2.4. Short-/Long-Axis Switching Double-Screen Control Method
The ultrasound probe was placed parallel to the clavicle by the middle point of the clavicle (the ultrasonic mark point was located at the upper right), and an appropriate section was identified to enable the subclavian artery and vein to be displayed in the center of the screen simultaneously. On the short-axis plane, according to the position relationship, fluctuations, and changes in pressure, the artery and vein could be quickly determined. The double-screen mode was selected, and the standard short-axis anatomical plane was selected on the left screen. Generally, the artery is located on the lower side, while the vein is located on the upper side. The slightly overlapped update key was selected to switch to the right screen, and the probe position was maintained as it was rotated counterclockwise (In the plane, the angle of entry was 45°. When the puncture needle entered the vein, dark black blood was drawn back under negative pressure and the guide wire was inserted (The structure of the subclavian vein was displayed on the left screen. At the same time, the right screen used in-plane puncture technology, which only displayed the target blood vessel, clavicle, and pleura in the plane. The target blood vessel could be punctured directly in real time for the far position of the pleura, and the clavicle needle could be inserted at a shallow angle for the near position of the pleura. Then, the needle was withdrawn by 0.5–1.0 cm, and the tail of the needle was raised close to the clavicle to complete the puncture.