Development of a swallowing electrical stimulation system for treatment of dysphagia in stroke patients

A swallowing electrical stimulation system (SESS) with four-channel electrotherapy modules was designed specifically for the treatment of swallowing disorders. The present study provides clinical experimental evidence that swallowing function can be restored by strengthening the masseter and digastric muscles with SESS. Eleven stroke patients (9 males, 2 females) were included in the study. Subjects were compared with themselves before and after SESS intervention. Electrical stimulation was applied to the skin above the masseter and digastric muscles in all subjects. Training consisted of 12 sessions of swallowing training, during which the intensity of the muscles of both the sound and affected side was displayed on the SESS screen. The myoelectrical activity of the muscles was recorded before and after the SESS intervention. The results indicated that 8 of the 11 subjects showed significant gains in myoelectrical activity of the muscles following SESS. Improvements in swallowing function were characterized by changes in electromyographic activity relative to the baseline recording and total time spent in each swallowing activity. These observations show the beneficial effects of SESS on the masseter and digastric muscles with the goal of improving swallow function. The subjects showed increased electromyographic activity and a reduction in total time spent in each swallowing activity. These results indicate that restoring swallowing function by strengthening muscles via SESS facilitates improvement in the treatment of dysphagia.