A simple technique for thermal stimulation of single semicircular canals

Two simple thermodes for stimulating single semicircular canals have been designed in order to elicit eye nystagmus. The first, for warm stimulation, is based on the Joule effect: a silver needle is warmed up by means of a coiled nickrome wire. The temperature at the thermode tip is function of current intensity. The thermode for cold stimulation is a device in which a circulating freezing mixture cools a silver needle. The temperature at the thermode tip is proportional to the temperature of the freezing mixture.