Clinical Validation of the Electrocardiogram Measurement

Inclusion Criteria: * Willing and able to participate in the study procedures as described in the consent form * Individuals who are 22 years of age and older at time of screening * Able to communicate effectively with and follow instructions from the study staff * Subjects enrolled into Cohort 1 must have no known medical history of AFib and in normal sinus rhythm at the time of screening. * Subjects enrolled into Cohort 2 must have a known diagnosis of persistent or permanent AFib and be in AFib at the time of screening. Exclusion Criteria: * Physical disability that precludes safe and adequate testing * Mental impairment as determined by the Investigator * Pregnant women at the time of the screening visit. * Subjects with any Medical History, Physical exam, vital sign or any other study procedure finding/assessment that in the opinion of the investigator could compromise subject safety during study participation or interfere with the study integrity and/or the accurate assessment of the study objectives. This includes patients with known untreated medical conditions that are considered clinically significant by the Investigator, such as but not limited to significant anemia, important electrolyte imbalance and untreated or uncontrolled thyroid disease. Physical exam limitations include but not limited to open wound(s) on the wrist and forearm where the subject will be wearing the watch. * Any history of wrist surgery with scarring in the area of the sensor location on t…