Which gas delivery method does NOT require external tanks or tools to operate effectively?

Integrated oxygen cylinders are designed to function without the need for external tanks or additional tools for operation. These systems typically have built-in regulators that allow for direct delivery of oxygen from the cylinder, making them user-friendly and convenient for both medical personnel and patients. Since they are self-contained, users can simply turn on the oxygen and adjust the flow as needed, streamlining the process of delivering medical gas without complicated setups.

In contrast, other options such as Thorpe tubes and Bourdon gauges are devices used to measure gas flow and require a separate gas source to operate. Additionally, portable oxygen systems, while designed for mobility, still rely on external tanks to store gas, which means they cannot function independently of external equipment. This highlights the unique feature of integrated oxygen cylinders, which combine storage and delivery into one seamless unit.