A Prospective, Multi-center, Randomized, Controlled Clinical Trial to Evaluate the Effectiveness and Safety of Hydrogen—Oxygen Generator with Nebulizer for Rehabilitation Treatment of Dysfunctions in Discharged Patients Who Are Previously Hospitalized due to 2019 Novel Coronavirus Pneumonia (COVID-19)

INTERVENTION: Test group: The test group will use experimental medical equipment, Such as Hydrogen‐Oxygen Generator with Nebulizer ( Shanghai Asclepius Meditec Co., Ltd.) + basic treatment (The researcher will give the corresponding symptomatic support treatment according to the condition of the subjects);control group:basic treatment (The researcher will give the corresponding symptomatic support treatment according to the condition of the subjects); CONDITION: Rehabilitation Treatment of Dysfunctions in Discharged Patients Who Are Previously Hospitalized due to 2019 Novel Coronavirus Pneumonia (COVID‐19) PRIMARY OUTCOME: Changes in Borg score from baseline at 3 months after the study treatment.;Changes in PSQI score from baseline at 3 months after the study treatment.; SECONDARY OUTCOME: Pulmonary function evaluation;Change in imaging evaluation;Neurological and psychological function indicators;Inflammatory indicators;Usability evaluation of the medical device; INCLUSION CRITERIA: 1)Male and female subjects aged between 18 and 75 years old (inclusive); 2)Subjects previously hospitalized due to COVID‐19, who are recovered and discharged with negative results for COVID‐19 and released from quarantine; 3)Known symptoms of respiratory dysfunctions (such as dyspnea), and / or neurological/psychological dysfunction (such as sleep disorders, anxiety, and depression) and / or somatic dysfunction (such as fatigue); 4)Borg dyspnea or fatigue score before study treatment >= 1 (please refer to Appendi X2: Borg Scale for specific information), and PSQI score >= 2 (please refer to Appendi X3: PSQI Scale for specific information); 5)Subjects who are willing to participate and provided written informed consent form.