2.2. Functional Validation of the CPAP-AirFlife™ Flow Generator
MSA, HIT
This section provides a comprehensive overview of the tests conducted to validate the flow generator, a crucial component responsible for controlling flow and oxygen concentrations in the device. The testing process involved meticulously examining the flow generator valve performance, oxygen concentration, flow rates, and PEEP pressure parameters within a closed circuit with limited ventilation and a PEEP valve. A well-designed test rig was assembled to ensure accurate and reliable results, as depicted in During the testing procedure, various measurement instruments were utilized. The SIARGO MF5712 flowmeter (Siargo, Santa Clara, CA, USA) served as the primary tool for measuring flow rates and was cross-referenced with a trusted calibration standard, the TSI 4000 series Mass Flowmeter (TSI Incorporated, Shoreview, MN, USA). To assess oxygen concentration accurately, the digital oxygen measuring instrument CY-12C (CJCMALL, Wuxi, China) was employed and compared with the calibration standard MiniOX I—Model 473030 (MSA, Pittsburgh, PA, USA). The HIT-1890 differential pressure sensor (HIT, Nangang, Harbin, Heilongjiang, China) was used to measure and compare pressure values with the calibration standard TSI 4000 series Mass Flowmeter (TSI Incorporated, Shoreview, MN, USA).To ensure the integrity and effectiveness of the test setup, two HEPA-type antimicrobial filters, a vent hose, and a 10 cmHBefore initiating the characterization process, it is crucial to ensure that the flow generator valves, namely, valves A and B, are fully closed, as depicted in 