Capnography apparatus; respiratory apparatus for use in surgery and intensive care; respiratory gas mixing apparatus for medical use; invasive and non-invasive ventilation apparatus and instruments; breathing tubes used in the delivery of air and gases to and away from patients; cannulae; nasal cannulae; cannula for respiratory purposes; sensor apparatus for medical use to detect gases; tubes for medical or surgical use; connectors for medical or surgical use; facial masks, oral masks, nasal masks, nasal interfaces, mouthpieces, all being for medical and surgical purposes; parts and fittings for all the aforementioned goods