Mechanical ventilator shortages have become increasingly frequent due to the COVID-19 pandemic. There is an unmet need for low cost, easily assembled emergency-use ventilators that are minimally susceptible to supply chain disruptions. The MADVent is a single-mode continuous, mandatory, pressure-controlled, time-terminated ventilator developed to be easily sourced and assembled for use in emergency scenarios, including COVID-induced acute respiratory distress syndrome (ARDS). This study hypothesizes that the proposed ventilator design can successfully inflate tissue for sustained periods, with waveforms comparable to existing ventilators on the market. The main aim of this study is to determine if the MADVent Mark V can safely and effectively inflate mammalian lungs for sustained periods. Sub-aims include (1) optimizing the ventilator design for safety, efficacy, and reduced cost, (2) validating the ventilator on a mechanical lung simulator, and (3) and validating the ventilator on an ex-vivo model. Tests were completed using a mechanical lung simulator or porcine lungs as models. Pressure, flow, and volume data were collected and processed using BIOPAC’s respiratory data acquisition hardware and software. Parameters including respiratory rate, inspiration time, target pressure, and compliance were varied across trials with both models to simulate various clinical conditions including extreme scenarios and long durations. Dynamic compliance of the porcine lung was calculated to be 0.037 L/cmH2O, which is comparable to the compliance applied during most mechanical model trials. The MADVent Mark V effectively mechanically ventilates both mechanical lung simulators and ex-vivo porcine models. Next steps include preparing an FDA submission.