Zio® monitor (DFG0001)

The Zio monitor is a prescription-only, single-use wearable ECG patch that continuously records heart rhythm data for up to 14 days. It is indicated for ambulatory patients 18 years and older who may be asymptomatic or experiencing transient cardiac symptoms such as palpitations, dizziness, or syncope. The device stores data locally without real-time wireless transmission; after wear, data is returned to iRhythm for analysis by the ZEUS System and review by qualified cardiac technicians.

The Zio monitor is substantially identical to its predicate in design: single-channel ECG recording, 10g weight, polycarbonate housing with hydrocolloid adhesive, 21-day memory capacity, and continuous recording format. Minor differences from the reference device (Zio AT) include the removal of wireless transmission capability and auto-trigger functionality—the subject device relies only on patient-triggered event marking via button press. The device operates at 200 Hz sampling rate with 15.5-bit resolution and incorporates a single lithium manganese dioxide coin cell battery.

Conformance to IEC 60601-1 (medical electrical equipment safety), IEC 60601-1-11 (home healthcare), IEC 60601-1-2 (electromagnetic compatibility), IEC 60601-1-6 (usability), IEC 60601-2-47 (ambulatory ECG systems), ISO 10993 series (biocompatibility), ISO 14971 (risk management), IEC 62366-1 (usability engineering), and IEC 62304 (software lifecycle). Testing included system performance, biocompatibility, firmware verification, electrical safety/EMC, human factors, and IR sensitivity analysis.

The subject device shares the same intended use, indications, classification, and fundamental operating principle as the predicate—both are non-wireless, single-channel, patient-worn ECG monitors with identical adhesive systems, battery types, ECG specifications, and performance characteristics. The removal of wireless transmission and auto-trigger functions from the reference device (Zio AT) to create the subject device represents a simplification rather than a new feature, reducing rather than increasing safety risks. Nonclinical testing demonstrated equivalent performance and conformance to established standards, with IR sensitivity analysis confirming analyzable time equivalence between subject and reference devices.