measured by digital video camera. The laryngeal elevation trajectory demonstrated a hysteresis loop. The elevation distance of the larynx increased with a rise of stimulus strength. Laryngeal elevation by ES was 76.0% in the normal subjects and 86.6% in patients when measured during liquid swallowing. Applying FES for laryngeal elevation may assist in improving the swallowing reflex.