Abstract: An oxygen consumption monitor system suitable for use in measuring oxygen uptake in neonates wherein the system includes a check valve system in combination with a high flow, positive-end-expiratory-pressure respirator for supplying a high volume, controlled flow of oxygen through a flow circuit which includes (1) a primary flow line for carrying most of the oxygen supply through a respirator circuit maintained at a positive pressure, and (2) a secondary outlet communicating from said primary flow line through the check valve combination to permit inspiration of oxygen from the respirator circuit and expiration to a separate chamber for measurement of oxygen consumption. Minimal deadspace is developed in the check valve combination to insure fresh oxygen supply with each inspiration by the neonate. The use of opposing oneway valves at inlet and outlet locations of the valve combination permits use of a single opening for coupling to an endotrachael tube.

Abstract: A device for continuously monitoring oxygen consumption and anesthesia gas uptake of surgical patients, having servo-controlled replenishment mechanisms to automatically maintain preset levels of oxygen and anesthesia gas for inhalation. A closed, recirculating delivery circuit is utilized to adminster an appropriate volume of oxygen and anesthesia gas to a surgical patient. An oxygen sensor monitors decreases in oxygen concentration within the recirculatory system and triggers restoration to the preset concentration by means of feedback comparator circuitry. With the oxygen held at the desired level, any volume changes in the system are caused by uptake of anesthesia gas, which is monitored by detecting variations in the expansion of a respirator bellows. The desired amount of anesthesia gas is preset and maintained by a potentiometric monitoring device which produces a voltage proportional to the peak expansion of the bellows.

Abstract: A chemical sensitive field-effect transistor transducer capable of selectively detecting and measuring chemical properties of substances to which the transducer is exposed. The transducer includes a semiconductor substrate material having a certain doping polarity, a pair of spaced apart diffusion regions located at the surface of the substrate material and having a doping polarity opposite that of the substrate material, electrical insulator material overlying the diffusion regions and the surface of the substrate material lying between the diffusion regions, and a chemical selective system overlying the insulator material. The chemical selective system is adapted to interact with certain substances and thereby modulate an electric field produced in the substrate material between the diffusion regions. This modulation is dependent upon the chemical properties of the substances and provides a measure of those chemical properties.