An apparatus for supplying one or more gases, such as oxygen, to a target area, comprising a top layer and a bottom layer sealed around the perimeter of the layers to form a reservoir between the layers, wherein the top layer is not gas-permeable and the bottom layer is highly gas-permeable, said reservoir...http://www.google.co.uk/patents/US7263814?utm_source=gb-gplus-sharePatent US7263814 - Method and apparatus for supplying gas to an area
