A respiratory valve for rapid switching between two gas mixtures

We have devised a respiratory valve that facilitates rapid and silent breath-to-breath switching between two gas mixtures, under remote control. It utilizes two inspiratory Loven-type valve elements, one for each gas mixture, either of which can be held closed with an electromagnet. Any type of valve element can serve as the expiratory valve. We have used a small respiratory valve with goats and a larger model for both goat and human use.