SYSTEM AND METHOD FOR MANEUVERING COILS POWER OPTIMIZATION

• US 20160175063A1
• Filed: 08/26/2014
• Published: 06/23/2016
• Est. Priority Date: 08/29/2013
• Status: Active Grant

• Current Assignee: Given Imaging Limited (Medtronic Plc)
• Original Assignee: Given Imaging Limited (Medtronic Plc)
• Inventors: HASON, Eshel, INBAR, Golan, PELEG, Dori
• Granted Patent: US 10,070,932 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 1/00006 of control signals
• CPC Class Codes: A61B 1/00036 Means for power saving, e.g. sleeping mode
• CPC Class Codes: A61B 1/00158 using magnetic field
• CPC Class Codes: A61B 1/041 Capsule endoscopes for imaging
• CPC Class Codes: A61B 34/73 Manipulators for magnetic surgery
• CPC Class Codes: A61B 5/062 using magnetic field

Abstract

An optimization unit controls electrical currents of a set of electromagnets to generate a wanted maneuvering magnetic field pattern (MMP) for moving an in-vivo device in the GI system. The optimization unit may calculate a magnetic force and a magnetic field to maneuver the in-vivo device from a current location and/or orientation to a new location and/or orientation. The optimization unit may solve a magnetic force optimization problem with respect to the magnetic force in order to determine electrical currents suitable for generating the wanted MMP. The optimization unit may additionally or alternatively solve a minimum electrical power optimization problem with respect to the electrical power to be consumed by the electromagnets in order to recalculate or adjust the electrical currents. The optimization unit may solve one or more of the optimization problems while complying with a set of constraints associated with or derived from each type of optimization objective.

Claims

1. A method for moving an in-vivo device in vivo, comprising:

in a magnetic system comprising a number N of electromagnets for generating a maneuvering magnetic field pattern to move a device in vivo,

(a) receiving data representative of a first set of magnetic field particulars calculated based on data representing a location and orientation of the in-vivo device;

(b) selecting, based on the location and orientation,

(b.1) one or more optimization objectives from;

(i) a minimum difference between a value or values of a second set of magnetic field particulars to be generated by the N electromagnets and respective value or values of the first magnetic field particulars, and

(ii) a minimum electrical power to be consumed by the electromagnets, and

(b.2) a set of constraints associated with or derived from a selected optimization objective and the first set of magnetic field particulars; and

(c) providing to the N electromagnets a set of electrical currents such that the second magnetic field particulars satisfy the selected optimization objective(s), and the selected set of constraints is complied with.

2. The method as in claim 1, wherein selecting a set of constraints comprises selecting one or more constraints from a group consisting of:

(a) a permissible value, or range, of the magnetic field (B);

(b) a permissible value, or range, of the magnetic force (F);

(c) a permissible value, or range, of the magnetic torque (T);

(d) a permissible value, or range, of a direction (α

) of the magnetic field;

(e) a permissible value, or range, of a direction (β

) of the magnetic force; and

(f) a permissible value or range of a ratio (R) between the magnetic field (B) and the magnetic force (F).

3. The method as in claim 1, wherein the location and orientation data comprises data representing a new location and orientation the in-vivo device is maneuvered to.

4. The method as in claim 1, wherein the data representing the location and orientation of the in-vivo device comprises data representing a current location and a current orientation of the in-vivo device.

5. The method as in claim 4, comprising calculating the first set of magnetic field particulars based on (i) the current location and orientation of the in-vivo device, or (ii) a new location and orientation of the in-vivo device, or (iii) both the current and new locations and orientations of the in-vivo device.

6. The method as in claim 1, wherein each of the first and second sets of magnetic field particulars comprises a magnetic field, a magnetic force and a magnetic torque.

7. The method as in claim 6, wherein a value of the magnetic force depends on a factor selected from a group of factors consisting of:

a location of the device in the gastrointestinal system and the velocity of the device in the gastrointestinal system.

10. The method as in claim 6, wherein a magnetic force applied to the in-vivo device is selected from a group consisting of:

(i) a maximum magnetic force (F_max) and (ii) a magnetic force which is less than the maximum magnetic force.

11. The method as in claim 6, comprising solving a force optimization problem for a calculated magnetic force to obtain a first set of electrical currents for the electromagnets.

12. The method as in claim 11, further comprising solving a minimum electrical power optimization problem to obtain a second set of electrical currents that can potentially drive the electromagnets.

13. The method as in claim 12, comprising deciding to solve, or to refrain from solving, the minimum electrical power optimization problem depending on:

(i) a region of the gastrointestinal tract the in-vivo device is at, or (ii) the magnitude of the magnetic force required to move the in-vivo device.

14. The method as in claim 12, comprising providing to the electromagnets the first set of electrical currents when no minimum electrical power optimization problem is to be solved, and the second set of electrical currents when the minimum electrical power optimization problem is solved.

15. The method as in claim 1, wherein calculating the electrical currents comprises:

(a) calculating a maneuvering vector ({right arrow over (V)}_ref) including a combination of magnetic field particulars of the maneuvering magnetic field pattern;

(b) calculating an initial set of N linear electrical currents ({right arrow over (I)}) that complies with the maneuvering vector ({right arrow over (V)}_ref) and results in minimal total electrical power (P_min);

(c) scaling down the initial N linear electrical currents ({right arrow over (I)}) by multiplying the initial N linear electrical currents ({right arrow over (I)}) by an electrical current correction factor α

;

(d) compensating the N scaled down linear electrical currents ({right arrow over (I)}) for non-linearity artifacts to obtain a set of N compensated electrical currents (Ĩ

);

(e) if a total electrical power (Pt) resulting from the N compensated electrical currents (Ĩ

) is equal to or greater than the maximum power threshold (P_max) performing,

(i) converting the N compensated electrical currents (Ĩ

) into N linear electrical currents;

(ii) multiplying the N linear electrical currents ({right arrow over (I)}) obtained at step (f)(i) by a power correction factor g (0<

g<

1), and

(iii) repeating steps (i) and (ii) iteratively until the total electrical power (Pt) resulting from the N compensated electrical currents is less than the maximum power (P_max) threshold; and

(f) generating the maneuvering magnetic field pattern using the N compensated electrical currents (Ĩ

) for which the resulting total electrical is less than the maximum power threshold (P_max).

16. The method as in claim 15, wherein the value of the electrical current correction factor α

is less than one when any current of the initial set of N linear electrical currents ({right arrow over (I)}) exceeds a predetermined respective maximum threshold value.

17. The method as in claim 15, comprising (i) calculating an electrical current correction factor α

for each linear electrical current and (ii) scaling down the N linear electrical currents using the electrical current correction factor α

having the minimal value.

8. (canceled)

9. (canceled)

18. A method for moving an in-vivo device in vivo, comprising:

receiving a first set of magnetic field data calculated from data representing a location and orientation of an in-vivo device;

selecting, based on the location and orientation of the in-vivo device, one or more optimization objectives from a group consisting of;

(i) a minimum difference between values of a second set of magnetic field data and values of the first magnetic field data, and (ii) a minimum electrical power for a set of electromagnets;

selecting a set of constraints associated with an optimization objective and the first set of magnetic field data; and

providing, to the electromagnets, electrical currents such that the second magnetic field data satisfies the optimization objective(s), and the selected set of constraints is complied with.

19. The method as in claim 18, comprising providing to the electromagnets a first set of electrical currents when the minimum electrical power optimization objective is not selected, and a second set of electrical currents when the minimum electrical power optimization objective is selected.

20. A magnetic system for maneuvering an in-vivo device in a gastrointestinal tract, comprising:

a number N of electromagnets positioned circularly and forming a plane; and

an optimization unit to control the electrical currents of the N electromagnets, the optimization unit configured to,

receive data representative of a first set of magnetic field particulars calculated based on data representing a location and orientation of the in-vivo device;

select, based on the location and orientation,

one or more optimization objectives from;

(i) a minimum difference between a value or values of a second set of magnetic field particulars to be generated by the N electromagnets and respective value or values of the first magnetic field particulars, and

(ii) a minimum electrical power to be consumed by the electromagnets, and

select a set of constraints associated with or derived from a selected optimization objective and the first set of magnetic field particulars; and

provide to the N electromagnets a set of electrical currents such that the second magnetic field particulars satisfy the selected optimization objective(s), and the selected set of constraints is complied with.

21. The system as in claim 20, wherein the optimization unit is configured to solve, for a given magnetic force, a magnetic force optimization problem to obtain a first set of electrical currents for the N electromagnets, and to solve a minimum electrical power optimization problem to obtain a second set of electrical currents for the N electromagnets.

22. The system as in claim 21, wherein the optimization unit is configured to provide to the electromagnets the first set of electrical currents when no minimum electrical power optimization problem is to be solved and the second set of electrical currents when the minimum electrical power optimization problem is solved.

23. The system as in claim 22, wherein the optimization unit is configured to solve, or to refrain from solving, the minimum electrical power optimization problem based on a decision depending on any of:

(i) a region of the gastrointestinal tract the in-vivo device is in and (ii) a magnitude of the magnetic force required to move the in-vivo device.