Assessment of Lung Ventilators’ Pressure Alarms System in a Controlled Scenario

Lung ventilator’s alarm system ought to ensure patient care by warning clinicians about the patient's condition. This study aims to present and discuss a technical evaluation of the lung ventilators alarms (higher-pressure, PEEP and obstruction) prescribed in ISO IEC 80601-2-12 performed during the Covid 19 pandemic in equipment that was distributed to meet the demand of critical patients. In subitem 201.12.4.105, the lung ventilator’s alarm system had to detect when the higher-pressure alarm was reached by the airway-pressure measurement at the ventilator breathing system, and then triggered a high priority alarm. PEEP alarm condition is described in subitem 201.12.4.106 and the obstruction alarm in subitem 201.12.4.107. Ten different lung ventilators were analyzed based on table 201.101 from ISO 80601-2-12. Only one of ten lung ventilators correctly alarmed obstruction and reduced the pressure level to PEEP. Three of them did not present a PEEP alarm and one lung ventilator equipment allowed to disable the high airway pressure alarm. This study demonstrates the current limitations of the lung ventilators’ alarms in a controlled scenario. The studied lung ventilators presented incongruity with the ISO 80601-2-12, especially the obstruction alarm.