Lateral resolution target group, target wire diameter is 0.1mm. They are located at depths of 10, 20, 30, 40, 50, 60, and 70mm respectively. The center spacing of the target wires in each group is 0.35, 0.5, 1, 2, and 3mm from left to right. The distribution of the target wires of the lateral resolution target group is shown in Figure 2 Target Group M and the distribution of the target groups in Table 1.

Axial resolution target group, target wire diameter is 0.1mm. The top target line in each target group is located at a depth of 10, 20, 30, 40, 50, 60, and 70 mm, respectively. The vertical distances between each target line in each group and the corresponding lateral resolution target line above it are 3, 2, 1, 0.5, and 0.35 mm from left to right, respectively, and the horizontal distances between the target lines are 0.2 mm (i.e., horizontal staggered spacing). The target line distribution diagram of the axial resolution target group is shown in target group M and target group N in Figure 2 and the target group distribution in Table 1.

 

Blind target group, target line diameter is 0.1 mm. The horizontal spacing between the centers of the four adjacent target lines on the right is 10 mm, and the distances to the sound window are 5, 6, 7, 8, and 9 mm, respectively. The horizontal spacing between the centers of the three adjacent target lines on the left is 15 mm, and the distances to the sound window are 1, 2, 3, and 4 mm, respectively.

Longitudinal target group, target line diameter is 0.1 mm. There are 12 target lines in total, and the center distance between two adjacent lines is 10 mm.

Horizontal target group, target line diameter is 0.1mm. E1 is located at a depth of 20mm, E2 is located at a depth of 40mm, and the center distance between the two adjacent lines is 10mm.

 

The TM material is embedded with three cystic simulated lesions, all of which are cylindrical with diameters of 2, 4, and 6mm respectively. The axis of the column is parallel to the target line, and the axis is located at a depth of 10, 30, and 50mm respectively.