A microcontroller-based data logger for physiological sensing

The design and implementation of a microcontroller-based data logger for recording physiological data is presented. The device is designed to receive galvanic skin response (GSR) data from a commercial GSR instrument, store them on its on-board memory, and relay them later to a computer via the serial port. The focus of the design is on portability and low power consumption for battery-driven ambulatory applications. A special data compression algorithm is developed to optimize the on-board memory usage and reduce the data transfer time to a computer. A PIC microcontroller is used as the central control unit for the data flow coordination. The data logger prototype measures 18×9×3 cm, and can be readily miniaturized using SMT or hybrid techniques.