Characterization and Adjustment Model of the Cricopharyngeal Muscle Potential from Surface Electromyographic Signals in the Swallowing Process

Parkinson’s disease is a neurodegenerative disorder that can cause denervation in the pharyngeal muscles such as the cricopharyngeus and alterations in the neuronal signal transmission, which causes motor alteration during the swallowing process known as dysphagia. This article seeks to characterize the behavior of this muscle through physical simulation and surface electromyography during the swallowing process. For this, the acquisition of electromyographic signals was carried out in healthy subjects in the neck at the level of C5. Analog and digital conditioning were implemented to reduce artifacts and place the signal in the bandwidth of interest. Additionally, the characterization of the signals was carried out to implement a multiphysics simulation to obtain the potential distribution in the volume conductor. The fundamental frequency of the electromyographic signal was found to be 50 Hz, which allowed establishing the frequency value of the electrical properties of the tissues involved in the model. The cricopharyngeus muscle was modeled as a bioelectric source using the cable equation and the Laplace equation to find the potential distribution in the volume conductor. In the model, a voltage reduction from the source to the surface was evidenced, thus, an equivalence between the potential amplitude of the cricopharyngeal muscle of the implemented model and the potentials recorded by invasive electromyography reported in the literature was found. This result shows the feasibility of implementing similar models in studies that seek to evaluate by surface electromyographic and the state of specific muscle areas as new approaches to support the diagnosis and treatment of pathologies.