Trajectory-based deep-brain stereotactic transcranial magnetic stimulation

• US 20070260107A1
• Filed: 05/05/2006
• Published: 11/08/2007
• Est. Priority Date: 05/05/2006
• Status: Active Grant

• Current Assignee: US Department of Veterans Affairs (Government of the United States of America), Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Mishelevich, David, Schneider, M.
• Granted Patent: US 8,052,591 B2
• Time in Patent Office: Days
• US Class Current: 600/14
• CPC Class Codes: A61N 2/004 specially adapted for a specific therapy
• CPC Class Codes: A61N 2/006 for magnetic stimulation of nerve tissue
• CPC Class Codes: A61N 2/008 for pain treatment or analgesia
• CPC Class Codes: A61N 2/02 using magnetic fields produced by coils, including single turn loops or electromagnets A61N2/12 takes precedence

Abstract

The present invention provides for Stereotactic Transcranial Magnetic Stimulation (sTMS) at predetermined locations with the brain or spinal cord and incorporates an array of electromagnets arranged in a specified configuration where selected coils in the array are pulsed simultaneously. Activation of foci demonstrated by functional MRI or other imaging techniques can be used to locate the neural region affected. Imaging techniques can also be utilized to determine the location of the designated targets.

Claims

1. A method for generating magnetic-field stimulation at a target position in neural tissue comprising the steps of:

selecting a target position in neural tissue,

providing an array of electromagnets, and orienting the electromagnets to deliver magnetic-field energy components to the target position; and

simultaneously energizing at least two of the electromagnets, whereby a stimulating vector component of the magnetic field received at the target position is greater than that received by locations more proximal to the electromagnets.

2. The method of claim 1, wherein the orienting step includes orienting the electromagnets such that, during the energizing step, radial components of energy emitted by at least two of the energized electromagnets intersect at the target.

3. The method of claim 1, wherein the orienting step includes orienting the electromagnets such that, during the energizing step, radial components of energy emitted by at least three of the energized electromagnets intersect at the target.

4. The method of claim 1, wherein the energizing step includes the step of energizing at least two of the coils using different magnitudes of power.

5. The method of claim 1, wherein the energizing step includes the step of energizing at least two of the coils using current of opposite polarity.

6. The method of claim 1, in which the stimulating vector component is comprised of energy emitted from a plurality of the coils.

7. The method of claim 1, further including the step of moving the array during the energizing step.

8. The method of claim 1, further including the step of, during the energizing step, automatically moving the array along multiple axes.

9. The method of claim 1, including the step of moving at least one of the coils longitudinally and angularly relative to a target structure.

10. The method of claim 1, further including the step of reciprocating the coils along an axis perpendicular to a radial component of the magnetic field of one of the coils.

11. The method of claim 1, wherein the energizing step includes energizing the coils according to a pulse pattern, and wherein the method further includes interrupting the pulse pattern and then resuming the pulse pattern after an interval of time.

12. The method of claim 1, in which the orienting step positions at least two coils within a plane, and at least one coil outside the plane.

13. The method of claim 1, where the magnetic field further causes stimulation of neural tissue, said stimulation of neural tissue generating electrical signals, and wherein the effect of the stimulating vector component on the target is augmented by the electrical signals.

14. The method in claim 1, wherein each coil produces energy having a radial component, and wherein the orienting step includes orienting at least two of coils such that the radial component from a first one of the two coils occupies a first plane and the radial component from a second one of the two coils occupies a second plane that is different from the first plane.

15. The method of claim 14, in which the first and second planes are at arbitrary angles relative to one another.

16. The method in claim 1, where the target position is determined using imaging of the brain.

17. The method of claim 16, wherein the imaging step is carried out using functional MRI.

18. The method in claim 1, wherein the energizing step includes the step energizing at a first one of the coils at a first pulse frequency and energizing a second one of the coils at a second, different pulse frequency.

19. The method in claim 1, wherein the energizing step includes the step energizing at a first one of the coils at a first pulse pattern and energizing a second one of the coils at a second, different pulse pattern.

20. The method in claim 1, wherein the method further includes the steps of selecting a second target position, and wherein the energizing step results in stimulation at the second target position.

21. The method in claim 1, where the energization step causes the coils to emit patterns of pulses.

22. The method of claim 1, wherein stimulation of the target treats a condition in the patient, the condition selected from the group of conditions consisting of depression, chronic pain, Alzheimer'"'"'s Disease, obsessive compulsive disorder, addictions, obesity, and Parkinson'"'"'s Disease.

23. A method for predicting displacement of an energy field in a region of a stimulation target, comprising the steps of:

providing at least two data sets selecting from the data sets consisting of a first data set representing representing a calculated magnetic field strength distribution generated by a magnetic array;

a second data set representing a three dimensional location of a stimulation target in a brain, and

a third data set representing the propensity of the stimulation target to convert magnetic field into electric field; and

registering at least two of the data sets on a three-dimensional coordinate system to create a registered data set.

24. The method of claim 23, wherein the method is further for selecting an orientation of the magnetic array, and wherein the method further includes the step of determining from the registered data an orientation of the magnetic array most likely to cause stimulation of the stimulation target.

25. A neuromodulation system, comprising:

an array of a plurality of electromagnets positionable in proximity to a brain having a predetermined target;

a power supply for energizing at least two of the electromagnets to cause the array to produce a composite magnetic field comprised of magnetic field components of each energized coil, the coils oriented relative to one another such that when energized, the strength of the composite magnetic field will be greatest at the target.

26. The system of claim 25, wherein the array includes three electromagnets separated by 90-degree angles.

27. The system of claim 25, the array includes four electromagnets separated by 90-degree angles.

28. The system of claim 25, wherein the electromagnets in the array are arranged such that three of the electromagnets have radial components lying within a first plane, and wherein the fourth electromagnet has a radial component lying in a second plane intersecting the first plane.

29. The system of claim 25, wherein the array includes five electromagnets separated by 45-degree angles.

30. The system of claim 25, wherein the electromagnets are separated by unequal angles of separation.

31. The system of claim 25, further including a frame, wherein the array is coupled to the frame.

32. The system of claim 25, wherein the electromagnets have radial components in the plane of the frame.

33. The system of claim 25, wherein the electromagnets have radial components angled relative to the plane of the frame.

34. The system of claim 25, wherein the radial components of the electromagnets lie in a plane, and wherein the plane is angled relative to a horizontal plane.

35. The system of claim 25, where the electromagnets are selected from the group consisting of double coils, figure eight coils, and butterfly coils.

36. The system of claim 25, wherein at least two of the electromagnets in the array differ in shape from one another.

37. The system of claim 25, wherein electromagnets are arranged such that energization of the electromagnets will cause radial components of energy emitted by at least two of the electromagnets to intersect at a target.

38. The system of claim 25, wherein electromagnets are arranged such that energization of the electromagnets will cause radial components of energy emitted by at least three of the electromagnets to intersect at a target.