Described are oral phlegm extraction systems having a mouth insertion apparatus, a misting apparatus, and a suction apparatus. The mouth insertion apparatus includes a bite platform with at least one suction aperture positioned on a proximal end of the platform and directed toward an entrance to the patient's throat. A tongue positioner may also be included with at least one suction aperture positioned on a proximal end of the tongue positioner and directed toward an entrance to the patient's throat. The mouth insertion apparatus is also shaped to direct a flow of moist gas toward the entrance to the patient's throat.

A negative-pressure sputum suction device capable of intermittently sucking sputum includes a box body, an intermittent negative pressure mechanism, an atomization mechanism, a negative pressure pipe, a ventilation frame, a filter screen, a collection mechanism, a box door, an anti-skid leg and a conveying pipe; the intermittent negative pressure mechanism is arranged in the box body, the atomization mechanism is arranged in the box body, and the negative pressure pipe is fixedly connected to the box body; the ventilation frame is fixedly connected to the box body, the filter screen is fixedly connected to the ventilation frame, the collection mechanism is arranged on the outer side of the box body, and the box door is hinged to the box body; four evenly-distributed anti-skid legs are fixedly connected to the box body, and the conveying pipe is fixedly connected to the box body.