Ventilator ventilation parameter vr refers to tidal volume. Tidal volume usually refers to the volume of air inhaled or exhaled each time in the resting state, which is related to age, gender, volume surface, breathing habits, and muscle metabolism. The set tidal volume usually refers to the volume of inhaled air. The set tidal volume is not constant and should be adjusted according to the patient's blood gas analysis. Normal is 8-10 ml/kg for adults and 10-15 ml/kg for pediatrics.A ventilator is a medical device that delivers oxygenated air into the lungs and expels carbon dioxide-containing gases out of the body to help the respiratory system complete ventilation.