Clinical Investigation to Evaluate the Effectiveness and Safety of ECG App

Inclusion Criteria:

1. Patients over 18 years old, regardless of gender;
2. Participants who meet one of the following conditions according to the medical historyin the past 3 months or the ECG during the screening period:
3. Patients with normal sinus rhythm;
4. Patients with persistent or permanent paroxysmal atrial fibrillation or in theonset of paroxysmal atrial fibrillation;
5. Patients with frequent premature beats (more than 5 per minute) or in the onsetof premature beats;
6. Patients who have good compliance, and can cooperate to complete this research byhimself/herself; 4）Patients who volunteer to participate and have signed an informedconsent form.

Exclusion Criteria:

1. Patients using cardiac pacemakers or implantable cardioverter defibrillators (ICD);
2. Patients with atrioventricular block or bundle branch block;
3. Patients with significant sinus arrhythmia, sinus arrest or sick sinus syndrome;
4. Patients with interpolated premature beats, junctional premature beats, or escaperhythms;
5. Patients with atrial tachycardia, atrial flutter, ventricular tachycardia, ventricularflutter, or ventricular fibrillation;
6. Patients with a resting heart rate of slower than 50 beats/minute or faster than 110beats/minute;
7. Patients with atrial fibrillation complicated with premature beats;
8. Patients who are critically ill, making it difficult to make an accurate assessment ofthe effectiveness and safety of the device;
9. Patients who suffer from tremor diseases or chorea, making it difficult to completethe examination quietly;
10. Patients with bullous diseases or large-area skin rashes that are not suitable forbody surface electrode recording;
11. Patients whose skin is allergic to ethanol;
12. Patients with contagious skin diseases;
13. Patients with a history of mental illness or with cognitive impairment;
14. Patients who have participated in other clinical investigations within the past 30days that may affect this investigation; 15） Other conditions that the investigatorsconsider inappropriate for participation in the investigation.