Non-invasive assessment of swallowing using flexible high-density electromyography arrays

Swallowing is a vital function that serves to safely transport food and fluid to the stomach, while simultaneously protecting our airways. Evaluation of swallowing is important for the diagnosis and rehabilitation of individuals with dysphagia, a disorder of swallowing. Flexible high-density surface electromyography (HD sEMG) arrays were designed and fabricated to span the floor of mouth and neck muscles. These arrays were applied on 6 healthy participants over duplicate recording sessions. During each recording session, participants performed three different swallowing motor tasks. The HD sEMG signals were filtered and tasks extracted. For each task, the RMS amplitude was computed, visualized, and compared. Dynamic motor coordination was evident in the filtered signals traces, with different electrode locations showing unique temporal activations. The 2D topographical maps allowed the location of different RMS intensities to be visualized, revealing qualitatively similar patterns across participants and tasks. These motor task trends were also seen within RMS quantifications. The RMS metric across all participants identified significant differences between non-effortful 3 ml and effortful 3 ml swallow tasks (
$p=0.006$
) and there was a minimal variation of
$3.1\pm 1.9\ \mu\mathrm{V}$
RMS for repeated recording sessions by each participant. The HD-sEMG array successfully recorded differences in muscle activations during swallowing and was able to discern between two different motor tasks. The arrays offers a spatially detailed non-invasive assessment of the neuromuscular performance of swallowing. Clinical Relevance— The utility of HD-sEMG arrays for evaluation of the muscles involved in swallowing could enable diagnosis and rehabilitation of individuals with dysphagia.