Establishment And Application Of Coronary Resistance System In Animal Experiment And Clinical Research

PART ONE Establishment of the Evaluating System of the Cor o nary Arterial Resistance Object ive : T o establish the resis t ance evaluatin g system of c o ronary artery based on a personal com puter (PC). Methods and r e sults: Intra-vascular ultrasound (IVUS) im ages, intracoronary Doppler signals, intracoronary pressure signals in the m i ddle segm ent of left anterior descending artery (LAD) were acquired using intracoronary ultrasound im aging catheter, Doppler flow wire and pressure wi re s e para tely. E C G signals were record ed sim u ltaneously. The im ages and signals were res p ectiv ely sa mpled into a PC using the im age and signal acquisition cards and the corresponding software. A m o dified active contour m odel was used to estim a te the lum e n area of the co ronary artery from IVUS im ages, and a m e thod integrating m o rphology and dynam i c programming were applied to extra c t the varia tion of velo city f r o m the Doppler spec tr um . W ith the elec troc ardi og raph as the synchronization, variation of blood volum e in a cardiac cycle was calculated as velocity m i nus area. Th e curve of volum e/pressure in a card iac cycle was drived from the curve of volum e and pressu re. Hereby, the resistance param e ters for the coronary artery in frequency dom a in we re com puted as pressure divided by volum e using the Fourier series of blood volum e and pressure. Conclusions : The curv e of volume/pres sure in a cardiac cycle and resis t ance param e ters for coronary circulation we re established successfully through the software of PC system . Key w o rds : coronary artery;IVUS;active cont our detection;Doppler;pressure;resistance;harm onic;curve...