Study on the Effect of Incentive Spirometer-based Respiratory Training on the Long COVID-19

The incentive spirometer is a handheld mechanical breathing device that uses a one-way valve to prevent exhalation. It consists of a corrugated tube and a nozzle connected to three consecutive plastic chambers, each containing a ball. The external chambers are marked with the minimum flow required to raise the ball internally. The ball rises when the patient performs slow, deep breathing through the nozzle. If the patient breathes too quickly, the balls in the chambers rise to the top, and if breathing is too slow, the balls fall to the bottom. The number of increasing balls measures the volume of inhaled air. When all three balls reach the top of the chambers, the patient's flow rate can reach 1200 ml/s. After the patient has maximized their inhalation, they are asked to hold the balls in the same position for more than 3 sec.