Simultaneous display of lung ventilation and perfusion on a real-time EIT system

EIT images obtained from the human trunk contain changes originating from the lungs, heart and gastro-intestinal tract. In some cases these changes may be spatially separable but in others they can only be separated by temporal filtering. For example, changes relating to both the cardiac and respiratory cycles are present in the lungs. We show that on-line temporal filtering of the images from a 25 frames per second Electrical Impedance Tomography system can be used to produce both cardiac (perfusion) and respiratory (ventilation) images from a single input data stream.