Abstract: A heatless fractionating apparatus and method wherein a pressurized gaseous mixture, such as air, is alternately passed through first and second adsorbent beds for adsorbing at least a first component but not a second component of the gaseous mixture, and wherein each adsorbent bed is purged of the adsorbed component during the intervals in which the gaseous mixture is not passed through it. A valve system for each adsorbent bed comprises a pressure-responsive valve which responds to the delivery of the pressurized gaseous mixture through an electrically operated valve to deliver the gaseous mixture to its associated adsorbent bed. The pressure-responsive valve also operates to vent purge and other gases from its associated adsorbent bed when the electrically operated valve is closed to block delivery of the pressurized gaseous mixture to the pressure-responsive valve.

Abstract: Disclosed herein is a patient ventilator apparatus having a pneumatic control system operable in three different modes wherein the apparatus assists the breathing of the patient, controls the patient's breathing in a timed manner, or operates in a combination assist/control mode according to certain predetermined conditions. Fluidic circuitry controls a valved bellows apparatus, which in turn supplies air to a patient subject to limitations of time, volume, and pressure, wherein the gas supplied to the bellows comprises an adjustable oxygen/air mixture. Fluidic timers are provided for use in the control mode of the circuitry, and identical fluidic circuitry combinations are provided for use in the assist mode to automatically trigger the ventilator apparatus into an inspiratory state according to the patient's breathing requirements and to trigger such apparatus into an exhalation state when a predetermined inspiratory pressure is attained.