Performance of Vitalograph wedge-bellows spirometer--comparison with a rolling seal spirometer

Area of Science:

• Pulmonary Function Testing
• Respiratory Mechanics
• Medical Device Evaluation

Background:

• Spirometry is crucial for diagnosing respiratory diseases.
• Accurate spirometer performance is essential for reliable clinical data.
• Comparing different spirometer models aids in selecting appropriate devices.

Purpose of the Study:

• To evaluate Vitalograph spirometer performance against a rolling seal spirometer (Ohio).
• To assess the normality of spirometric measurements.
• To investigate potential fatigue effects from repeated forced expiratory maneuvers.
• To determine the optimal number of tests for reliable results.

Main Methods:

• Ten healthy subjects performed twenty forced expiratory maneuvers on both Vitalograph and Ohio spirometers at one-minute intervals.
• Eleven algorithms were used to analyze the first five maneuvers per subject.
• Spirometric indices, including volume, timing duration, inertia, and resistance, were measured.
• Statistical analysis assessed normality, fatigue, and differences between algorithms.

Main Results:

• The Vitalograph exhibited smaller volume, shorter duration, and higher inertia/resistance compared to European standards.
• The Ohio spirometer met European standards for volume and duration, with lower inertia/resistance.
• Spirometric indices were normally distributed for both devices.
• No significant fatigue effects were observed with repeated attempts.
• No significant differences were found between the eleven analyzed algorithms.

Conclusions:

• Vitalograph spirometer use in repeated forced expiratory maneuvers does not induce fatigue.
• Spirometric indices demonstrate normal distribution in healthy subjects.
• Vitalograph's accuracy for estimating forced expiratory flows (25-50% vital capacity) may be questionable.
• Reporting the best technically satisfactory attempt from multiple measurements is recommended.