Patent ID: 6261247
Filing Date: 2001-07-17
Classification: A61B,G01B,G01S

Abstract:
A system for sensing relative positions of first and second points, comprising:first and second substantially spherical transponders, said first transponder disposed at the first point and said second transponder disposed at the second point and each of said first and second transponders including:communication circuitry for communicating between said first and second transponders, said first transponder transmitting a signal and said second transponder receiving the signal therefrom,distance determination circuitry for determining from the signal received a relative distance between said first and second transponders, anda transmitter for transmitting from said second transponder data relating to the relative distance determined by said second transponder to an external source; anda processing unit for receiving the data transmitted by said second transponder related to the relative distance data and processing that data to determine the relative positions.