Method for safely and efficiently navigating magnetic devices in the body
First Claim
1. A method of turning a magnet element at an operating point inside 2 patients body from an initial direction to a desired final direction by moving a source magnet outside 2 patients body, the method comprising the steps of:
- determining a series of movements of the source magnet to turn the magnetic element to successively align with a series of target directions including at least one intermediate direction between the initial direction and the desired final direction, such that the direction of the magnetic element during each movement of the source magnet in the series does not deviate from the plane of the initial direction and the desired final direction by more than a predetermined amount; and
implementing the determined movements of the source magnet in series to turn the magnetic element from the initial direction to the final direction through the at least one intermediate direction.
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Accused Products
Abstract
A method of turning a medical device, having a magnetically responsive element associated with its distal end, at an operating point within an operating region inside a patient'"'"'s body from an initial direction to a desired final direction, through the movement of at least one external source magnet. The at least one external source magnet is moved in such a way as to change the direction of the distal end of the magnetic medical device from the initial direction to the desired final direction without substantial deviation from the plane containing the initial direction and the desired final direction.
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Citations
27 Claims
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1. A method of turning a magnet element at an operating point inside 2 patients body from an initial direction to a desired final direction by moving a source magnet outside 2 patients body, the method comprising the steps of:
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determining a series of movements of the source magnet to turn the magnetic element to successively align with a series of target directions including at least one intermediate direction between the initial direction and the desired final direction, such that the direction of the magnetic element during each movement of the source magnet in the series does not deviate from the plane of the initial direction and the desired final direction by more than a predetermined amount; and
implementing the determined movements of the source magnet in series to turn the magnetic element from the initial direction to the final direction through the at least one intermediate direction. - View Dependent Claims (2)
(a) selecting an initial series of target directions;
(b) determining the magnet movements needed to apply a magnetic field to turn the magnetic element to the target directions from their respective prior directions, and testing whether such movement causes the direction of the magnetic element to deviate from the plane of the initial direction and the final desired direction by more than a predetermined amount, and if so, selecting new and/or additional intermediate directions for the series of target directions;
(c) repeating step (b) until series of target directions and corresponding magnet movements have been determined that do not cause the direction of the magnetic element to deviate from the plane of the initial target direction by more than a predetermined amount.
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3. A method of turning a magnet element at an operating point inside a patient'"'"'s body from an initial direction to a desired final direction by moving a source magnet outside the body, the method comprising the steps of:
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(a) providing means for determining and maintaining during a procedure the location and orientation of the magnet element relative to the location and orientation of the external source magnet;
(b) choosing desired field vectors in the patient frame as a series of angularly spaced vectors which lie in the plane of the initial and final vectors and entering them in a processor;
(c) entering the position and direction of the vectors into a processor by a means of specifying and displaying the field and communicating with the processor;
(d) calculating field directions at the operating point in the reference frame of the patient by translating the desired vectors into the reference frame of the magnet;
(e) transforming each one of the sequence of vectors into the reference frame of the source magnet;
(f) calculating a surface of constant field strength of desired value in the magnet frame;
(g) locating each of the field vectors on the appropriate latitude of the surface of constant field strength corresponding to the correct transformed direction of the field vector;
(h) for each pair of sequential vectors of the total set, calculating the minimum motion of the source magnet required to change the field direction, taking advantage of the azimuthal symmetry of the magnet field; and
(i) executing the desired step turns by articulating the source magnet. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification