Design and realization of a portable data logger for physiological sensing [GSR]

A microcontroller-based data logger has been designed, prototyped, and field-tested for recording galvanic skin response data and relaying them to a computer for physiological analysis. Focusing on system design issues concerning battery-driven ambulatory applications, this paper presents a special data compression algorithm based on relative encoding to optimize memory utilization and reduce data transfer time. Data flow coordination and timing control are enabled by a PIC microcontroller. A handheld prototype measuring 180/spl times/90/spl times/30 mm was built and tested for ease of use, safety, and reliability.