Method and apparatus for determining position of object
First Claim
Patent Images
1. Apparatus for determining the position of an object comprising:
- (a) a plurality of magnetic field generating coils for generating a plurality of different magnetic fields in a sensing volume, said coils being arranged in a stacked, overlapping group such that the sensing volume is positioned on one side of said overlapping group of coils taken together and not between any of said coils;
(b) control means for actuating said coils to generate said magnetic fields in a predetermined sequence,(c) a sensor connected to the object and movable within said sensing volume, and adapted to detect magnetic field components in at least two different local directions relative to the sensor, and(d) calculation means for determining the position of said sensor from the magnetic field components detected by said sensor during generation of said magnetic fields.
2 Assignments
0 Petitions
Accused Products
Abstract
Apparatus for determining the position of a probe in a sensing volume includes a plurality of magnetic field generating sources for generating different magnetic fields in the sensing volume, where the sources have a planar configuration and are positioned so that they at least partially overlap one another in horizontal extent and so that the sensing volume extends outwardly from the sources. The probe is provided with sensors which detect magnetic field components of fields generated by the sources. The position of the probe can be determined from the detected magnetic components. Methods for determining the probe position are also included.
-
Citations
21 Claims
-
1. Apparatus for determining the position of an object comprising:
-
(a) a plurality of magnetic field generating coils for generating a plurality of different magnetic fields in a sensing volume, said coils being arranged in a stacked, overlapping group such that the sensing volume is positioned on one side of said overlapping group of coils taken together and not between any of said coils; (b) control means for actuating said coils to generate said magnetic fields in a predetermined sequence, (c) a sensor connected to the object and movable within said sensing volume, and adapted to detect magnetic field components in at least two different local directions relative to the sensor, and (d) calculation means for determining the position of said sensor from the magnetic field components detected by said sensor during generation of said magnetic fields. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. Apparatus for determining the position of an object comprising:
-
(a) a plurality of magnetic field generating coils for generating a plurality of different magnetic fields in a sensing volume, said coils being arranged in a stacked, overlapping group such that the sensing volume is positioned on one side of said overlapping group of coils taken together and not between any of said coils, each of said coils including conductors encompassing an enclosed area, said coils being positioned so that said enclosed areas of said coils at least partially overlap one another in horizontal extent and define an overlap area, said overlap area encompassing at least about fifty percent of the enclosed area of each of said coils; (b) control means for actuating said coils to generate said magnetic fields in a predetermined sequence; (c) a sensor connected to the object and movable within said sensing volume, said sensor adapted to detect magnetic field components in at least two different local directions relative to the sensor; and (d) calculation means for determining the position of said sensor from the magnetic field components detected by said sensor during generation of said magnetic fields.
-
-
16. A method of determining the position of an object within a sensing volume comprising the steps of:
-
(a) actuating a plurality of magnetic field-generating coils arranged in a stacked, overlapping group to generate a plurality of magnetic fields in a predetermined sequence such that at least two of said coils generate fields varying quasi-linearly with position within near-field volumes, the near-field volumes of said coils intersecting one another within a sensing volume positioned on one side of said overlapping group of coils taken together and not between any of said coils; (b) measuring magnetic field components in the sensing volume above the near-field areas of said coils in at least two different local directions relative to a sensor connected to the object during generation of said fields; and (c) determining the position of said sensor from said magnetic field components detected during generation of said magnetic fields. - View Dependent Claims (17, 18)
-
-
19. A method of determining the position of an object within a sensing volume comprising the steps of:
-
(a) generating a plurality of different magnetic fields in a predetermined sequence in the sensing volume from a plurality of magnetic field generating coils arranged in a stacked, overlapping group such that the sensing volume is positioned on one side of said overlapping group of coils taken together and not between any of said coils; (b) measuring magnetic field components of said magnetic fields generated from said plurality of coils in at least two different local directions relative to a sensor connected to the object during generation of said fields; and (c) determining the position of said sensor from said magnetic field components detected during generation of said magnetic fields.
-
-
20. A method of determining the position of an object within a sensing volume comprising the steps of:
-
(a) generating a plurality of different magnetic fields in a predetermined sequence in the sensing volume from a plurality of magnetic field generating coils arranged in a stacked, overlapping group such that the sensing volume is positioned on one side of said overlapping group of coils taken together and not between any of said coils; (b) generating one or more magnetic dipole fields within said sensing volume; (c) measuring magnetic field components of said generated magnetic fields in at least two different local directions relative to a sensor connected to the object during generation of said fields; and (d) determining the position of said object from the magnetic field components detected during generation of said magnetic fields.
-
-
21. Apparatus for generating magnetic fields inside the body of a patient, comprising a plurality of magnetic field generating coils for generating a plurality of different magnetic fields in a sensing volume, said coils being arranged in a stacked, overlapping group such that the sensing volume is positioned on one side of said overlapping group of coils taken together and not between any of said coils.
Specification