The medical flow meter is a medical device for oxygen or medical air inhalation of first-aid and hypoxic patients in the hospital, including oxygen flow meter and medical air flow meter/rotameter.

The working principle of the oxygen in the bottle is to reduced by the pressure reducer. The pressure action changes from the original high-pressure oxygen to low-pressure oxygen and after the flow is regulated by the oxygen flow meters/rotameter.

A rotameter is a flow meter that measures volumetric flow of liquids and gases. There is no difference between a rotameter and flow meter.

Hypoxic guard systems are one of the safety systems in anesthesia machines that are designed to avoid the risk of delivering a hypoxic gas mixture to the patient during general anesthesia.

Oxygen flowmeter is an equipment used to control oxygen flow delivery in patients undergoing oxygen therapy.