Comparison of nasal breathing LB simulation results with rhinomanometry and acoustic rhinometry measurements

Abstract

The accuracy of simulation results to predict surgical outcome to improve nasal breathing is important to satisfy patients. Therefore, in the presented work LB simulation results are compared to acoustic rhinometry and rhinomanometry data. The basis is an already laser Doppler anemometry validated lattice Boltzmann code to simulate nasal breathing. To further investigate the quality of the simulation results, rhinomanometry and acoustic rhinometry data of a patient with nasal septum deviation are used for comparison. The lattice Boltzmann simulation is based on an air-segmented CT dataset. Rhinomanometry and acoustic rhinometry are measurements to evaluate functionality of the nasal breathing process. Both methods are applied on the patient without and with a medication that the swelling of the mucosa is reduced. Lattice Boltzmann simulations show that the results are closer to rhinomanometry without the medication that reduce the swelling of the mucosa. On the left side of the nasal cavity, the simulation is in comparison with rhinomanometry data, in between both measurements. In contrast to the right nasal cavity simulation predict a higher pressure drop (10 %) than rhinomanometry. Segmentation compared to acoustic rhinometry shows up to a distance of 6 cm from the nostril good accordance. However, surgeons experience is that acoustic rhinometry is at bigger distances not trustful anymore. Based on the presented result there is the conclusion that the segmentation process of the CT dataset is a good way to get a digital twin of the nasal cavity that can be used for numerical simulations. As expected simulation and measurements are not coincident. Based on the presented results there is no need to change the segmentation process or imaging technique.