Detection of swallowing disorders with a multiple-channel surface electromyography sensor sheet

Background/purpose: A sensor sheet comprising multiple electromyography electrodes that can be used to measure a series of multiple muscle activities related to swallowing was recently developed. In this study, we aimed to evaluate its utility in detecting swallowing disorders with a new method for the identification of muscle activity. Materials and methods: All participants were evaluated by using the repetitive saliva swallowing test and modified water swallowing test and were classified accordingly into participants with (n = 21; mean age, 81.6 [standard deviation, 10.1] years) and those without (n = 41; mean age, 70.0 [8.4] years) dysphagia. The sheet contains four pairs of electrodes, and surface electromyography (sEMG) was performed on the suprahyoid (position A: upper front of the suprahyoid muscles; position B: bottom rear of the suprahyoid muscles) and infrahyoid (position C: above the infrahyoid muscles; position D: beneath the infrahyoid muscles) muscles while the participants swallowed liquid, thickened water, paste, and jelly. The sEMG findings, including the duration of swallowing waveforms and the delay in swallowing onset from position A to positions B, C, and D, were compared between the groups. Results: The duration of muscle activity differed between the groups in the infrahyoid muscles when jelly (Mann–Whitney U test; position C, P = 0.007 and position D, P = 0.018) and thickened water (position C, P = 0.033) were swallowed. Conclusion: Our study demonstrates the utility of a novel sensor sheet developed for detecting swallowing disorders by using visual methods for identification of muscle activity.