Devices and methods for administering carbon dioxide-enriched air in experimental and clinical settings

Although researchers successfully have used carbon dioxide-enriched air in experimental and clinical preparations, its functional properties may differ across laboratories due to procedural differences. Additionally, current procedures may be too simplistic for more complex experimental designs. To address these issues, we present three devices for administering carbon dioxide-enriched air. Although these devices differ concerning variables such as mode of operation, ease and cost of implementation, and complexity of experimental designs that may be undertaken, a reasonable level of standardization may be achieved because the inhalations experienced by participants are functionally equivalent across devices. We discuss advantages and disadvantages of these devices regarding experimental panic provocation and aversive conditioning preparations.