2.4. Pulmonary Function
apnoea
THORACIC
The used devices: FEV1 will be used to assess lung function. A spirometer (as used by Burt et al., [Test method: FEV1 was evaluated by allowing the patients to sit on a chair at the height of (40 cm), where the feet are touching the ground, and the back is straight and resting on the back of the chair. The researcher begins to teach the patient the technique of the test by taking a deep inhale and then forcefully and quickly expelling the air from the chest (exhale) until the lungs empty or until the device makes a sound, and the nose is closed with an airtight stopper to ensure that the inhalation is taken out from the mouth only. Scoring method: the patients must continue to completely expel the exhaled air until apnoea and the inability to continue, and it must be at least (6) seconds and may last up to 12 seconds or more, and the test was performed on three attempts for each patient with one-minute rest among tests recording the best performance, noting that the reading of the attempt appears directly on the device's screen, and then, it is printed to become a graph paper, and the unit of measurement is the percentage (%).Spirometer (German type) measurements were conducted under American Thoracic Society (ATS) guidelines [