Hand-held spherical antenna system to detect transponder tagged objects, for example during surgery

An interrogation and detection system, comprising:

• a processor;
• and
• a memory, including instructions stored thereon, which when executed by the processor cause the system to:
• control each of a first antenna element, a second antenna element, and a third antenna element of a spherical hand-held antenna, each of the first, second, and third antenna elements is a coil orthogonal to the other antenna elements, and a hollow interior to emit wideband interrogation signals in time-wise succession during a transmit portion of respective transmit and detection cycles;
• receive an electromagnetic signal during a noise detection portion of a detection cycle of the respective transmit and detection cycles;
• determine a noise value during the detection cycle that is indicative of a noise level corresponding to a highest of N samples of the received electromagnetic signal, wherein N is a positive number;
• and
• adjust a signal detection threshold based at least in part on the noise value of the detection cycle.

A non-transitory computer-readable storage medium which stores a program causing a computer to execute a computer-implemented method of operating an interrogation and detection system, the computer-implemented method comprising:

• controlling each of a first antenna element, a second antenna element, and a third antenna element of a spherical hand-held antenna including three orthogonal coils and a hollow interior to emit wideband interrogation signals in time-wise succession during a transmit portion of respective transmit and detection cycles;
• receiving an electromagnetic signal during a noise detection portion of a detection cycle of the respective transit and detection cycles, by a spherical hand-held antenna including three orthogonal coils and a hollow interior;
• determining a noise value during the detection cycle that is indicative of a noise level corresponding to a highest of N samples of the received electromagnetic signal, wherein N is a positive number;
• and
• adjusting a signal detection threshold based at least in part on the noise value of the detection cycle.