This is: the push-type safety distal blood collection needle is disposable and its structure cannot be restored after use, so secondary blood collection cannot be performed.
His assembly sequence is: structure 2 snaps into structure 1, the spring is pre-compressed after snapping in, and a certain amount of spring is stored waiting to be released. Then put the assembled structure 1 and structure 2 into structure 3, and finally assemble them together into structure 4.
His working principle is: the tail end of structure 3 has a small trapezoidal front end. When structure 1 is pressed, it will enter the trapezoidal position of structure 3. At this time, the card position of structure 1 and structure 2 will become larger and larger. When reaching a certain amount, the preloaded spring-loaded structure 2 will pop up. The moment when the spring pops out of the structure 2 can complete the puncture of the finger in as little as 0.3 seconds, thereby achieving the purpose of blood collection.
1. Blood collection needle
Answer: A blood collection needle used to collect blood samples during medical examination. It consists of a needle and a needle bar. The needle is located at the head of the needle bar. , a sheath is slidably connected to the needle bar, a return spring is provided between the sheath and the needle bar, and the initial position of the sheath is located at the head of the needle and the needle bar. When the operator holds the needle and presses the head of the blood collection needle against the patient's limb, the sheath retracts under the elasticity of the skin, causing the needle to protrude and penetrate the skin, causing minimal trauma. When the blood collection needle is removed, the sheath is in contact with the return spring. Reset it under the action to cover the needle to prevent the needle from being exposed and contaminated or accidentally stabbing the human body. When the blood collection needle is removed, the cavity between the needle tube and the skin gradually increases, forming an instant negative pressure, which is beneficial to the collection of blood samples.