Based On The Epicardial Atrial Fibrillation Signal Processing Method Of Standard Measuring Technology Research

Atrial Fibrillation (AF) is a supraventricular tachyarrhythmia characterized by uncoordinated atrial activation with consequent deterioration of atrial mechanical function.As the most common arrthymia in clinical practice (prevalence:0.4%-1%), AF is a great threat for human being, especially for the population of over 80 years old.However, current therapeutic strategies are not perfect for all kinds of AF:Drugs are effective for rate or rhythm control but not for radical cure of AF; Ablation may act as a preferred option for patients with paroxysmal AF. But for patients with persistent AF, the cure rate is not as high as the former. The main reason lies on the fact that the exact mechanisms leading to the induction and perpetuation of AF are still not well understood. To explore the mechanisms of AF thus are greatly meaningful.The technique of epicardial mapping has long played a key role in the research on mechanisms of AF. Epicardial mapping systems always simultaneously measure and record excitation of cardiac cells under mapping sites with multi-electrodes network. The research in this thesis mainly focused on signal processing based on epicardial mapping. I expect to find some methods to extract crucial features from epicardial electrograms, which may be important for searching ectopic drivers or locating reentry paths during AF. Therefore, the methods proposed by this thesis may benefit the research concerning with mechanism of AF and provide clinical practice with some effective references.In this thesis, an offline signal analysis bench was first built for our mapping system. Based on this bench, several processing methods were then designed to overcome noises or artifacts which universally occurred in epicardial electrograms. The third part of this thesis introduced two methods for recognizing cardiac excitation, one based on correlation test, another lying on amplitude threshold.Finally, approaches which can reveal the characteristics of electrograms in time region or concerning with rhythm were proposed in the final section.The results of methods mentioned above have been tested by simulation and animal experiments and approved by several doctors.The researches in this thesis prove that the technique of epicardial mapping was helpful for observing the characteristics of cardiac excitation during AF. Furthermore, researches on epicardial electrograms processing could support further investigation into the mechanisms of AF and clinical therapies.