Radiofrequency cathode ablation is an effective tool for the treatment of cardiac arrhythmia. Bipolar ablation may provide a more localized lesion and therefore prevent side effects and complications caused by cathode ablation. However, myocardial impedance and heart fat's thickness may have significant influence on the performance of bipolar ablation. In this study, we perform computer simulation to study the influence of myocardial impedance and heart fat's thickness on bipolar and unipolar cathode ablation. Through computer simulation, we obtain and compare the treatment effects under different configurations of cathode ablation. The simulation results are generally consistent with experiment results. Through our simulation, when the fat layer's thickness increases, the bipolar ablation's heating effect decreases, but the final ablation effect is still better than that of unipolar ablation. The ablation performance is improved when myocardial impedance decreases. However, the heating effect of the bipolar configuration is more sensitive to the variation of myocardial impedance and fat layers' thickness compared with that of the unipolar configuration.

Let Fm= (f1,...,fm) be a vector of m logical functions. Let Inv (Fm), the inversion complexity of Fm, be the minimum number of inverters required to realize Fm by a feed-forward network using AND gates, OR gates, and inverters.

A negative gate is a gate which can realize an arbitrary negative function. The problem of synthesizing logical networks, with negative gates only, is important for the design of MOS LSI.

A negative gate is a gate that can realize an arbitrary negative function (or monotone decreasing function) and a positive gate is one that can realize an arbitrary positive function (or monotone increasing function). This paper discusses methods of realizing a given logical function or a given set of logical functions using a minimum number of negative gates alone or using a minimum number of negative and positive gates.