US Patent 6994087 Esophageal intubation detection system

An endotracheal tube bulb aspirator system has a bulb with a top end, a bottom end with an open bottom, and a transition zone therebetween. A first interior space in the top end is contiguous with a second interior space in the bottom end. At least one first flapper valve on the bulb includes at least one aperture in the bulb and an associated sheet positioned over the associated aperture with a portion of one edge being free. A second flapper valve is positioned adjacent the transitional zone between the first interior space and the second interior space has support beams and a disc with free edges coupled centrally to the support beams.