Wireless body area network for physical-activity classification and fall detection

A body area network constructed by a low-power microcontroller- (MSP430F149) and 2.4-GHz RF transceiver-(nRF24L01) is proposed to record body accelerations from multiple sites. The wireless setups reduce the inconvenience for free-moving due to the line connection between sensors and the central data processing recorder. The body area network was demonstrated useful in our experiments, while the subjects performed a series of scripted physical activity, free-moving, simulated falls and postural changes. In this system, a secure digital memory card was used to store measured acceleration signals in the central unit. The recorded data were processed to classify physical activity of the carrier by a multi-layer fuzzy clustering in a personal computer. Falls were detected by analyzing the changing magnitude of tri-axial accelerations. The proposed system can be applied to measure daily physical activity and detect falls in free-moving patients and the elderly.