High-Density Wireless Sensing for Expressive Footwear


This effort has resulted in a compact, wireless, low-power sensor card that transmits 8 analog sensor channels (4 are conditioned for pressure measurements), plus bi-directional bend, 2-axis low-G acceleration (tilt), 3-axis high-G acceleration (shock), 3-axis DC magnetic field strength (orientation), angular rate about vertical (spin), height above an active floor, and translational position as derived from a sonar pickup. The current system runs at 20 kbits/sec, and is able to provide full 8-bit state updates across the wireless link (up to 100 meters away) at 50 Hz. We have instrumented a dance sneaker with this device to measure many parameters of foot, sole, and toe expression, continuously broadcasting them to a base-station and PC over a wireless link. Our current demonstrations allow dancers and athletes to directly produce musical streams from their performances. Ongoing work explores the identification of gait characteristics from the sensor data in applications that reach beyond interactive performance, encompassing digital athletic coaching, podiatric therapy, and context extraction for wearable computers.