Positive end expiratory pressure device

Positive end pressure valve apparatus comprising:

• (a) a flexible diaphragm;
• (b) housing means forming a chamber therein, said chamber being divided into segments by said diaphragm, said housing having an inlet port and an exhaust port penetrating a first one of said segments, said exhaust port being defined by a hollow protuberance into said first segment opening against said diaphragm in an undeflected condition;
• and
• (c) piston and cylinder means communicating with said housing means into the second of said segments, said cylinder being closed at one end and opening directly into said second segment at its other end, said piston travelling within said cylinder between said diaphragm and said one end, and having an elongated, hollow, cylindrical configuration, open facing said one end and closed but for a port at the end opposite said one end, said port connecting said second segment with the interior of said piston, said piston and said cylinder having predetermined clearance for further communication of said second segment with the interior of said piston, said diaphragm and said piston offering predetermined force to pressure at said inlet port by air compression and flow within and between said second segment and said piston and cylinder means;
• (d) whereby pressure exerted at said inlet port deflects said diaphragm and displaces said piston in opposition to said pressure exerted, creating a discontinuity between said diaphragm and said protuberance for exhaust flow between said inlet and exhaust ports.