Abstract Rationale The VortexPAP is a novel medical device that delivers continuous positive airway pressure (CPAP) therapy using pulsating, vortical airflow. Prior investigations have demonstrated that VortexPAP can achieve therapeutic pharyngeal pressure levels without requiring a tight-fitting mask and is a comfortable, effective alternative for obstructive sleep apnea (OSA) management. This study aims to evaluate the effect of continuous flow versus pulsatile vortical airflow in pressurizing a 3D-printed, patient-specific upper airway model with simulated breathing. Methods Computed-tomography (CT) scans of an adult upper airway were segmented using 3D Slicer and exported into nTop for surface offset and shell model generation. The final geometry was fabricated via stereolithography (SLA) and connected to a Michigan Instruments dual adult lung simulator to emulate healthy adult breathing. Airflow from the VortexPAP was delivered to the nares of the model in two modes: (1) continuous flow and (2) pulsatile vortical flow (∼20 Hz). Each flow mode was tested at mean flow rates of 60, 70, 80, and 90 L·min-1. Pharyngeal and lung pressures were measured using OMEGA PX459 pressure transducers sampled at 1 kHz. The flow conditions were evaluated for ∼7 breathing cycles (∼30 sec). Flow output was independently verified using hot-wire anemometry. Results For a given mean flow rate, the VortexPAP’s pulsatile vortical airflow outperformed continuous airflow in pressurizing the pharynx of the adult upper airway geometry during simulated breathing (Fig. 1). On average, a 167% increase in mean normalized pharyngeal pressure was observed when comparing pulsatile vortical airflow to continuous airflow across the tested flow rates, over multiple breathing cycles. Conclusion The VortexPAP showcased superior pressurization of the upper airway when compared to continuous airflow in a 3D-printed, patient-specific upper airway model with simulated breathing. These results serve to further corroborate this device as a comprehensive alternative to traditional CPAP therapy for the management of OSA. Fig. 1. Plot comparing the measured, normalized pharyngeal (gauge) pressure in the 3D-printed, patient-specific upper airway model at mean flow rates of 60, 70, 80, and 90 L-min-1 for continuous and pulsatile vortical airflow modes This abstract is funded by: None
Kalaiarasan et al. (Fri,) studied this question.