A detection device for detecting X rays and signaling the detection to a computer-assisted surgery processor system comprises an X ray detector unit having an X ray detector adapted to be positioned within a radiation field. The X ray detector emits a detection signal upon being excited by an X ray of a given intensity. A transmitter outputs the detection signal in radio frequency. A receiver receives the detection signal in radio frequency and forwards the detection signal to a computer-assisted surgery processor system to signal the detection of the X ray. A method is provided as well.
