An electromagnetic valve for inspiratory occlusion pressures.

An electromagnetically powered respiratory valve to occlude a respiratory circuit for short (30--300ms) periods of the respiratory cycle may be inexpensively constructed from available laboratory instruments and controlled by an electronic circuit. Occlusion of the inspiratory breathing circuit may be repeated at different levels of ventilation without altering slopes or intercepts of CO2 rebreathing curves. The early phases of airway occlusion (P0.1) may therefore be studied in conscious unanesthetized human subjects.