THE MANY ADVANTAGES of electronystagmographic (ENG) techniques in vestibular examination have been limited mainly to large medical centers and groups, predominately because of equipment costs and maintenance. Now, however, it is possible to obtain reasonably good measurements of eye motion with commercially available components costing less than $350, including postage.
Figures 1 and 2 show this equipment, some of the ENG tracings recorded with it, and the most essential specifications. For test purposes, we have used this equipment alongside our regular machine whose original cost exceeded $2,300. Within certain limits for high frequency response, the less expensive ENG apparatus performs just as adequately, and in some ways, slightly better. The tracings obtained are at least satisfactory for routine clinical use. This judgement is based upon experience with several hundred clinical ENGs obtained by state-of-the-art recording equipment.
The technically difficult steps in assembling this ENG apparatus have already been solved by