Tissue deformation in ultrasound (US) imaging leads to geometrical errors when measuring tissues due to the pressure exerted by probes. Such deformation has an even larger effect on 3D US volumes as the correct compounding is limited by the inconsistent location and geometry. This work proposes a patient-specified stiffness-based method to correct the tissue deformations in robotic 3D US acquisitions. To obtain the patient-specified model, robotic palpation is performed at sampling positions on the tissue. The contact force, US images and the probe poses of the palpation procedure are recorded. The contact force and the probe poses are used to estimate the nonlinear tissue stiffness. The images are fed to an optical flow algorithm to compute the pixel displacement. Then the pixel-wise tissue deformation under different forces is characterized by a coupled quadratic regression. To correct the deformation at unseen positions on the trajectory for building 3D volumes, an interpolation is performed based on the stiffness values computed at the sampling positions. With the stiffness and recorded force, the tissue displacement could be corrected. The method was validated on two blood vessel phantoms with different stiffness. The results demonstrate that the method can effectively correct the force-induced deformation and finally generate 3D tissue geometries
翻译:超声(US)成像中的组织变形因探测器的压力而测量组织时导致几何误差。这种变形对3D美国体积的影响更大,因为正确的化合物受位置和几何不一致的限制,因此对3D美国体积的影响更大。 这项工作提出了一种由病人指定的僵硬性法, 以纠正机器人3D美国组装中的组织变形。 为了获得病人指定的模型, 在组织上的取样位置上进行机器人色化。 记录了接触力、 美国图像和探测器对触感器的构成。 接触力和探测器用来估计非线性组织变异性。 将图像输入光学流算法, 以解像素移位。 然后, 不同力量下的像素组织变形法的特征是结合的四重回归。 为了纠正3D体积的轨迹上的隐形变形, 根据取样位置所计算的硬性值进行内分解。 由于僵硬性和记录力, 组织变形法可以被校正。 两种血容器的变形方法最终被校正。