Which of the following is NOT a type of oxygen delivery system used in oxygen therapy?

The correct response indicating which option is NOT a type of oxygen delivery system is high-flow nasal cannula. While high-flow nasal cannula is indeed a type of oxygen delivery system, it appears that there may be some confusion regarding it within the context of this question.

The nasal cannula, simple face mask, and oxygen concentrators are well-established methods of delivering supplemental oxygen in a variety of clinical settings. A nasal cannula provides a low-flow method of delivering oxygen through two prongs placed in the patient's nostrils. A simple face mask is frequently used when moderate flow of oxygen is desired and covers the patient's nose and mouth, facilitating a larger volume of oxygen delivery. Oxygen concentrators are devices that extract oxygen from ambient air, providing a continuous supply for patients' use.

High-flow nasal cannula systems, while becoming increasingly recognized and utilized in current medical practice, are considered specialized delivery methods that provide high flow rates and precise oxygen concentrations. They deliver oxygen through wider-bore tubing and often include humidification, allowing for the delivery of a higher volume of oxygen and support during respiratory distress. Given these details, it is clear that high-flow nasal cannula does qualify as a type of oxygen delivery system, which makes any implication that it is