A low-cost method for simultaneous video-recording of ambulant subject and electroencephalograph: the Quarrier's system.

A system is described by means of which the ambulant subject may be video-filmed over several hours with the electroencephalograph superimposed on the same tape, allowing correlations to be observed in the active state. Our first subjects have been girls with Rett syndrome. Requirements are: one portable video camera/recorder, a conventional e.e.g. machine, the 'Medilog 9000' system for prolonged ambulatory recording (Oxford Medical), a specialized video mixer (videogram ForA FVG600, commercially available) a video timer, a conventional video cassette recorder and a television monitor. The cost is small for a department already equipped to carry out ordinary ambulatory e.e.g. monitoring. The method is safe, well tolerated, simple to use and adaptable. To the best of the authors' knowledge, they are the first to use this system and they believe that it should find wider application when it is desirable to correlate the behaviour of a subject with physiological parameters, on a restricted budget.