A HUMAN NECESSITIES
A61 MEDICAL OR VETERINARY SCIENCE; HYGIENE
A61M DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
A61M2205/00 General characteristics of the apparatus
A61M2205/7536 allowing gas passage, but preventing liquid passage, e.g. liquophobic, hydrophobic, water-repellent membranes