Chest drainage unit

Claim 1

In a chest drainage apparatus comprising a casing having a collection chamber therein for receiving fluid to be drained from a chest cavity, means defining an inlet opening into said collection chamber for establishing fluid communication between said collection chamber and a patient's chest cavity to be drained, means defining an outlet adapted to be connected in fluid communication with a source of suction, means defining a liquid seal between said collection chamber and said outlet, and a suction regulator for limiting the amount of suction applied to said collection chamber via said outlet and said liquid seal, the improvement comprising: said suction regulator comprising: a regulator housing defining a suction regulator chamber; means defining an outlet opening from said regulator chamber which is in fluid communication with said collection chamber via said liquid seal; means defining an inlet opening into said regulator chamber which is adapted to be connected to a source of suction; pressure responsive means responsive to suction above a predetermined level in said collection chamber to block suction above about said predetermined level from said inlet opening chamber until the suction in said collection chamber drops to about said predetermined level; said pressure responsive means comprising a flexible diaphragm in said regulator chamber; a nozzle extending into said inlet opening in said regulator chamber; said nozzle including an outlet opening disposed adjacent one surface of said flexible diaphragm, whereby suction above said predetermined level at said one surface of said diaphragm in the vicinity of said nozzle will move a portion of said diaphragm against said nozzle outlet; and means for manually moving said nozzle toward and away from said flexible diaphragm so as to vary said predetermined level of suction at which said diaphragm in the vicinity of said nozzle will move against said nozzle outlet.