Signal quality
Motion artifacts are the real enemy
Wrist PPG fails most often because of motion, pressure changes, and poor contact. A serious wearable site must explain that problem clearly instead of pretending algorithms can ignore it.
The artifact sources
Motion changes optical path length, sensor pressure, tissue deformation, and ambient leakage. Strap pressure can change perfusion and amplitude without any health change. Temperature can change peripheral circulation. A robust system must model these contexts rather than treat them as noise only.
SciFold approach
SciFold combines optical channels with IMU, pressure, and temperature context. Adaptive filtering, spectral quality metrics, cross-channel agreement, contact checks, and confidence gates determine whether a trend output should be trusted, suppressed, or marked low confidence.
Search value
This page should target keywords like wearable PPG motion artifacts, PPG IMU fusion, and optical heart-rate signal quality. These are realistic long-tail queries where a technical startup can compete.