The Whole Atrial Epicardial Mapping Such As System And Its Three-dimensional Potential Map Interpolation Method

A novel whole-atria epicardial mapping system is proposed in this study,which can generate the isopotential map to help understanding the generation aswell as the maintenance of the atrial fibrillation (AF).The isopotential map isthe most straightforward presentation to use contours or constant colors paintingthe region with same potential.Of great practical concern in isopotentialmapping is the trade-off between spatial sampling density and the coverage ofcardiac geometrical model,the limits of which are defined by the finite numberof channels that can be sampled synchronously.A proper interpolation can solvethis problem and get the potential distribution on the whole geometrical model.In the third chapter,such a 3D interpolation method is proposed,which canfinish one interpolating routine on the whole geometrical model (6134 triangles)in 12us.The relative error (RE)of this method on 2 test electrodes isrespectively 18.25% and 16.35% smaller than the B-Spline interpolation.Butthis method has some subtle ambiguities and limitations because it is a linearone.For example,it may cause considerable distortion during activation,whenthere is a strongly non-linear distribution of potential with space across thewavefront.In the latter part of this study,some additional proceedings aredesigned for constraining this kind of distortion.Such a kind of epicardial mapping system is becoming more and morepopular in studying the complex arrhythmias which usually have multiplesources,multiple propagation paths and are time varying.Because the electrodeused in the system is sutured tightly on the epicardial surface,and the voltagevariation on the electrode pads can synchronously reflect the propagation ofexcitation.In the other hand,the regular electrophysiological examinationmethod,such as ECG,torso mapping and etc,are not appropriate for complexarrhythmias studying.Because some of them have not enough spatial resolution,others take too much time to collect useful information to generate a map,or are not suitable for in-vivo mapping.In the last chapter,we bring forward someanimal experiments carried out in Anzheng Hospital,Beijing and ZhongshanHospital,Shanghai.In one of these experiments,the epicardial mapping systemis used in the studying ofvagal AF by using the Scherlag's experiment protocol,which is constantly stimulating on the IVC-LA fat pad located between theinferior vena cava and the inferior surface of the left atrium.In this experiment,several onsets of AF are observed.The isopential mapping of these AFsindicates the same conclusion described by Scherlag,which is theelectrophysiological characteristics of myocardium might have been changedduring the sustaining of vagal AF.This experiment can prove the feasibility ofour epicardial mapping system.