Abstract: A system for monitoring a patient's EEG output comprises an EEG recorder operative to generate an EEG output indicative of electrical activity produced by the brain of a patient, and an auxiliary recorder operative to generate an auxiliary output indicative of another characteristic of the patient. The auxiliary recorder may comprise a video recorder. An electronic data processor is operative to receive the EEG recorder output and the auxiliary output, the system being operative to generate synchronisation data indicative of when the EEG output and when the auxiliary output occurred with reference to a datum signal. The electronic processor is operative to process the synchronisation data to subsequently synchronise the playback of the EEG output with the auxiliary output. A compensation factor accounts for transmission latency.

Abstract: A mask assembly for allowing application of gases to the nose and mouth of a person, the mask assembly including a gas delivery nozzle, a mask adapted to cover the nose and mouth of the person, and a retaining strap, the gas nozzle having one end connected to the mask and a free end adapted for connection to a connector assembly, the retaining strap including a clip member and a strap, the strap being adapted to extend around the back of the head of the person and having one end connected to one side of the mask and a free end, the clip member including first and second parts, one of the parts being attached to the free end of the strap and the other one of the parts being attached to the other side of the mask, a specified one of the first and second parts having first and second longitudinally spaced opposite ends, being attached to the mask or strap, respectively, at the first end and adapted for connecting the other of the parts thereto at different selected positions along its length, so that the effecti