Comparison among low-cost portable systems for thoracic impedance plethysmography
Impedance plethysmography is a technique which allows the monitoring of respiratory activity through the measurement of variations in the trans-thoracic impedance. Provided the measurement system has enough sensitivity, the same technique can also detect heartbeats, thus adding cardiac activity monitoring capabilities. In this paper, a comparison is performed between 2-electrode and 4-electrode systems, considering both volt-amperometric and AC-bridge solutions.