Measuring and determination of tidal volume of the ventilator tester by different methods

Abstract

Accurate tidal volume measurement is essential for the calibration and verification of ventilator testers to ensure the reliable performance of mechanical ventilators. This study compared and evaluated three calibration methods: A Molbloc reference flow meter, wet gas reference flow meter, and calibration volumetric syringe. The Molbloc flow meter demonstrated consistent results with a measurement uncertainty of ±0.29%. While the wet gas meter exhibited minimal error at lower volumes but showed increased inaccuracies at a volume of 400 mL due to rotor movement issues. Conversely, the volumetric syringe method provided the highest accuracy, with a measurement uncertainty of ±0.27%. The high accuracy is mostly due to its direct volumetric displacement and precise calibration standards. The syringe method also simulated real human breathing dynamics across a wide range of flow rates (0.1–34 L/min), enhancing its applicability in realistic ventilator testing. Comparative analysis revealed that the syringe method is the most reliable and precise, making it the preferred choice for tidal volume calibration in clinical and laboratory settings.