Comparison of two devices for respiratory impedance measurement using a forced oscillation technique: basic study...

Area of Science:

• Respiratory Physiology
• Medical Device Technology

Background:

• Forced oscillation technique (FOT) devices are widely used for physiological assessments, particularly for obstructive lung diseases.
• The comparability of impedance values measured by different FOT devices has not been established.

Purpose of the Study:

• To compare impedance measurements between two commercial FOT devices: the impulse oscillometry system (IOS) and the MostGraph (MG).
• To assess device-specific variations in resistance and reactance under controlled conditions.

Main Methods:

• Phantom models were utilized to compare the IOS and MG devices.
• Resistance and reactance values were measured and analyzed for differences in accuracy and frequency dependence.

Main Results:

• Both IOS and MG devices showed resistance variations up to 10% from estimated values.
• Significant differences in frequency dependence of resistance were observed between the devices.
• MG measured higher reactance values than IOS.
• Ventilation effects on impedance measurements were more pronounced with IOS, especially at lower frequencies.

Conclusions:

• Commercial FOT devices do not consistently produce identical impedance values.
• Differences between IOS and MG devices must be considered when interpreting clinical data.
• Further research is warranted to standardize FOT device measurements for consistent clinical application.