The Establishment Of The Extracellular Mapping System And Its Preliminary Application Of The Atrioventricular Junction,

The application of extracellular potential mapping(EPM) requires developing EPM system methodology and instrumentation. Studies of this dissertation includes engineering realization of a high performance 45 lead EPMS, theretical analysis of extracellular potential.The system can be switched to DC coupling mode,which enables electrograms to be integrated accurately. The multichannel electrogram amplifiers posses low noise, low power consumption, high CMRR, high input impedance and high uniformity. The software realized with OOP techniques provides and confirmes analysis procedures for EPM and high resolution electrograms.It can be compatible with any other lead system. A circulated color encoding method is proposed for imaging the extracellular potential distribution on any potential scale. Isochrone maps are marked with arrows denoting the directions of wave propagation, and the length of arrow represents the velocity of propagation.Results of a series of experiments such as: saline tank test and epicardiol mapping demonstrate that the EPMS is suitable for cardiac activiting mapping.The pattern of atrioventricular junction activation in isolated rabbit hearts was studied by using EPMS. A rectanglar electrode(diameter 1.2cm) containing 45 unipolar electrodes(silver wires,diameter 0.3mm)arranged in a 9 × 5 array(interelectrode distance 1mm) was used. Both antegrade and retrograde spreed of excitation were mapped.During atrial pacing, AV node had a dual input,one from a posterior direction on the crista terminalis and one from the lower septum. The major input during antegrade conduction was from the crista terminalis. The output during retrograde...