Respiratory function will be assessed by a qualified and certified evaluator in each hospital. This is typically a respiratory therapist or physiotherapist. The participating boys will be instructed on the use of the hospital-based spirometer and a handheld nmd-1 device.

Boys will be asked to use the nmd-1 device, an easy to use device that monitors respiratory function at home, once a week. The home device is used to have more data points, and a more sensitive measure, of respiratory function decline.

At each study visit, the evaluator will download the data from the home device.  The boy also will be asked to repeat the respiratory function test with the home device during each study visit.

Respiratory function measurements will include:

  • 1

    Forced Vital Capacity

    The total amount of air that you blow out in one breath with full force after a maximum inspiration
  • 2

    Peak Expiratory Flow

    The peak expiratory flow rate test measures how fast a person can exhale
  • 3

    Forced Expiratory Volume in 1 second

    The amount of air you can blow out within one second
  • 4

    Peak Cough Flow

    The speed of air being blown out from the lungs after a cough maneuver
  • 5

    Blood oxygen saturation level measured with a pulse oximeter

    Oxygen is carried in the blood attached to haemoglobin molecules. Oxygen saturation is a measure of how much oxygen the blood is carrying as a percentage of the maximum it could carry
  • 6

    End tidal CO2 level measured by capnography

    Maximal concentration of carbon dioxide (CO2) at the end of an exhaled breath

For all respiratory assessments the highest value from a minimum of three, and up to five, consecutive maneuvers will be used.