Imaging spatial distribution of high-frequency small vibrations on the heart wall

Abstract

curately measuring the velocity signals on the multiple Absimci-We have developed a novel method for acpoints preset on an ultrasonic beam in the heart wall by tracking the movement of the heart wall. By applying the time-frequency analysis to the resultant velocity signals of the heart wall, we have determined the instantaneous eigen-frequency of the left ventricle (LV) at the end-diastole. From the eigen-frequency, the wall thickness of the LV, and the average radius of the LV, the i n n e r pressure of the LV is noninvasively estimated at the end-diastole using a model of an elastic spherical shell.the mode of the eigen-vibration in the LV. In this reFor this measurement, however, it is necessary to confirm port, therefore, we control the directions of the ultrasonic beams so that the velocity signals are simultaneously measured at the multiple points on the surface of the LV wall. From these data, we estimate the spatial distribution of the eigen-vibration of the LV wall at the end-diastole.