Schematic diagram of main pressure of infusion bottle

The schematic diagram of the principle pressure of the hanging bottle is as follows:

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There are two pipes under the infusion bottle, one is the channel for the downward flow of liquid, and the other is the air inlet. When the liquid flows downward, the air pressure in the bottle decreases in turn, and the air is forced by the atmospheric pressure from the air inlet pipe, so that the air pressure above the liquid level in the bottle is always slightly lower than the atmospheric pressure, so the air pressure above the liquid level can be kept constant.

The liquid in the infusion bottle can flow out at a uniform speed (a Murphy's dropper is connected in the middle of the infusion tube below the infusion bottle). This little instrument used to be made of glass, but now it is made of plastic. The regulator is used to adjust the dropping speed of the medicine dripped into Murphy's tube, and the medicine must stay under Murphy's tube, so that the infusion pressure can be kept constant, that is, the infusion speed is constant. )

Using the physical principle of hydrostatic pressure, the liquid is input into the body. The infusion bottle is a glass bottle with an inlet connected to the atmosphere and a rubber tube under it. The liquid in the bottle is influenced by atmospheric pressure, which makes the liquid flow into the rubber tube to form a water column. When the water column pressure is greater than the venous pressure, the liquid in the bottle flows into the vein smoothly.

During infusion, the doctor first hangs the glucose bottle upside down, and then inserts a ventilation needle on the ventilation tube. At this time, the vent pipe is communicated with the glucose bottle, and part of the glucose solution enters the vent pipe.

However, we noticed that the amount of water entering was not much, and the liquid level in the snorkel was much lower than that in the glucose bottle. Then the doctor connects the drip glass tube with the infusion tube, and then connects the infusion tube with the glucose bottle through the needle. Adjust the clamp on the hose, and the glucose water begins to drip evenly in the glass drop tube.

During the whole infusion process, the downward pressure on the small liquid sheet at the top opening of the snorkeling needle is basically maintained at an atmospheric pressure level, which will not change because of the drop of the liquid level in the bottle. Because the liquid pressure on the horizontal plane where the top end of the snorkel needle is located in the figure remains basically unchanged, the liquid pressure at the drop glass tube port at a certain distance below it also remains basically unchanged. This has played a positive role in stabilizing the rate of decline.