The determination of the bidomain conductivity values of heart tissue

A method for determining the bidomain conductivity values was developed. The study was due to the different sets of conductivity values reported in the literature, each producing significantly different bidomain simulation results.The method involves mapping the propagation of the electrical activation of cardiac tissue, initiated by point stimulation, via extracellular electrodes. A time-dependent bidomain model is used to simulate the electrical phenomena. The optimum set of conductivity values is achieved by minimising the difference between the bidomain model output and the measured extracellular potential, by means of inverse techniques in parameter estimation, such as leastsquares (LS) and singular value decomposition (SVD). The method takes a different approach to the conventional four-electrode technique, as it does not require the small electrode separation needed to separate the extracellular current from the intracellular.