Freehand 3D Ultrasound Calibration Based on Two-Layer Z-Fiducial Phantom
Spatial calibration is a key technique in Freehand 3D Ultrasound. In this article, a two-layer Z-fiducial phantom with one “Z” shaped fiducial in each layer is used to perform spatial calibration. After freehand scanning above the phantom, the intersections of the scan plane and Z-fiducial plane in B-scans are segmented, and the calibration transformation matrix between the coordinate system of the position sensor receiver and B-scan is calculated using the least-squares fitting algorithm. At last, the calibration result is evaluated on two criteria: precision and accuracy. The result shows that our phantom is convenient as well as reliable for freehand spatial calibration.
X. Y. Wang et al., "Freehand 3D Ultrasound Calibration Based on Two-Layer Z-Fiducial Phantom", Advanced Materials Research, Vols. 317-319, pp. 638-642, 2011