Hand-held dual spherical antenna system

A method to detect surgical objects in a work area, the surgical objects marked by respective resonant tag elements that produce return signals in response to energization, the method comprising:

• providing a transponder detection device that includes a hand-held probe comprising a housing having a cavity therein;
• a first coil assembly and a second coil assembly received within the cavity of the housing spaced from each other, wherein each of the first and the second coil assemblies respectively includes:
• a substantially spherically shaped coil form that includes three coil support channels, each of the three coil support channels which define an outer coil support surface;
• a first antenna element comprising a first electrical conductor wound around the outer coil support surface of a first one of the three coil support channels, the first antenna element arranged to transmit and receive signals generally in a first coordinate direction;
• a second antenna element comprising a second electrical conductor wound around the outer coil support surface of a second one of the three coil support channels over the first electrical conductor, the second antenna element arranged to transmit and receive signals generally in a second coordinate direction orthogonal to the first coordinate direction;
• and a third antenna element comprising a third electrical conductor wound around the outer coil support surface of a third one of the three coil support channels over the first electrical conductor and the second electrical conductor, the third antenna element arranged to transmit and receive signals generally in a third coordinate direction orthogonal to the first coordinate direction and the second coordinate direction;
• emitting wideband interrogation signals via the respective first antenna elements, the second antenna elements and the third antenna elements of the first and the second coil assemblies;
• receiving any of the return signals from any of the resonant tag elements via at least one of the respective first antenna elements, the second antenna elements and the third antenna elements of the first and the second coil assemblies;
• and
• determining from a receipt of any of the return signals whether any of the resonant tag elements are present in the work area.