PREV, Before the pain starts

The anatomical insight that made the solution possible: the four muscles controlling finger movement extend continuously from the fingertips to the forearm. Sensors on the forearm capture the same fatigue signal as sensors on the fingers — without interfering with the instrument or the musician's technique.

PREV is a wearable armband that monitors forearm EMG signals in real time. Before each session, a 30-second rest period captures the individual's baseline amplitude — because fatigue thresholds vary significantly between musicians, making any universal timer useless. During play, the system continuously monitors the signal and alerts the musician via vibration when RMSE reaches 90% of the individual fatigue threshold. Vibration was chosen deliberately: during active performance, ears are on the sound and eyes are on the score. Tactile is the only sensory channel that reaches the player without disrupting the performance.

Testing confirmed the detection logic performed reliably across subjects. The primary constraint was physical: the prototype armband was too heavy and restricted natural arm movement. Next iterations would address this through hardware miniaturisation, a flexible conformable substrate, and a companion app for tracking cumulative fatigue across sessions.