A Constant Ratio Air-Oxygen Mixer

A new device has been developed which delivers regulated oxygen mixtures for use in respiratory therapy. The device is simple and compact for use at the bedside, and is compatible with all respirators and other gas delivery techniques. A single manual control allows selection of 100% oxygen or either of two intermediate mixture ratios. These mixtures are constant with changing ventilatory rates, and the system requires no monitoring or metering of the input gases.