Patent ID: 8617074
Filing Date: 2013-12-31
Classification: A61B,G01S

Abstract:
1. A method for generating hardness and/or strain information of a wall of a blood vessel, having a substantially circular cross-section, the blood vessel subject to a pressure cycle caused by varying pressure induced by a heartbeat, to determine deformation of the blood vessel wall, the method comprising: positioning at least one signal transmitter outside the blood vessel wall so that emitted signals therefrom encompass a transverse contour of the blood vessel; positioning at least one signal receiver outside the blood vessel wall; using the signal transmitter in a first step and a second step to emit signals (S) towards the blood vessel wall at a different angle in each step with respect to the transmitter's emitting surface viewed in the transverse cross-section of the blood vessel, wherein emitting signals (S) in each of the first step and the second step includes emission of a plurality of signals that encompass the contour of said blood vessel wall while the blood vessel is at various levels of deformation due to heart beat induced internal pressure variations, wherein the deformation of the blood vessel is not caused by external compression; using the signal receiver to receive reflected or partly reflected signals from the blood vessel wall in each step, wherein the received signals result from the signals that have been emitted by said signal transmitter; acquiring strain image data from the received signals in the first step and the second step, wherein in each step a strain image can be acquired for regions where no strain image can be obtained for in another step; and compounding the image data acquired from received signals in the first step and the second step for full reconstruction of the radial and circumferential strain for all regions of the blood vessel wall, and relating the strain of the blood vessel wall to elasticity and hardness parameters of the blood vessel wall; wherein said transmitter and/or said receiver is substantially not moved with respect to the blood vessel wall during the emitting and receiving of said signals; and wherein the emitted signals (S) have a direction that substantially is not aligned with a direction of internal blood pressure induced radial strain in the blood vessel wall.