An apparatus for monitoring the activity of a surgeon. At least one wireless sensing unit is provided for monitoring potential damage to a nerve and is located at a first location of a body being operated on by a surgeon. The wireless sensing unit senses a change in the body at the first location resulting from potential damage to the nerve occurring at a second location of the body remote from the first location. The wireless sensing unit produces a wireless sensed change output signal indicative of the change in the body which is received by a receiver and generates a corresponding received output signal. An analyzer unit receives and analyzes the received output signal to determine the change in the body. An indicator responsive to the output of said analyzer unit indicates the change in the body to indicate the potential damage to the nerve the surgeon.