Electronic temperature monitoring during the decompression surgery of the facial nerve.

Despite of its apparent protection by being located deep in a bony canal, the facial nerve is a cranial pair of nerves more vulnerable to traumatic injuries. The surgical accidents are the most frequent causes of intratemporal complications of the facial nerve. Among the postoperative sequelae, the thermal injuries are common due to overheating of the otologic burr resulting in facial paralysis. For the prevention of thermal injuries in the facial nerve was designed a data acquisition board to obtain the temperature measured by thermocouples using a PC and parallel communication. The signals from the temperature sensors passed through conditioning for amplification and analog to digital data conversion. Afterwards, they were stored on a computer for the statistical analysis and the visualization of the curves of variation of the measured temperatures. These curves provide the verification of the facial nerve temperature ascending and descending time during surgery steps to access the nerve. These data provide a substantial safe working margin to the surgeon.