Groundbreaking Self-Breathing Ventilator Investigation

Researcher: Hayley Yukihiro | Faculty Advisor: Wayne Strasser

With the rise in global devastation created by the COVID-19 pandemic, the world needs a cheap, simple, and disposable ventilator containing no moving parts. We computationally explore the intricacies of the world’s smallest ventilator, the HOPE inVent. When connected to a modest motive gas source, this 3-D printed device will self-pulse and ventilate an unconscious patient or support the breathing of a conscious patient. Pulsations occur because of the well-known Coanda effect coupled with acoustic interactions and turbulent instabilities at various scales. Despite the promising results of the preliminary design of the self-pulsating ventilator, fundamental challenges remain with lack of repeatability and predictability in manufacturing. The breathing characteristics are highly sensitive to micron-level internal geometric parameters and their interactions in ways that are not currently understood. In order to understand the underlying principles, we utilized proven computational fluid dynamic modeling techniques to verify its efficacy through experimental analysis. A steady-state analysis was carried out to study the ratio of entrainment, air pulled into the ventilator’s exhaust port during inhalation, to geometric parameters. The results demonstrated no correlation in the parameters studied thus proposing more work is needed to determine the best mechanism for predicting the resulting entrainment ratio from geometry parameters.