Principle of vacuum blood collection

        The principle of vacuum blood collection tube is to pre-extract the blood collection tube with the head cover into different vacuum degrees, and automatically collect the venous blood sample by using the negative pressure. The blood collection needle is inserted into the human vein and the other end is inserted into the rubber plug of the vacuum blood collection tube. The venous blood of the human body is inside the vacuum blood collection tube, and under the action of negative pressure, the blood sample container is drawn through the blood collection needle, and under one venous puncture, multi-tube collection can be realized without leakage. The volume of the lumen connected to the blood collection needle is small, and the influence on the blood collection volume is negligible, but the probability of occurrence of countercurrent is relatively small. If the volume of the lumen is large, the vacuum degree of a part of the blood collection tube is consumed, thereby reducing the collection amount.