2024 年 38 巻 2 号 p. 32-38
Assessing the mechanical properties of the airway, such as compliance and viscoelasticity, is essential for diagnosing respiratory conditions particularly given the significant demand for evaluating the respiratory system since the onset of COVID-19. Traditional methods such as spirometry and plethysmography have limitations including patient discomfort and the need for active effort. We present a novel, noninvasive method using air pressure applied via a mouthpiece connected to a linear actuator. Experiments with subjects exhibiting normal respiratory function demonstrated the feasibility and accuracy of this method, minimizing patient discomfort. Pressure changes in response to rapid volume reduction within the mouthpiece induced by the actuator were analyzed using a viscoelastic Maxwell model. This approach allowed for the extraction of both compliance and viscoelastic properties with high reproducibility. The results showed that airway compliance, a measure of elasticity, varied with different breathing states, while fluidity, reflecting viscoelastic properties, remained consistent. While further research and clinical validation are needed, these findings indicate that this method has the potential to become a promising tool for respiratory diagnostics.
