This study is a pilot study to prepare clinical trials to evaluate the safety and effectiveness of 4-channel electric stimulation therapy devices as a newly developed function for the treatment of dysphagia disorders.

The purpose of this study is to investigate the difference in effect by the electric stimulation method and to obtain the values such as mean, standard deviation and so on, and to determine the number of subjects to be studied for clinical trials of validation permission in the future.

• Design: Prospective study
• Inclusion criteria of patient group: who has a dysphagia symptom and confirmed by video-fluoroscopic swallowing study
• Intervention: Participants are divided into two group and applied electrical stimulation by a "Synchronized Electrical Stimulation Device(SESD)" in different protocol
• Main outcome measures: Videofluoroscopic Dysphagia Scale (VDS), Penetration aspiration scale (PAS), Measured by kinematic metaphysical analysis. The dietary status of the subjects was evaluated by the Functional Oral Intake Scale (FOIS), and the M.D Anderson dysphagia inventory was used to measure the diet-related quality of life. The Likert scale is used to evaluate the satisfaction with the application of the electric stimulation therapy device of the study subjects.
• Secondary outcome measures: Verifying the safety of functional electric stimulation therapy device for dysphagia, measuring the effect on Tongue Strength through IOPI, the effect on changes in body composition through Bioelectrical Impedance Analysis (BIA; InBody S10, InBody, Inc.), and whether there is a significant change in actual patient intake and nutritional status through oral intake survey and MNA-SF measure. An exploratory comparison of intervention effects over time between 2-week and 4-week interventions.

Inclusion Criteria:

• Patients with oropharyngeal dysphagia confirmed by video fluoroscopy
• Patients with oropharyngeal dysphagia due to central nervous system disease who clinically require application of an electrical stimulation treatment device for dysphagia
• Patients aged between 19 and under 90 years of age regardless of gender
• Those who voluntarily consent to the clinical trial and can visit for the next observation
• Patients with dysphagia within 6 months (including patients with dysphagia due to stroke, traumatic brain injury, cervical spine injury, etc.)

Exclusion Criteria:

• In case of refusal of inspection
• Who do not agree
• When instructions cannot be performed due to mental illness, etc.
• Those who have dysphagia due to respiratory failure, cervical spine surgery, head and neck surgery, and chemotherapy and radiation treatment of the neck
• Pregnant and lactating women
• Pre-interview is conducted only with women of childbearing age to determine whether they are pregnant or lactating. If pregnancy is confirmed during the pre-interview, it is excluded from the test.
• Patients who cannot apply electrical stimulation therapy due to allergies or hypersensitivity reactions
• Others who have comorbidities (e.g., malignant tumors, severe renal/liver/lung diseases, blood clotting abnormalities, etc.) that are inappropriate for participation in clinical trials as judged by the researcher
• Persons with pacemakers and other internal electrical stimulators
• Those who are participating in other clinical trials at the time of screening
• Those who are judged by other researchers to be inappropriate for this clinical trial