Method and apparatus for refinably accurate localization of devices and instruments in scattering environments
AssigneeStereotaxis, Inc.
InventorRaju R. Viswanathan
Life of this patent
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Abstract
A method of localizing a device, medical or otherwise, within a three dimensional environment, the method comprising: (a) transmitting time varying magnetic fields from at least three transmitters, (b) receiving the transmitted electromagnetic radiation as induced voltage signals from at least one receiver mounted on or within said device, and (c) a processing scheme for processing said received voltage signals in order to extract position and orientation localization information for said device, said processing scheme including correction for conducting materials in the vicinity by the use of information gathered from at least three distinct transmission frequencies for each of said transmitters.
Claims23
A method of localizing a device, medical or otherwise, within a three dimensional environment, the method comprising:
- (a) transmitting time varying magnetic fields from at least three transmitters, (b) receiving the transmitted electromagnetic radiation as induced voltage signals from at least one receiver mounted on or within said device, and (c) processing said received voltage signals in order to extract position and orientation localization information for said device, said processing including correction for conducting materials in the vicinity by the use of information gathered from at least three distinct transmission frequencies for each of said transmitters.
A method for processing signals received by a receiver at multiple frequencies from each of a number of transmitters, where said processing includes, for each pair of receiver and transmitter:
- (a) producing polynomial fits of given order to the signal as a function of frequency, (b) said polynomial fit produced by a fitting procedure, weighted or otherwise, that in the case of a weighted procedure may employ different weights for different frequencies in order to improve the fit over desired frequency ranges, and (c) extracting the coefficient of the linear term in the polynomial fit as the flux in the receiver produced by each said transmitter.
A system for generating, acquiring and processing signals for the purpose of localizing position and orientation of a device in three dimensional space by electromagnetic means, said system comprising:
- (a) a main computer and programmable interface for refining the accuracy of localization estimation by signal generation, acquisition and processing, (b) a microprocessor controlled signal generation system linked to said main computer for driving a set of transmitters at a multiplicity of frequencies in various time and frequency multiplexed fashion, (c) a set of at least three transmitters located at known fixed locations and orientations in three dimensional space, (d) at least one receiver mounted on or within the device at which location position and orientation is desired to be found, (e) phase shifting and demodulation circuitry and/or digital signal processing software, and (f) processing software for producing polynomial fits to the signal over a range of frequencies over which signals are transmitted and received by said respective coils at discrete frequencies numbering at least three.
Dependencies are inferred from the claim text.