The principle of vacuum blood collection tube

The principle of the vacuum blood collection tube is to pre-pump the blood collection tube with the head cover to different degrees of vacuum, and use its negative pressure to automatically and quantitatively collect venous blood samples. Human venous blood is drawn into the blood sample container through the blood collection needle under the action of negative pressure in the vacuum blood collection tube. Under one venipuncture, multiple tubes can be collected without leakage. The volume of the lumen connected to the blood collection needle is very small, and the impact on the blood collection volume can be ignored, but the probability of reverse flow is relatively small.