Optimized open-source setting for subjecting rodents to chronic normobaric hypoxia in facilities with minimal nitrogen supply.

Hypoxia research employs animal models based on chronically breathing hypoxic air (O2<21%), usually by injecting N2 into the animal’s chamber. However, continuous high-flow N2 supply is available only in limited facilities, reducing the capability of widely conducting hypoxia research.

Here, we describe an optimized setting for subjecting rodents to chronic normobaric hypoxia by requiring minimal N2 supply. The setting is based on providing the O2 consumed by the animals and eliminating the exhaled CO2 and water vapor. O2, CO2, temperature, and humidity in the hypoxic chamber are controlled by an Arduino-based unit activating a pump that introduces room air to restore the metabolized O2.