Patent ID: 6277074
Filing Date: 2001-08-21
Classification: A61B

Abstract:
A method for motion estimation within biological tissue comprising:(a) acoustically coupling a transducer to a target biological tissue;(b) emitting at least one ultrasonic signal from said transducer into said target tissue along a scan plane;(c) collecting ultrasonic energy back-scattered by at least said target biological tissue;(d) storing said back-scattered ultrasonic energy collected in step (c) as a first data set;(e) compressing said target biological tissue in a substantially axial direction;(f) emitting at least one ultrasonic signal from said transducer into said target tissue along said scan plane while substantially maintaining said compression;(g) collecting ultrasonic energy back-scattered by at least said target biological tissue under said compression;(h) storing said back-scattered ultrasonic energy collected in step (g) as a second data set;(i) warping one of said first and second data sets to account for said compression to form a warped data set;(j) cross-correlating said warped data set with the unwarped one of said first and said second data sets to obtain a fine scale displacement of said target biological-tissue from the displacement estimated by said warping.(k) summing said fine scale displacement and said warped data set to obtain a total axial displacement;(l) taking a gradient of said total axial displacement; and(m) forming a strain image from said gradient of said total axial displacement.