The contribution of the lungs to thoracic impedance measurements: a simulation study based on a high resolution finite difference model.
A high resolution electrical finite difference model of the human thorax based on a 43 slice MRI data set along with lead field theory was used to examine the contribution of the lungs to the total impedance for a typical mid-thoracic 2D EIT eight and sixteen electrode configuration. Regional analysis of the thoracic sources of impedance revealed that the maximum contribution of lungs to the total impedance was approximately 22% for the eight electrode array and 25% for the sixteen electrode array. Analysis of impedance distribution of the lungs using a mid-thoracic application showed that the contribution of impedance of each slice followed closely the volume of the lungs in the given slice. This suggests that the mid-thoracic application gives results reflecting the entire lung. The contributions of the lung impedance for the various electrode positions showed that the eight electrode configuration had a more smooth change between adjacent electrodes compared to the 16 electrode arrangement.
The Bakken Medical Instrumentation and Devices (MIND) Laboratory, Biomedical Engineering Institute, University of Minnesota, 420 Delaware St, MMC 297, Minneapolis, MN 55455, USA.
Fei
F
Yang
Robert P
RP
Patterson
D000388:Air; D001769:Blood; D003198:Computer Simulation; D017097:Electric Impedance; D004566:Electrodes; D006801:Humans; D008168:Lung; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011827:Radiation; D013909:Thorax; D014054:Tomography / Q000379:methods*