Answer:
Dry suction chest tube system
Explanation:
The dry suction drains that are self-regulating today use a small, adjustable regulator installed into the drain.
So long as there is enough air flow from the suction of the wall (that will be shown on the drain) it will respond correctly to changes in the pressure of the source or the patient to retain suction at the drain level.
It's also a quiet mode of activity.