Reliability of Different FOT Devices to Measure the Human Respiratory Impedance

Comparison of the Reliability of Different Devices to Measure Lung Function With the Forced Oscillation Technique

The objective of the study is to evaluate the reliability of the impedance data in adult subjects measured with five different FOT devices.

The purpose of the study is to evaluate the reliability of the respiratory impedance measured with different FOT (=Forced Oscillation Technique) devices. To this end, the respiratory impedance of fifty adult subjects will be measured in random order with five different forced oscillation devices. As there is no "gold standard" FOT-device, each setup will be compared to all other setups.

Secondary study questions are: 1) is there a specific comfort (or discomfort) associated with the different measuring devices 2) Guidelines state that full chin and cheek support should be applied when measuring the human respiratory impedance. What is the influence of a partial cheek support?

Inclusion Criteria:

• Healthy adult subjects
• Adult patients with obstructive lung disease

Exclusion Criteria:

• Inability to perform lung function tests
• Patients with respiratory failure
• Patients on BIPAP-therapy
• Patients on supplemental oxygen.