Beyond Sensor Data: Foundation Models of Behavioral Data from Wearables Improve Health Predictions (WBM)

Summary

WBM (Wearable Behavior Model) does not model raw PPG, ECG, or accelerometer waveforms at all. It models 27 already-derived, expert-validated HealthKit quantities — the output of Apple's existing signal-processing algorithms, not their input. The paper's own framing (§1) is explicit: prior Apple/Google work (Abbaspourazad 2024a/b = the Apple PPG+ECG FM and the accel-KD paper; Narayanswamy 2024 = LSM-1) modeled "low-level sensor data (or simple features thereof)"; this paper instead models "higher-level behavioral information ...