DEVELOPMENT OF AN INTRAVASCULAR IMPEDANCE CATHETER FOR DETECTION OF FATTY LESIONS IN ARTERIES

Recent studies show that the presence of fatty lesions in the atherosc lerotic vessel wall is a risk factor far acute occlusion of blood vess els, Although fat has a high electrical resistivity, existing impedanc e catheter systems cannot be used for detection of these lesions becau se artifacts owing to impedance variations in the extravascular surrou ndings have a major and irretraceable effect on the measurement, Stand ard algorithms used in attempt to compensate for these artifacts suffe r from severe instability problems, We defined design guidelines to be met by a new impedance catheter system in order to make a robust reco nstruction algorithm possible and have built an experimental in travas cular impedance catheter (IIC) system according to these guidelines, u sing a normalized differential measurement procedure, With this IIC, w e performed experiments on human iliac arteries from the section ward (fixed specimens), showing that plastic models of arterial fatty lesio ns (8 mm(3)) can be detected reliably.