Patent ID: 8187188
Filing Date: 2012-05-29
Classification: A61B,G01S

Abstract:
1. An image processing apparatus comprising: a carotid artery wall estimation unit that acquires ultrasound B-mode images of consecutive frames to estimate a carotid artery wall at a carotid artery minor axis cross section included in an ultrasound B-mode image of a predetermined frame; and a heart rate variability tracking unit that approximates, by the following Equation (1), a template image, which is prepared by representing the ultrasound B-mode image of the predetermined frame in polar coordinates and includes the estimated carotid artery wall and surrounding tissues of the carotid artery wall, to an image, which is prepared by representing each ultrasound B-mode image of the other frames in polar coordinates and determines the amount of displacement of the inner surface of the carotid artery wall according to the following Equation (2) or (3) so as to minimize a square error, which is expressed by the following Equation (4) or (5), thereby acquiring a time change of the carotid artery wall, wherein r denotes the distance from the center of the carotid artery, θ denotes the direction and is no less than 0 and no more than 2π, t denotes a frame number, d(r) denotes the amount of displacement of the carotid artery and the surrounding tissues, r