gms | German Medical Science

In the paper there is presented the method of evaluation of sensitivity of epicardial maps on the changes of parameters of the 3D human thorax model. The epicardial maps are determined on the basis of Body Surface Potential Maps (BSPM’s) in non-invasive way applying the computer simulation method solving the inverse problem of electrocadiology. The 3D human geometrical-conductivity thorax model is referred to the individual patient. For the construction of the model of that individual patient there are applied the CT image data of thorax of three anatomical types - leptosome, average and pyknic taken from the anatomical atlases; they are combined with roentgenograms and external dimensions of a chest of each patient. The specific conductivity data of thorax organs are taken from Rush tables. The calculations were carried out for 9 healthy patients (3 referred to leptosome type, 3 to average, and 3 to pyknic). For each model the respective polygons (referred to that model) were fitted by two techniques: a) manual (more accurate but slower), b) semi-automatic (less accurate but faster). The results are the epicardial maps determined for each case on a basis of BSPM’s for a given instants of ECG. These maps were compared regarding the distribution and values of global extremes for each 3 patients of each of anatomical type for each of 2 techniques (manual and semi-automatic) of fitting the polygons in the model. We can say that the sensitivity of the maps on the changes of the model polygons for the models referred to pyknic type is less than for the models referred to average type and much less than for the models referred to the leptosome type. E.g. for the R instant of ECG the differences between values of global maxima of epicardial maps are about 2%, 4% and 6% respectively. However, each of above case is sufficient in the sense of proper interpretation of respective epicardial maps. This work was supported by MES Research Project No 3T11E 004 29 in years 2006-2007.