Figure 70-5 Multiplace hyperbaric chamber large enough for one or more patients and tenders. The chamber atmosphere is compressed air. The patient receives 100% O₂ by mask, head tent, or endotracheal tube. Monitors are usually kept outside the chamber because of electrical safety considerations. Monitoring is possible through a porthole. A personnel lock and a transfer lock allow physicians, nurses, or other personnel, in addition to medications, food, and blood samples, to be moved into and out of the chamber without repeated compression and decompression of the patient.