A device to visually indicate the presence of electric fields in
electrosurgical apparatus, without the necessity of wiring or an
electrical connection to the apparatus, to visually annunciate when an
electrosurgical instrument is active is disclosed. This is to alert the
operating surgeon, and observing personnel, that the device is
operational to mitigate the possibility of anyone inadvertently being
injured. The device is comprised of an electrically insulated enclosure
filled with a gas in close proximity to a surgical handpiece connected to
a radio frequency current generator.