Effect of particle size distribution on the transmission efficiency of atomized water to the tracheal tube

Ultrasonic atomization is a widely used technology. As the atomization device, lead zirconate titanate (PZT) and lithium niobate (LN) are comparatively investigated through experimental and numerical schemes. However, knowledge on a profitable scheme by which to efficiently deliver the atomized particles into the tracheal tube remains unclear. In this study, the physical difference of the transmission efficiency of water particles atomized by PZT and LN devices was measured. The water particles atomized by PZT and LN were injected into a human airway model including a nasal cavity and bronchial tube. The distribution of the amount of transmitted particles deposited at each of the monitoring positions was then estimated using the results of image analysis of color intensity. As a result, the atomized particles of the PZT device, which produced larger particles than the LN device, were more strongly affected by inertia and tended to be deposited at the area closer to the entrance of the nasal cavity. In contrast, the particles produced by the LN device tended to be transmitted deeper into the trachea. The experimental results indicated that the particle size distribution of PZT and LN, which have quite different maximum sizes of particles, largely influences the spatial distribution characteristics of particle deposition along the airway from the nasal cavity to the trachea.