In one embodiment, a custom-fitted mask includes a thin sheet of deformable material that has been formed and fitted to a portion of a face surrounding the nostrils to conform substantially optimally to unique facial features. The thin sheet includes a perimeter defining only soft cartilaginous portions...http://www.google.fr/patents/US7963284?utm_source=gb-gplus-shareBrevet US7963284 - Custom fitted mask and method of forming same
