A MINIATURE WALK-AROUND OXYGEN REBREATHER DEVICE

An ultraminiature walk-around oxygen rebreather device has been developed. The total weight of the prototype model is only 1.5 pounds, and additional miniaturization which would be feasible with mass production would reduce the weight of the device still more. The device is completely self-contained in a mask and requires no connection either to an oxygen source or a CO2 remover. With a moderate work load the oxygen supply lasts one hour. In brief, the device consists of a rebreather bag, cannister of CO2 remover, and an oxygen source with appropriate pressure reduction and demand regulation. To reduce to a minimum the weight required and to improve the safety factor, the oxygen is stored in a tubing coiled around the small CO2 cannister. A newly designed pressure reducer supplies a modified miniature demand regulator such that oxygen is delivered to the breather on collapse of the rebreather bellows during inspiration. Since the breath passes through the CO2 absorber during both inspiration and expiration, the efficiency of the absorber is increased by the added contact time so that the amount of the absorber may be reduced. Author