A systematic review of pandemic ventilator designs

This paper presents a systematic literature research and review of ventilator systems developed during the COVID-19 pandemic. Peer-reviewed journal and conference articles published through January 16th, 2025 were screened, and eligible systems were classified by actuation principle. Performance criteria were derived from Emergency Use Authorization requirements and used to generate a score-based ranking for each class. Performance was analyzed within and across classes to identify the situations in which each actuation principle is most advantageous. As an indicator of study quality, we evaluated the testing modalities reported for each device. Valve-based ventilators emerged as the most mature class in terms of ventilation functionality and testing. An emerging class of bag-based systems performed remarkably well compared with established valve- and blower-based designs. Across all three classes, the most frequent shortcomings concerned oxygen dosage of the inspired gas and the implementation of monitoring and alarm functions. Finally, we provide recommendations on development processes, testing procedures, and mitigation of supply-chain vulnerabilities that may support ventilator development in future pandemics.