Figure 1: ( lef t ) Photograph of a University of Mississippi student-athlete wearing an xPatch device behind the ear under the helmet during a game. (right) Biosensor design and output waveforms. Each sensor measures linear and rotational acceleration about each axis and collects 1 sample each millisecond for 100 milliseconds after the MEMS wake-up function is activated. Each waveform contains the acceleration about x, y and z, and the maximum instantaneous acceleration.