1, simple and lightweight: exhaust takes up a certain amount of space and weight, which will increase the volume and weight of the transfusion device, making it less convenient to use. Therefore, other exhaust methods are used, such as the use of negative pressure design, by pumping out the air inside the transfusion device, so that the pressure inside the transfusion device is reduced, thus avoiding the risk of air embolism and so on.
2. Condition limitation: In some medical environments, such as field emergency or battlefield medical care, there is not enough space and conditions to install exhaust.