Patent ID: 6784826
Filing Date: 2004-08-31
Classification: A61B,G01S

Abstract:
A method for capturing the position and movement of a subject living body comprising the steps of:providing a transmitter (73); said transmitter (73) disposed on a subject (12) at a location to be tracked; said subject (12) moving from position-to-position within a volume of space (16); emitting a signal (40) from transmitter (73); providing a plurality of widely-spaced receiving antennas (76, 78) disposed at edges of said volume of space (16); measuring a phase difference (&Dgr;&phgr;1) of said signal (40) being received at each independent pair of said plurality of receiving antennas (76, 78) when said transmitter (73) is at a first position (72); changing a physical position of said transmitter (73) from a first position (72) to a second position (74); measuring a phase difference (&Dgr;&phgr;2) of said signal (40) being received at each said independent pair of said plurality of receiving antennas (76, 78) when said transmitter (73) is at a second position (74); and estimating a change in said physical position of said transmitter (73) by comparing measured phase differences (&Dgr;&phgr;1, &Dgr;â€ƒ2) of received said signal (40) at each said independent pair of said plurality of receiving antennas (76,78).