Medical and surgical apparatus; surgical apparatus, namely, humidifiers for use in surgical and medical procedures; surgical or medical equipment for the purpose of delivering humidified gases; humidifiers and patient interface devices including diffusers, smoke evacuators, filters, adaptors, meters, humidification chambers; tubing connectors for medical or surgical use, tubing for medical or surgical use; drug or other substance delivery mechanisms for use during surgical or medical procedures; parts and fittings for all the aforementioned goods