Inclusion Criteria:  Adult participants diagnosed with mild to moderate COVID-19 disease without pneumonia. COVID-19 participants with a SpO2 level less or equal to 90 %, exhibiting difficulty breathing, but not intubated. COVID-19 participants with similar pharmacological treatment against COVID-19. 20-85 years old  Exclusion Criteria:  COVID-19 patients with acute respiratory failure requiring urgent intubation COVID-19 patients with impaired consciousness Pregnant woman Patients with metallic implants in the thorax, abdomen, or arms, or with electronic medical devices such as pacemakers Children