In this simulation study, we used an anatomical computer model of the human ventricles to simulate body surface potentials and magnetic field for 10 single preexcitation sites and 8 pairs of preexcitation sites positioned on the epicardial surface along the atrio-ventricular ring. We demonstrated that electrocardiographic and magnetocardiographic inverse solutions using a pair of equivalent dipoles could be employed in localising dual accessory pathways. Average localisation errors were in the range of 5 to 21 mm and 3 mm to 20 mm, respectively, when body surface potentials and magnetic field were used. Additionally, we have investigated the influence of random lead displacements and limited lead selection on localisation results.
In this paper a concept of finite impulse response (FIR) narrow band-stop (notch) filter with non-zero initial conditions, based on infinite impulse response (IIR) prototype filter, is proposed. The filter described in this paper is used to suppress power line noise from ECG signals. In order to reduce the transient response of the proposed FIR notch filter, optimal initial conditions for the filter have been determined. The algorithm for finding the length of the initial conditions vector is presented. The proposed values of the length of initial conditions vector, for several ECG signals and interfering frequencies, are calculated. The proposed filters are tested using various ECG signals. Computer simulations demonstrate that the proposed FIR filters outperform traditional FIR filters with initial conditions set to zero.