Surgical implement detector utilizing a powered marker

An apparatus for detecting a surgical implement in human or animal tissue, comprising:

• (a) a marker secured to a surgical implement adapted to be positioned within a surgical wound, said marker being battery powered and including a starting means having a receiver means for receiving a first signal and a switch connected to said battery for activating said marker;
• (b) field generating means for transmitting an electromagnetic field having a predetermined frequency band;
• (c) signal generating means activated by said starting means in response to receipt of a first signal to cause said field generating means to transmit said electromagnetic field, said electromagnetic field being a second signal that provides said marker with signal identity, and said starting means operating in response to said first signal to close said switch, connecting said signal generating means with said battery;
• (d) detection means having (i) an interrogator means for generating and transmitting said first signal to said starting means, (ii) a signal processor means for receiving said second signal and (iii) an antenna, said antenna being alternately connected to said interrogator means and said signal processor means for generating said first signal and receiving said second signal to detect said marker;
• (e) said field generating means consisting of a coil when said second signal has a frequency below 3 megahertz and comprising a single end lead when said second signal has a frequency above 3 megahertz;
• and
• (f) said antenna being a coil when said second signal has a frequency below 3 megahertz and comprising a single end lead when said second signal has a frequency above 3 megahertz.