All electrical and real-time ECG, respiration, airflow, and skin conductance monitoring system

In this paper, we propose a low-cost and real-time multiple physiological parameter monitoring system that measures ECG, respiration, airflow and skin conductance by using an all-electrical method. Skin conductance is chosen to evaluate the activity within the sympathetic axis of the autonomic nervous system. Bio-impedance (BI) and resistance measurement technique using DC servo loop are employed to achieve all-electrical measurement. The system was implemented on printed-circuit-board (PCB) with off-the-shelf components and the total cost of the components is less than a dollar. Measurement results show that ECG, respiration, airflow and skin conductance can be clearly measured simultaneously without interference.