ANALYSIS OF ECG BODY SURFACE POTENTIALS

Abstract

Diagnostic utility of the body surface mapping technique, over and above that of the standard 12 lead ECG, has been demonstrated in cardiac disease diagnosis, but the large scale clinic mapping using arrays of 100 or more electrodes on a patient's torso has made widespread use impractical. To develop a practical system, an entire body surface mapping from a much reduced number of electrodes is required. This thesis work has proposed a new mathematical model (complex potential function) to describe the potential distribution on the body surface. By analysing the complex potential function, the Cauchy integral formula technique and the harmonic series technique have been used to accomplish mapping from a reduced number of electrodes. Fortran programs have been written to implement the two techniques. The fit of computed potentials with respect to corresponding experimental ones is specified by three evaluation figures: correlation coefficient, RMS error and error to signal power ratio. Based on ECG data measured by 63 electrodes on 9 subjects, the harmonic series technique has estimated the potential distribution w th an average correlation coefficient of 0.85, RMS error of 410 ,Ltv and error to signal power ratio of 37% for the QRS wave using 10 electrodes placed on the anterior surface.