A time-multiplexing approach to shared ventilation

Ventilator shortages during the COVID-19 pandemic forced some hospitals to practice and many to consider shared ventilation, where a single ventilator is used to ventilate multiple patients simultaneously. However, the high risk of harm to co-ventilated patients secondary to the inability to treat anatomically different patients or safely adapt to dynamic ventilation requirements has prevented full adoption of multi-patient coventilation. Here, a time-multiplexing approach to shared ventilation is introduced to overcome these safety concerns. A proof-of-concept device consisting of electromechanically coupled ball valves to induce customized resistances and facilitate the delivery of alternating breaths from the ventilator to each patient is presented. The approach successfully ventilated two test lungs, and individualized tidal volume combinations of various magnitudes were produced. Over five hours of co-ventilation, consistency in tidal volume delivery was comparable to independent ventilation. Time-multiplexing was able to facilitate delivery of statistically unique tidal volumes to two test lungs and maintain the consistency of tidal volumes within each test lung while independently ventilated with identical parameters. The ability to adjust each test lung's inspiratory pressures dynamically and independently was also demonstrated. The time-multiplexing approach has the potential to increase the viability of co-ventilation for ongoing and future ventilator shortages.