- By Alex David
- Sat, 12 Jul 2025 11:49 PM (IST)
- Source:JND
Apple, together with USC, has created an AI model that changes the narrative on how we analyse health data from wearables. The study proposes a new model called the Wearable Behaviour Model (WBM)—an AI framework that evaluates an individual’s health through behavioural data such as sleep, movement, and activity. Rather than focusing on effort-intensive and often inaccurate raw data like blood oxygen levels or heart rate, WBM prioritises human behaviour and lifestyle patterns. Initial results indicate that this approach can improve the significance of health-related insights, transforming intervention design and enabling tailored health monitoring.
Let's look into what the model analysis revealed, how the model functions, and its anticipated impact on wearable technology and predictive health analytics.
Why WBM Uses Behaviour Data to Assess Everything
Most health monitoring today relies on sensor-driven metrics: heart rate, oxygen saturation, temperature, etc. While useful, these metrics do not provide information on the person being monitored and their unique situation. These metrics often provide inaccurate information as they are based on one-off noise.
The latest research, “Beyond Sensor Data: Foundation Models of Behavioural Data from Wearables Improve Health Predictions,” proposes that behavioural information such as sleep duration, step count, and weekly activity patterns may correlate better with health outcomes.
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What Is the Wearable Behaviour Model (WBM)?
WBM is an artificial intelligence model that has been developed based on the behavioral data of over 162,000 users It is powered by the Apple Heart and Movement Study (AHMS), which contributed over 2.5 billion hours of wearable data.
Core behavioural metrics employed include:
- Duration of sleep and REM cycles
- Step counts over a day
- Changes in gait and motion
- Weekly activity trends
- Indicators related to heart and mobility functions
In total, 27 behavioural metrics were integrated into four clusters: activity, cardiovascular health, sleep, and mobility.
Testing and Training the AI Model
Researchers evaluated the WBM model on 57 specific health-related tasks, which involved and were not limited to:
- Identifying long-standing conditions such as diabetes or heart disease.
- Tracking short-term health improvements, such as post-infection or injury rehabilitation.
Key Results:
Model | Outperformed Baseline In |
WBM (Behavioural) | 39 out of 47 outcomes |
PPG (Sensor Data) | Comparable in select areas |
WBM + PPG Combined | Highest prediction accuracy |
Although WBM did not exceed the performance of the sensor-only model in every single case, the overall accuracy of health predictions was enhanced when traditional PPG sensor data was incorporated alongside WBM.
Why Behaviour Data Is Important
Behavioural data is relatively more straightforward, more stable over time, less subject to extraneous variability, and more reliable compared to technical noise. Unlike raw sensor outputs, behavioural signals are influenced by lifestyles and contexts, which makes them important for identifying both chronic and acute health changes.
The researchers believe that the model provides:
- More relevant feedback for health providers
- Less chance of errors associated with device use
- Health measurements better reflect actual physical conditions.
Challenges and Their Scope
Even with these notable findings, the research does take into account a few limitations:
Narrow range of population: Data was solely reliant on U.S.-based Apple Watch users and does not account for global lower-income demographics.
Accessibility issues: Premium-grade wearables are a necessity for precise tracking, making it difficult to serve underserved communities.
Preprint status: The research has been published on arXiv, but it has not been subject to peer review.
Conclusions
The introduction of Apple’s AI model shifts the paradigm of health tracking. The Wearable Behaviour Model examines our daily routines and paves the way for tailored, proactive healthcare. The research underlines the notion that behavioural data may not just be an ancillary result of fitness tracking; in fact, it could serve as one of the most dependable predictors of sustained health. Coupled with conventional sensor data, this strategy could underpin tomorrow’s intelligent health monitoring systems.