A precision optical element is described, such as is used in thermal imaging systems in the infra-red, manufactured by means of single point machining, with both of its surfaces having an aspheric form, with or without the addition of a diffractive optics pattern. The end result is achieved by integrating DC tracking, 3D reconstructions of pre-acquired patient scans and imaging software into a system enabling a physician to internally guide an instrument with real-time 3D vision for diagnostic and interventional purposes. The fluid to be atomised is therefore substantially atomised only in the inhalation phases. A subscriber to a subscription service specifies the set of subscriber-specified rules, and the set of subscriber-specified rules specifies how electronic data is formatted for the subscriber. Opposed louvers are included on at least one duct segment thereby regulating the temperature via forcing ambient air into the simulator. The device comprises an anchor having a cannula and a locking mechanism for securing the suture within the cannula.