EIDORS: Electrical Impedance Tomography and Diffuse Optical Tomography Reconstruction Software

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PEEP trial after lung injury (pig)

Methods and Data

Methods and Data

Data were published in:
I. Frerichs, G. Hahn, T. Schröder, G. Hellige Electrical impedance tomography in monitoring experimental lung injury Intensive Care Med. 24:829-836, 1998.

Results

Figure 3 (from Frerichs et al, 1998): Thoracic functional EIT images before (Control) and after the development of artificially induced left lung injury (Lung injury) reflecting the distribution of ventilation in the five animals studied. (The lungs are typically located in the central and ventral parts of the thorax due to the well developed backbone musculature in pigs.) The schematic cross-section of the pig thorax in the left upper corner shows the spatial orientation of the images. Each image is scaled to the individual maximum impedance variation. The scale shows that higher local impedance variation (i.e. higher fluctuation of regional lung volume) is represented in light tones

EIDORS Analysis

1. Download the data and save it to your working directory.
2. Create a FEM model of the pig

   % Create Model $Id: if_lung_injury01.m 3341 2012-07-01 21:26:50Z bgrychtol $
   
   imdl= mk_common_model('c2c2',16);
   % Reverse electrodes to give 'clinical' view (looking toward patient head)
   imdl.fwd_model.electrode =  ...
      imdl.fwd_model.electrode([9:-1:1,16:-1:10]);
   % Use normalized difference imaging
   imdl.fwd_model = mdl_normalize(imdl.fwd_model, 1);
   
   subplot(211);
   show_fem(imdl.fwd_model, [0,1,0]);
   axis equal; axis off
   
   hh=text(-1.15,0,'Right');
   set(hh,'Rotation',90,'HorizontalAlignment','Center');
   hh=text(0,+1.15,'Ventral');
   set(hh,'HorizontalAlignment','Center');
   
   print_convert if_lung_injury01.png 
   
   

   
   Figure: 2D FEM of pig thorax
3. Analyse and show data

   subplot(221);
   for loop1= 1:5;
          
     for loop2 = 1:2;
        if loop2 ==1; fn = sprintf('%d-control.RAW',loop1);
        else          fn = sprintf('%d-injury.RAW',loop1);
        end
   
        prname= sprintf('if_lung_injury02-%d%d.png', loop1,loop2);
   
        dd= eidors_readdata(fn);
   
        img=inv_solve(imdl,mean(dd,2),dd);
        [jnk,fmin] = min(mean(img.elem_data,1)); % find end-inspi
        [jnk,fmax] = max(mean(img.elem_data,1)); % find end-expi
   
        img=inv_solve(imdl,dd(:,fmax), dd(:,fmin));
        show_slices(img);
   
        print_convert(prname,'-density 50');
      end
   end
   
   

   	Pig #1	Pig #2	Pig #3	Pig #4	Pig #5
   Control
   Left Lung Injury

   
   Figure: Images of Tidal Ventilation in Pigs