Transformace 12 svodového EKG do VKG

Abstract

This thesis deals with transformations from electrocardiographic (ECG) to vectorcardiographic (VCG) leads. VCG provides a better sensitivity for example for detection of the myocardial infarction, ischemia and hypertrophy. But in the clinical practice, measurement of the VCG is not usually used because it requires additional electrodes placed on patient‘s body. Instead, mathematical transformations are used for deriving VCG from 12-leads ECG. In this work, quasi-orthogonal method by Kors, inverse Dower method, Kors regression-based method and linear regression-based methods for deriving P wave (PLSV) and QRS complex (QLSV) are implemented and compared. Two programs were created in this work. The first program includes graphical user interface and can be used for viewing original and derived VCG records. The second one is used for comparison of the individual transformations and statistical analysis. Transformation methods were compared for the data from the PTB database and their accuracy were evaluated by Mean Squared Error (MSE) and correlation coefficient (R) between derived and directly measured Frank leads. Based on the statistical analysis, the Kors regression-based method is significantly more precise for derivation of the X and Y leads than the others. For lead Z there are not statistically significant differences in medians betwen the Kors regression-based method and other regression-based methods.