Method and apparatus for locating passive integrated transponder tags
An apparatus for locating an embedded passive integrated transponder (PIT) tag is provided. An embodiment of the locating apparatus includes a resonator capable of electromagnetically coupling to the PIT tag, and a feedback circuit connected to the resonator and configured to monitor a load conductance of the resonator. A distance between the resonator and the PIT tag is indicated by a change in the monitored load conductance when the resonator and the PIT tag are electromagnetically coupled. Another embodiment includes a resonator capable of stimulating a response signal from a PIT tag, and a processing circuit capable of calculating the distance between the resonator and the PIT tag based on the amplitude of the response signal.
1. An apparatus comprising:
a handheld device configured to determine a location for insertion of a probe in a body, wherein the location is determined in response to movement of the handheld device outside the body to identify one or more tags within the body; and
a probe configured to move partially into an incision at the determined location of the body, the probe housing:
a coil located at a distal terminal end of the probe, the probe composed of a durable material with the distal terminal end configured for temporary insertion into the incision and movable towards the one or more tags embedded in tissue of the body while a proximal end of the probe remains outside of the tissue of the body, wherein the coil inserted within the tissue of the body via the incision is configured to transmit a radio frequency signal resonating at a low frequency towards the one or more tags within the body, each tag configured to energize from the radio frequency signal and transmit a unique identifier encoded;
wherein the apparatus determines position of the distal terminal end of the probe with reference to one or more tags within the body and provides an audible or visual indication of the determined position.
2. The apparatus of claim 1 , further comprising:
a depth calculation circuit configured to determine a distance between a particular tag within the body and the distal terminal end of the probe, the determination based at least on a signal received from the particular tag in response to receiving the low frequency signal transmitted from the coil.
3. The apparatus of claim 1 , wherein the position of the probe comprises a distance to one or more tags within the body.
4. The apparatus of claim 1 , wherein the position of the probe comprises a direction to one or more tags within the body.
5. The apparatus of claim 1 , wherein the low frequency signal transmitted from the coil is a continuous signal.
6. The apparatus of claim 1 , further comprising a switching circuit configured to adjust the resonant frequency of the coil.