Evaluation of the 'SmartVent' portable ventilator: Performance in a lung model and in dogs

Objective: Evaluation of the performance of 'SmartVent', a new computer-controlled portable ventilator. Design and methods: This study was performed by using a mechanical lung model with tidal volumes varying from 20 to 500 ml, resistance levels of 5-50 cm H₂O/l/sec and compliance ranging from 0.01 to 0.1 l/cm H₂O at 10-60 breaths per minute. The device was further checked for its ability to ventilate five anaesthetized dogs under conditions similar to the in vitro study. Arterial blood gas (ABG) analyses and respiratory patterns during the experiment were recorded. Results: In all in vitro circumstances, when one of the parameters (resistance, compliance, frequency) were modified, the V(t) (tidal volume) obtained was close to the pre-set volume. The ventilator successfully controlled blood oxygen levels and alveolar ventilation in all dogs in each of the combination of parameters. Conclusion: The results demonstrated that the 'SmartVent' was able to accomplish the pre-established goals in dogs, namely the preservation of V(t) in an in vitro set-up, and close to normal values of alveolar ventilation and ABG levels.