Figure 3From: Prototype development of an electrical impedance based simultaneous respiratory and cardiac monitoring system for gated radiotherapy Observed signals at (a) the input and output of the current injector, (b) the input and output of the bandpass filter (BPF) during inhalation and exhalation, and (c) the output of the low-pass filter (LPF) and the output of the respiratory monitoring circuit. The subject was a 172-cm, 75-kg, 32-year-old male.Back to article page