Development of an Upper Airway Model in a 32 Weeks Gestational Age Premature Newborn

Background: Effective airway passage of aerosols in respiratory therapy of neonates is crucial for a positive outcome. Therefore, devices aimed at delivering aerosols to the lungs such as inhalers and nebulisers must be studied thoroughly. For this purpose we constructed an anatomically correct model of the upper airways in a 32 weeks gestational age premature infant. Objective: This study describes the construction process, validation and characterization of this airway model. Methods: Three-dimensional reconstruction of a three-planar MRI scan was done using Magics© software (Materialise™, Munich, Germany) followed by selection of an optimal air-mucosa threshold. Model reconstruction was achieved using the generated data and Selective Laser Sintering Technique. Subsequently, validation was realized between the original data and a CT scan of our model by comparison of airway volume and anatomical reference points. Results: The construction process proved to have a high accuracy. The airway volumes of the initial MRI and the control CT scan showed to be 1277 mm3 and 1265mm3, respectively. The final relative deviation in volume was 0.94 percent. Conclusion: We constructed an anatomically correct model of the upper airways of a 32 week-old premature infant with high accuracy. This model is suitable for further in vitro measurements such as lung dose measurements of aerosols.