Aerosol valves for medical purposes; apparatus for medical purposes; apparatus for medical use; apparatus for the control of medical gases; medical apparatus for assisting breathing; medical apparatus for the relief of pain; medical apparatus for use in respiration; medical inhalers; medical ventilators; respiratory apparatus for medical use; valves for use in medical infusion apparatus; inhalers; anaesthetic apparatus; medical pressure chambers; apparatus for administering drugs by inhalation; inhaler devices for administering medicaments; devices for use in the administration of medicines; devices for use in the administration of pharmaceuticals; drug delivery devices; inhalation devices for medical use; medical devices for assisting respiration; medical apparatus and instruments