Estimation of wire phantom's position in ultrasound probe calibration based on polynomial equation

The primary problem in the reconstruction of the 3D ultrasound image is the calibration of the probe. This paper presents a method of estimating wire phantom's position within the calibration system of the ultrasound's probe. Calibration process was done by probe scanning above the phantom, in this case using copper wires. Depends on the position and orientation probe to wires phantom, scanning process produced some types of images of phantom. The phantom will generate random distribution intensity in the B-mode ultrasound images. The intensity of the image often exceed a maximum value and produce image saturation. The saturated image, usually includes many saturated pixels. To find the accurate position of a phantom in the B-mode images, it requires modeling the distribution of saturated pixels. Data distribution in the ultrasound image was approximated using 5^th degree polynomial equation to compute the coordinate of image maximum value. This experiments show that one centimeter is equivalent to 122.72 pixels, and the average error is (17×10^-5) %. By calculating of the center of mass of wire image, obtained that one centimeter is 123.01 pixels, and an average error is (20.9×10^-5)%.