Final answer:
A sequential compression device uses air to create pressure on the veins and treats both legs simultaneously. These devices help improve blood flow and reduce swelling in the legs.
Step-by-step explanation:
A sequential compression device uses air to create pressure on the veins and treats both legs simultaneously. These devices are often used to prevent blood clots and edema in patients who are immobile or have limited mobility, such as after surgery or during long periods of bed rest. The compression provided by these devices helps improve blood flow in the legs, reduce swelling, and decrease the risk of complications.