Patient valve incorporating one-way check valves for infection control

In patient valve for pulmonary test equipment of the type including a unitary hollow elastomeric body, said body including first, second, third and fourth tubular sections, each having an inner lumen, one end of each tubular section being joined and sealed in a common area to the other three tubular sections to allow fluid flow from any tubular section to any other tubular section without escaping from said body, said first and second tubular sections including zones in which said body is sufficiently elastic to close when squeezed and reopen when released, said first tubular section having its other end open to the ambient, said second tubular section adapted to be coupled to a patient mouthpiece, said third tubular section adapted to be coupled to a gas demand value and said fourth tubular section adapted to be coupled to a gas sampling chamber, the improvement comprising:

• infection control valve means disposed in said third and fourth tubular sections for allowing gas flow from said demand vale through said patient mouthpiece and blocking gas flow from said gas sampling chamber when the patient inhales through said mouthpiece and for permitting gas flow from said mouthpiece to said gas sampling chamber while blocking gas flow from said mouthpiece to said demand valve when the patient exhales through said mouthpiece.