Activity
Steps, movement duration and sedentary periods are common outputs, but they depend on manufacturer algorithms and user behaviour. A reproducible feature definition matters more than a consumer wellness score.
Sleep and heart rate
Consumer wearables infer sleep from movement and physiological signals, with device-specific accuracy and missingness. Heart rate and variability have many possible causes. Neither should be interpreted as a cancer-treatment toxicity without separate validation.
Protocol minimum
- Device model, firmware and source fields.
- Feature algorithm and transformation version.
- Quality and missing-data criteria.
- Personal baseline and time window.
- Human-review rule without autonomous treatment advice.