Negative inspiratory force manometer apparatus

摘要

The apparatus is connected by tubing to a patient. The apparatus has a manometer on one side in communication with an entrance port conveying ambient air to the patient. A spring loaded cap is depressed to block air inspired by the patient and cause such air to move a diaphragm in the manometer so that the inspired negative air pressure of the patient can be recorded. As soon as the cap is released a spring opens the entrance port to continue normal flow of ambient air to the patient.