CFR › Title 21 › Part 870 › §870.430021 CFR §870.4300Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy link(a)Identification. A cardiopulmonary bypass gas control unit is a device used to control and measure the flow of gas into the oxygenator. The device is calibrated for a specific gas.(b)Classification. Class II (performance standards).