Patent US7373271B1 successfully refreshed from Google Patents.
US7373271B1
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System and method for measuring position and orientation using distortion-compensated magnetic fields
Assignee: Northern Digital Inc
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Filing: 2004-09-20
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Granted: 2008-05-13
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Expires: 2024-09-20
Abstract
Abstract An electromagnetic tracking system ( 600 ) and a distortion compensation method ( 500 ) that utilize a lead-lag network model to compensate for position and orientation distortion caused by eddy currents formed in one or more conductive distorters ( 330, 658 A-C) located within a tracking environment during electromagnetic tracking of one or more objects ( 612 ). the method is adaptive relative to the amount of distortion cause by the conductive distorters.
Inventors
- 👤 Mark R. Schneider
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:01
CPC Classifications
A; A61; A61B; A61B90/00; A61B90/36; A61B34/00; A61B34/20; A61B2034/2046; A61B2034/2051
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
129 words
A method of locating an object, comprising the steps of: a) generating at least one magnetic field; b) sensing said at least one magnetic field so as to generate at least one frequency response; c) representing said at least one frequency response in terms of at least one lead-lag network; and d) determining at least one of position and orientation of the object as a function of said at least one lead-lag network; wherein step c) comprises representing said at least one frequency response as a transfer function, H sensor (s), that is a function of parameters k, p j and z j , said transfer function being: H sensor ( s ) = k ∑ j s + z j s + p j .
Claim 2
Independent Claim
129 words
A method of locating an object, comprising the steps of: a) generating at least one magnetic field; b) sensing said at least one magnetic field so as to generate at least one frequency response; c) representing said at least one frequency response in terms of at least one lead-lag network; and d) determining at least one of position and orientation of the object as a function of said at least one lead-lag network; wherein step c) comprises representing said at least one frequency response as a transfer function, H sensor (s), that is a function of parameters k, p j and z j , said transfer function being: H sensor ( s ) = k ∑ j s + z j s + p j .
Claim 3
Dependent Claim
32 words
A method according to claim 1 , wherein step d) comprises collecting sufficient frequency response data so as to determine said parameters k, p j and z j in said transfer function.
Claim 4
Dependent Claim
25 words
A method according to claim 1 , wherein step d) comprises solving for said parameters k, p j and z j in said transfer function.
Claim 5
Dependent Claim
26 words
A method according to claim 1 , wherein step c) comprises representing said at least one frequency response in terms of at least two lead-lag networks.
Claim 6
Independent Claim
119 words
A method of locating an object, comprising the steps of: a) receiving at least one frequency response of at least one magnetic field sensor; b) representing said at least one frequency response in terms of at least one lead-lag network; and c) determining at least one of position and orientation of the object as a function of said at least one lead-lag network; wherein step b) comprises representing said at least one frequency response as a transfer function, H sensor (s), that is a function of parameters k, p j and z j , said transfer function being: H sensor ( s ) = k ∑ j s + z j s + p j .
Claim 7
Independent Claim
119 words
A method of locating an object, comprising the steps of: a) receiving at least one frequency response of at least one magnetic field sensor; b) representing said at least one frequency response in terms of at least one lead-lag network; and c) determining at least one of position and orientation of the object as a function of said at least one lead-lag network; wherein step b) comprises representing said at least one frequency response as a transfer function, H sensor (s), that is a function of parameters k, p j and z j , said transfer function being: H sensor ( s ) = k ∑ j s + z j s + p j .
Claim 8
Dependent Claim
32 words
A method according to claim 5 , wherein step c) comprises collecting sufficient frequency response data so as to determine said parameters k, p j and z j in said transfer function.
Claim 9
Dependent Claim
25 words
A method according to claim 5 , wherein step c) comprises solving for said parameters k, p j and z j in said transfer function.
Claim 10
Dependent Claim
26 words
A method according to claim 5 , wherein step b) comprises representing said at least one frequency response in terms of at least two lead-lag networks.
Claim 11
Dependent Claim
150 words
A computer readable medium containing computer instructions for determining the location of an object, said computer instructions comprising: a) a first set of instructions for receiving at least one frequency response of at least one magnetic field sensor; b) a second set of instructions for representing said at least one frequency response in terms of at least one lead-lag network; and c) a third set of instructions for determining at least one of position and orientation of the object as a function of said at least one lead-lag network; wherein said second set of instructions comprises instructions for representing said at least one frequency response as a transfer function, H sensor (s), that is a function of parameters k, p j and z j , said transfer function being: H sensor ( s ) = k ∑ j s + z j s + p j .
Claim 12
Dependent Claim
150 words
A computer readable medium containing computer instructions for determining the location of an object, said computer instructions comprising: a) a first set of instructions for receiving at least one frequency response of at least one magnetic field sensor; b) a second set of instructions for representing said at least one frequency response in terms of at least one lead-lag network; and c) a third set of instructions for determining at least one of position and orientation of the object as a function of said at least one lead-lag network; wherein said second set of instructions comprises instructions for representing said at least one frequency response as a transfer function, H sensor (s), that is a function of parameters k, p j and z j , said transfer function being: H sensor ( s ) = k ∑ j s + z j s + p j .
Claim 13
Dependent Claim
39 words
A computer readable medium according to claim 9 , wherein said third set of instructions comprises instructions for collecting sufficient frequency response data so as to determine said parameters k, p j and z j in said transfer function.
Claim 14
Dependent Claim
32 words
A computer readable medium according to claim 9 , wherein said third set of instructions comprises instructions for solving for said parameters k, p j and z j in said transfer function.
Claim 15
Dependent Claim
33 words
A computer readable medium according to claim 9 , wherein said second set of instructions comprises instructions for representing said at least one frequency response in terms of at least two lead-lag networks.
Claim 16
Independent Claim
144 words
A system for determining the location of an object, comprising: a) at least one magnetic field sensor; and b) a processor having an input operatively configured to receive at least one frequency response of said at least one magnetic field sensor, said processor operatively configured to: i) represent said at least one frequency response in terms of at least one lead-lag network; and ii) determine at least one of position and orientation of the object as a function of said at least one lead-lag network wherein said processor is operatively configured to represent said at least one frequency response as a transfer function, H sensor (s), that is a function of parameters k, p j and z j , said transfer function being: H sensor ( s ) = k ∑ j s + z j s + p j .
Claim 17
Independent Claim
144 words
A system for determining the location of an object, comprising: a) at least one magnetic field sensor; and b) a processor having an input operatively configured to receive at least one frequency response of said at least one magnetic field sensor, said processor operatively configured to: i) represent said at least one frequency response in terms of at least one lead-lag network; and ii) determine at least one of position and orientation of the object as a function of said at least one lead-lag network wherein said processor is operatively configured to represent said at least one frequency response as a transfer function, H sensor (s), that is a function of parameters k, p j and z j , said transfer function being: H sensor ( s ) = k ∑ j s + z j s + p j .
Claim 18
Dependent Claim
34 words
A system according to claim 13 , wherein said processor is operatively configured to collect sufficient frequency response so as to determine said parameters k, p j and z j in said transfer function.
Claim 19
Dependent Claim
28 words
A system according to claim 13 , wherein said processor is operatively configured to solve for said parameters k, p j and z j in said transfer function.
Claim 20
Dependent Claim
29 words
A system according to claim 13 , wherein said processor is operatively configured to represent said at least one frequency response in terms of at least two lead-lag networks.
Claim 21
Dependent Claim
19 words
A system according to claim 13 , further comprising a plurality of B-field generators and at least one sensor.
Claim 22
Dependent Claim
34 words
A system according to claim 13 , further comprising at least one B-field generator, said processor being further operatively configured to excite said at least one B-field generator in a time division multiplexed manner.
Claim 23
Dependent Claim
34 words
A system according to claim 13 , further comprising at least one B-field generator, said processor being further operatively configured to excite said at least one B-field generator in a frequency division multiplexed manner.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2011-05-13 | 2011-11-12 | 2012-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2015-05-13 | 2015-11-12 | 2016-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2019-05-13 | 2019-11-12 | 2020-05-13 | $7700.00 | Window Closed / Lapsed |