Chest drainage unit having increased airflow capacity with capability to dampon noise

Claim 1

In a chest drainage apparatus having a collection chamber therein for receiving fluid to be drained from a chest cavity, and a suction regulator for limiting the amount of suction applied to said collection chamber, said suction regulator comprising a pressure responsive diaphragm responsive to suction above a pre-determined level in said collection chamber to prevent suction above said pre-determined level being applied to said collection chamber until the suction in said collection chamber drops to about said pre-determined level, and a nozzle including an outlet opening exposed adjacent one surface of said flexible diaphragm, whereby suction above said pre-determined level at said one surface of said diaphargm in the vicinity of said nozzle with move a portion of said diaphragm against said nozzle outlet, and a means for manually moving said nozzle toward and away from said flexible diaphragm so as to vary said pre-determined level of suction at which said diaphragm in the vicinity of said nozzle will move against said nozzle outlet; the improvement comprising: means defining a small outlet opening from said regulator which is in fluid communication with the atmosphere, and which is small enough to effectively dampen the noise created by the vibrations of said diaphragm; means defining a large outlet opening from said regulator which allows for fluid communication bewteen said regulator and the atmosphere, and which is sufficiently large so that in the event of failure of said diaphragm to regulate the amount of suction applied to said patient's chest cavity, the flow of atmospheric air therethrough to enter said regulator will relieve the negative pressure on said patient's chest cavity and maintain it at a safe level; and a means for selectively covering said large outlet opening wherein said means includes a body portion having a passageway therein wherein said passageway provides a small amount of continuous fluid communication between the atmosphere and said suction source and wherein said body portion is normally disposed to substantially restrict fluid communication through said large outlet opening and being movable to a non-restricting position in the event of failure of said diaphragm.