The principle of vacuum blood collection.

Blood sampling and testing are the most normal testing methods. Although simple, it also contains profound knowledge, with each needle and tube containing knowledge and technology. Today, let me give you a brief introduction to vacuum blood collection.

Vacuum blood collection systems can be divided into two categories. There are two types of blood collection methods: hard connection and soft connection. The difference lies in the blood collection needle. The former is a hard connected blood collection needle, which requires a needle holder for matching; The latter is a soft connection type, which only requires a soft connection type blood collection needle. Due to the convenience of nursing operations and relatively low prices, soft connectors are commonly used in China. Next, let's introduce the core component of a vacuum blood collection system: a vacuum blood collection vessel.

The principle of vacuum blood collection is pressure difference, where blood flows from higher pressure vessels to lower pressure vacuum blood collection vessels, similar to the concept of "water flowing downwards". When it comes to vacuum blood collection, it is not a complete vacuum, but a partial vacuum. During the production process, the manufacturer will extract a portion of the air to create a certain negative pressure inside. For example, this type of blood collection vessel requires a blood volume of 3 ml, and during production, 3 units of air will be extracted to ensure that the blood volume is within the required range; If you require 5 ml of health, then evacuate 5 units of air and so on. There are important knowledge points to tell everyone that blood collection is produced according to demand for two reasons:

1、 Set negative pressure according to the local altitude. Because altitude can affect the local air pressure, the higher the altitude, the lower the air pressure. Similarly, 5 ml of blood needs to be collected. The negative pressure on the plain is a certain number, but at an altitude of 2 kilometers, the negative pressure is another number. It needs to be higher, otherwise the blood volume will not be enough to reach 5 ml.