The use of surface electromyography in dysphagia evaluation

Dysphagic patients usually have a variety of clinical problems such as malnutrition, significant weight loss, and aspiration pneumonia. Dysphagia is a complication commonly caused by strokes, and surface electromyography (sEMG) provides a simple, non-radioactive, and non-invasive method to measure the patterns of muscle activity during swallowing, allowing clinicians to describe the physiology of swallowing behavior. Most previous studies have described swallowing behavior in terms of amplitude and duration. However, there is no objective and precise approach available for the evaluation of swallowing coordination. In order to evaluate swallowing coordination more precisely, a wireless and wearable monitoring device for dysphagia evaluation was designed for the present study in order to measure four muscle groups simultaneously during swallowing. In this context, the variations of the cross-correlation coefficients were defined as the discoordination index, a metric which can effectively reflect the differences between the surface EMG patterns of the bilateral muscle groups. The experimental results of this study show that the discoordination indices for dysphagic patients are significantly larger than those for healthy subjects and that these discoordination indices can be used as an effective means of evaluating the coordination between bilateral swallowing muscles.