The approximate distance to which the needle needs to be stuck in during the infusion needs to be considered according to the patient’s specific situation. If the patient belongs to the obese body, considering its fat content is thicker, the blood vessels may be between 1.5-2 centimeters away from the skin, for fat people should be checked in 1.5-2 centimeters away. Normal people due to its fat thickness moderate, subcutaneous blood vessels from the skin, that is, about 0.2-0.6 centimeters, for normal patients infusion when the depth of lancing between 0.2-0.6 centimeters, after which you need to be pushed inside, the needle will not appear to jump. Need to use tape on the outside to fix the treatment after being stuck in, and the depth of the needle is different for different groups of people.