The objective of this study was to explore different internal flow passages in the patient interface region of a new air-jet–based dry powder inhaler (DPI) in order to minimize device and extrathoracic aerosol depositional losses using computational fluid dynamics (CFD) simulations. The best-performing flow passages were used for oral and nose-to-lung (N2L) aerosol delivery in pediatric extrathoracic airway geometries consistent with a 5-year-old child. Aerosol delivery conditions were based on a previously developed and tested air-jet DPI device and included a base flow rate of 13.3 LPM (delivered from a small ventilation bag) and an inhaled air volume of 750 mL. Initial CFD models of the system clearly established that deposition on either the back of the throat or nasal cannula bifurcation was strongly correlated with the maximum velocity exiting the flow passage. Of all designs tested, the combination of a 3D rod array and rapid expansion of the flow passage side walls was found to dramatically reduce interface and device deposition and improve lung delivery of the aerosol. For oral aerosol administration, the optimal flow passage compared with a base case reduced device, mouthpiece, and mouth-throat deposition efficiencies by factors of 8-, 3-, and 2-fold, respectively. For N2L aerosol administration, the optimal flow pathway compared with a base case reduced device, nasal cannula, and nose-throat deposition by 16-, 6-, and 1.3-fold, respectively. In conclusion, a new patient interface design including a 3D rod array and rapid expansion dramatically improved transmission efficiency of a dry powder aerosol.

本研究的目的是探索新型基于空气喷射的干粉吸入器 (DPI) 的患者界面区域中的不同内部流动通道，以使用计算流体动力学 (CFD) 模拟最大限度地减少设备和胸外气溶胶沉积损失。在符合 5 岁儿童的儿科胸外气道几何形状中，性能最佳的流道用于口腔和鼻对肺 (N2L) 气雾剂输送。气溶胶输送条件基于先前开发和测试的喷气 DPI 设备，包括 13.3 LPM（从小型通风袋输送）的基本流速和 750 毫升的吸入空气量。该系统的初始 CFD 模型清楚地表明，喉咙后部或鼻插管分叉处的沉积与离开流道的最大速度密切相关。在所有测试的设计中，发现 3D 杆阵列与流动通道侧壁的快速膨胀相结合，可以显着减少界面和装置的沉积，并改善气溶胶的肺部输送。对于口服气雾剂给药，与基本情况相比，最佳流动通道将装置、咬嘴和口腔-喉咙沉积效率分别降低了 8 倍、3 倍和 2 倍。对于 N2L 气雾剂给药，与基础案例相比，最佳流动路径分别减少了 16、6 和 1.3 倍的装置、鼻插管和鼻喉沉积。综上所述，