Numerical and experimental evaluation of nasopharyngeal aerosol administration methods in children with adenoid hypertrophy.

Administering aerosol drugs through the nasal pathway is a common early treatment for children with adenoid hypertrophy (AH). To enhance therapeutic efficacy, a deeper understanding of nasal drug delivery in the nasopharynx is essential. This study uses an integrated experimental, numerical modelling approach to investigate the delivery process of both the aerosol mask delivery system (MDS) and the bi-directional delivery system (BDS) in the pediatric nasal airway with AH. The combined effect of respiratory flow rates and particle size on delivery efficiency was systematically analyzed. The results showed that the nasopharyngeal peak deposition efficiency (DE) for BDS was approximately 2.25-3.73 times higher than that for MDS under low-flow, resting and high-flow respiratory conditions. Overall nasopharyngeal DEs for MDS were at a low level of below 16 %. For each respiratory flow rate, the BDS tended to achieve higher peak DEs (36.36 % vs 9.74 %, 37.80 % vs 14.01 %, 34.58 % vs 15.35 %) at smaller particle sizes (15 µm vs 17 µm, 10 µm vs 14 µm, 6 µm vs 9 µm). An optimal particle size exists for each respiratory flow rate, maximizing the drug delivery efficiency to the nasopharynx. The BDS is more effective in delivering drug aerosols to the nasal cavity and nasopharynx, which is crucial for early intervention in children with AH.

[Effect of nasal swell body on nasal airflow and Artemisia pollen deposition].

Objective:The nasal swell body（NSB） consists of the nasal septal cartilage, nasal bone, and swollen soft tissue, all of which are visible during endoscopic and imaging examinations. Although the function of the NSB remains uncertain, there is evidence to suggest that it plays a vital role in regulating nasal airflow and filtering inhaled air. Based on anatomical and histological evidence, it is hypothesized that the NSB is indispensable in these processes. This study aims to investigate the impact of NSB on nasal aerodynamics and the deposition of allergen particles under physiological conditions. Methods:The three-dimensional （3D） nasal models were reconstructed from computed tomography （CT） scans of the paranasal sinus and nasal cavity in 30 healthy adult volunteers from Northwest China, providing basis for the construction of models without NSB following virtual NSB-removal surgery. To analyze the distribution of airflow in the nasal cavity, nasal resistance, heating and humidification efficiency, and pollen particle deposition rate at various anatomical sites, we employed the computed fluid dynamics（CFD） method for numerical simulation and quantitative analysis. In addition, we created fully transparent segmented nasal cavity models through 3D printing, which were used to conduct bionic experiments to measure nasal resistance and allergen particle deposition. Results:①The average width and length of the NSB in healthy adults in Northwest China were （12.85±1.74） mm and （28.30±1.92） mm, respectively. ②After NSB removal, there was no significant change in total nasal resistance, and cross-sectional airflow velocity remained essentially unaltered except for a decrease in topical airflow velocity in the NSB plane. ③There was no discernible difference in the nasal heating and humidification function following the removal of the NSB; ④After NSB removal, the deposition fraction（DF） of Artemisia pollen in the nasal septum decreased, and the DFs post-and pre-NSB removal were（22.79±6.61）% vs （30.70±12.27）%, respectively; the DF in the lower airway increased, and the DFs post-and pre-NSB removal were（24.12±6.59）% vs （17.00±5.57）%, respectively. Conclusion:This study is the first to explore the effects of NSB on nasal airflow, heating and humidification, and allergen particle deposition in a healthy population. After NSB removal from the healthy nasal cavities: ①nasal airflow distribution was mildly altered while nasal resistance showed no significantly changed; ②nasal heating and humidification were not significantly changed; ③the nasal septum's ability to filter out Artemisia pollen was diminished, which could lead to increased deposition of Artemisia pollen in the lower airway.

[Application of impulse-radio ultra-wideband radar as a non-contact portable monitoring device for the diagnosis of obstructive sleep apnea].

Objective:To compare the effect of impulse-radio ultrawideband（IR-UWB） radar technology and polysomnography（PSG） in sleep assessment. Method:A total of 79 OSA patients were randomly divided into two groups: 40 patients in group A received PSG and IR-UWB, and 39 patients in group B received micromovement sensitive mattress（MSM） and IR-UWB. Pearson correlation and ROC curve were used for statistics. Result:AHI PSG and AHI MSM were significantly correlated with AHI IR-UWB（r=0.91, P＝0.00; r=0.92, P＝0.00）. Bland-Altman analysis showed that AHI IR-UWB value was highly consistent with AHI PSG value（95.00%）, and AHI IR-UWB value（97.44%）. The sensitivity and specificity of AHI IR-UWB compared with PSG were 70.40% and 89.90%, respectively. The area under ROC curve was 0.915. Conclusion:IR-UWB has a high diagnostic value for adult OSA in terms of minimum blood oxygen saturation, average blood oxygen saturation, average number of central sleep apnea, average number of complex sleep apnea, average heart rate, sleep efficiency, REM sleep duration, average AHI, etc. It is an economic and practical sleep evaluation tool.