Overview
ISO/TS 22077-4:2019 - "Health informatics - Medical waveform format - Part 4: Stress test electrocardiography" specifies how to encode stress test ECG and related physiological signals using the Medical waveform Format Encoding Rules (MFER). Published by ISO in 2019, the technical specification defines waveform file structure, tagging/encoding rules (TLV-based), synchronization and packaging of multi-signal data from exercise, pharmacological and cardiopulmonary stress tests. It covers not only the ECG waveform but associated signals such as blood pressure, respiration gas, SpO2 and load information required for clinical interpretation.
Key topics and technical requirements
- MFER application for stress tests: Rules to apply MFER encoding to stress test outputs so files can be exchanged and interpreted consistently.
- File structure and TLV encoding: Waveform frames include header (metadata) and waveform data sections encoded as Tag–Length–Value elements.
- Waveform types: Support for full disclosure waveforms (continuous recording from rest through recovery), intermittent recordings (timed samples), and abstract single-beat waveforms (e.g., averaged beats).
- Time synchronization: Methods to synchronize multiple physiological signals and load events so ECG, blood pressure, SpO2 and respiratory data align correctly.
- Waveform attributes: Lead naming, sampling attributes, frame attributes, filter information and pointer structures for reproducible representation.
- Load and measurement information: Encoding of loading events (warm-up, loading, recovery), amount of load, perceived exertion (Borg scale), R-wave positions, ST-segment recognition and measurement values, beat annotations and interpretations.
- Data preservation guidance: Recommendation to store original, minimally processed waveforms (avoid irreversible compression/filtering) and optionally store processed versions used for clinical interpretation.
Applications and users
ISO/TS 22077-4:2019 is intended for:
- Medical device manufacturers (stress ECG, ergometers, cardiopulmonary testing systems) implementing standardized waveform export.
- Physiological laboratories and clinics that record and share stress test data.
- Health IT and EMR integrators building import/export, archival, and visualization for multi-signal stress test packages.
- Software developers and researchers analyzing stress test ECG, ST changes, and synchronized physiological signals.
- Clinicians and cardiologists who depend on consistent, synchronized multi-signal records for diagnosis of ischemia, arrhythmia and exercise capacity.
Related standards
- ISO/TS 22077-1: MFER encoding rules (base specification)
- ISO/TS 22077-2: Electrocardiography (12‑lead ECG rules)
- ISO/TS 22077-3: Long-term electrocardiography (Holter)
Using ISO/TS 22077-4 helps ensure interoperable, high-fidelity exchange of stress test ECG and associated physiological data across devices and health information systems.