High-gradient recursive locating system
First Claim
1. A method for locating a field probe, comprising the steps of:
- disposing a first group comprising a plurality of first field elements at known locations;
disposing a second group comprising a plurality of second field elements within an operational space of said first field elements;
disposing said field probe within an operational space of said second field elements, a first transmitting section being defined by one of a portion of said first group and a portion of said second group, a first receiving section being defined by another of said portion of said first group and a portion of said second group, wherein at least one of said first transmitting section and said first receiving section has at least two members, a second transmitting section being defined by one of said second group and said field probe, a second receiving section being defined by another of said second group and said field probe;
actuating said first transmitting section and said first receiving section to produce at least one first generated field;
making a first measurement of said first generated field in said first receiving section;
responsive to said first measurement calculating a first estimated location of each member of said first transmitting section relative to each member of said first receiving section;
actuating said second transmitting section and said second receiving section to produce at least one second generated field;
making a second measurement of said second generated field in said second receiving section;
responsive to said second measurement calculating a second estimated location of each member of said second transmitting section relative to each member of said second receiving section; and
using said first estimated location and said second estimated location to calculate a location of said field probe relative to said first field elements.
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Accused Products
Abstract
A system for tracking a probe within an area of operations such as a patient'"'"'s body comprises a set of primary radiators disposed at known locations. The primary radiators are driven by a control unit to track the positions of a plurality of secondary radiators with respect to the primary radiators. The secondary radiators are optionally movable, and are driven to track the position of the probe with respect to the secondary radiators. A calculation is performed to determine the corresponding position of the probe with respect to the fixed locations. Radiators at each level of the hierarchy generate fields that are locally optimized for detection by the next level of the hierarchy and for the minimization of interference by nearby metallic objects. The system is also capable of determining the angular alignment of the probe with respect to a known coordinate system.
344 Citations
54 Claims
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1. A method for locating a field probe, comprising the steps of:
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disposing a first group comprising a plurality of first field elements at known locations;
disposing a second group comprising a plurality of second field elements within an operational space of said first field elements;
disposing said field probe within an operational space of said second field elements, a first transmitting section being defined by one of a portion of said first group and a portion of said second group, a first receiving section being defined by another of said portion of said first group and a portion of said second group, wherein at least one of said first transmitting section and said first receiving section has at least two members, a second transmitting section being defined by one of said second group and said field probe, a second receiving section being defined by another of said second group and said field probe;
actuating said first transmitting section and said first receiving section to produce at least one first generated field;
making a first measurement of said first generated field in said first receiving section;
responsive to said first measurement calculating a first estimated location of each member of said first transmitting section relative to each member of said first receiving section;
actuating said second transmitting section and said second receiving section to produce at least one second generated field;
making a second measurement of said second generated field in said second receiving section;
responsive to said second measurement calculating a second estimated location of each member of said second transmitting section relative to each member of said second receiving section; and
using said first estimated location and said second estimated location to calculate a location of said field probe relative to said first field elements. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for locating a field probe, comprising the steps of:
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disposing a plurality of first field generating elements at known locations;
disposing a plurality of second field generating elements within an operational space of said first field generating elements;
disposing said field probe in an operational space of said second field generating elements;
energizing each of said second field generating elements and making first measurements of respective first generated fields thereof at said field probe;
responsive to said first measurements calculating a first position of said field probe relative to said second field generating elements;
energizing each of said first field generating elements, and making second measurements of respective second generated fields thereof in said second field generating elements;
responsive to said second measurements calculating respective second positions of said second field generating elements relative to said first field generating elements; and
using said first position and said second positions to calculate a location of said field probe relative to said known locations. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. An apparatus for locating an object, comprising:
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a plurality of first field generating elements disposed at known locations;
a plurality of second field generating elements disposed within an operational space of said first field generating elements;
a field probe attached to said object;
an energizer for energizing said first field generating elements and said second field generating elements in a desired sequence to generate respective first generated fields and second generated fields, wherein a first signal is generated by said field probe responsive to said second generated fields, and a second signal is generated by said second field generating elements responsive to said first generated fields; and
a calculator, coupled to receive and process said first signal so as to determine a first position of said field probe with respect to said second field generating elements, and to receive and process said second signal so as to determine second positions of said second field generating elements relative to said first field generating elements, and adapted to calculate a location of said object relative to said known locations based on said first position and said second positions. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28)
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29. A method for locating a field probe in a body of a living subject, comprising the steps of:
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disposing a plurality of first field elements at known locations, said first field elements being capable of sensing fields;
disposing a plurality of second field elements within an operational space of said first field elements, said second field elements being capable of generating fields, said first field elements and said second field elements being disposed external to said body;
disposing said field probe in an operational space of said second field elements inside said body, said field probe being capable of sensing fields;
energizing each of said second field elements and making first measurements of respective generated fields thereof at said field probe and making second measurements of said respective generated fields at each of said first field elements;
responsive to said first measurements calculating a first position of said field probe relative to said second field elements;
responsive to said second measurements calculating respective second positions of said second field elements relative to said first field elements; and
using said first position and said second positions to calculate a location of said field probe relative to said known locations. - View Dependent Claims (30, 31, 32, 33, 34, 35)
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36. A method for locating a field probe in a body of a living subject, wherein the field probe is a medical instrument having a sensor attached thereon, comprising the steps of:
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disposing a plurality of first field generating elements at known locations external to said body;
disposing a plurality of second field generating elements external to said body and within an operational space of said first field generating elements, said second field generating elements being capable of sensing fields;
disposing said field probe in an operational space of said second field generating elements inside said body;
energizing each of said second field generating elements and making first measurements of respective first generated fields thereof at said field probe;
responsive to said first measurements calculating a first position of said field probe relative to said second field generating elements;
energizing each of said first field generating elements, and making second measurements of respective second generated fields thereof in said second field generating elements;
responsive to said second measurements calculating respective second positions of said second field generating elements relative to said first field generating elements; and
using said first position and said second positions to calculate a location of said field probe relative to said known locations. - View Dependent Claims (37, 38, 39, 40, 41, 42, 43, 44)
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45. An apparatus for locating an object within a body of a living subject, comprising:
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a plurality of first field generating elements disposed at known locations external to said body;
a plurality of second field generating elements disposed external to said body and within an operational space of said first field generating elements;
a field sensor attached to said object;
an energizer for energizing said first field generating elements and said second field generating elements in a desired sequence to generate respective first generated fields and second generated fields, wherein a first signal is generated by said field sensor responsive to said second generated fields, and a second signal is generated by said second field generating elements responsive to said first generated fields; and
a calculator, coupled to receive and process said first signal so as to determine a first position of said field sensor with respect to said second field generating elements, and to receive and process said second signal so as to determine second positions of said second field generating elements relative to said first field generating elements, and adapted to calculate a location of said object inside said body relative to said known locations based on said first position and said second positions. - View Dependent Claims (46, 47, 48, 49, 50, 51, 52, 53, 54)
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Specification