Patent ID: 7358738
Filing Date: 2008-04-15
Classification: F16L,G01V

Abstract:
1. A marker locator, comprising: at least one transmitter channel coupled to provide a transmitter signal to an electromagnetic field generator, wherein the transmitter signal is phase shifted to provide a delay phase of substantially zero at the end of an electromagnetic pulse and is capable of exciting multiple types of markers; at least one receiver channel coupled to receive time decay signals from an electromagnetic field detector; and a digital processor coupled to provide digitized transmitter output signals to the at least one transmitter channel and to receive digitized time decay signals from the at least one receiver channel, wherein the digital processor receives the digitized time decay signals from the at least one receiver channel in the time interval between pulses of application of digitized transmitter output signals to the at least one transmitter channel, the averages the digitized time decay signals received from the at least one receiver channel, adapts the frequency of the averaged time decay signals, wherein the adapted frequency and the averaged time decay signals can assist in distinguishing between the multiple types of markers.