1
Ernest B Blood: Device for quantitatively measuring the relative position and orientation of two bodies in the presence of metals utilizing direct current magnetic fields. Ascension Technology Corporation, Davis Bujold & Streck, July 31, 1990: US04945305 (472 worldwide citation)

A device for measuring the position (location and orientation), in the six degrees of freedom of receiving antennae (3) with respect to transmitting antennae (2) utilizing pulsed DC magnetic signals. The transmitting and receiving components consist of two or more transmitting antennae of known loca ...


2
Ernest B Blood: Device for quantitatively measuring the relative position and orientation of two bodies in the presence of metals utilizing direct current magnetic fields. Ascension Technology Corporation, Anthony G M Davis, Michael J Bujold, John J Welch Jr, July 18, 1989: US04849692 (330 worldwide citation)

A device for quantitatively measuring the relative position and orientation of two bodies in the presence of metals via measuring the position and orientation of receiving antennae with respect to transmitting antennae utilizing direct current electromagnetic field signals is hereby disclosed. The t ...


3
Ernest B Blood: Three dimensional digitizer with electromagnetic coupling. McDonnell Douglas Corporation, Price Heneveld Huizenga & Cooper, September 23, 1986: US04613866 (239 worldwide citation)

A three dimensional digitizer is provided for determining and digitizing the coordinates of a three dimensional object. A hand-held stylus is used for tracing and determining points of interest on the surface of the object. A plurality of antennas for radiating electromagnetic energy are provided, t ...


4
Ernest B Blood: Device for measuring position and orientation using non-dipole magnet IC fields. Ascension Technology Corporation, Davis and Bujold, February 4, 1997: US05600330 (235 worldwide citation)

Position and orientation of receiving antennae with respect to magnetic field transmitting antennae are determined. The transmitter consists of two or more antenna whose dimensions are large compared to the distance to the receiver. The receiver consists of two or more antenna that are sensitive to ...