DISPLAY OF MODELED MAGNETIC FIELDS

• US 20110004450A1
• Filed: 10/09/2008
• Published: 01/06/2011
• Est. Priority Date: 10/09/2007
• Status: Active Grant

• Current Assignee: Brainsway, Ltd.
• Original Assignee: Cervel Neurotech, Inc.
• Inventors: Schneider, M. Bret, Mishelevich, David J.
• Granted Patent: US 8,265,910 B2
• Time in Patent Office: Days
• US Class Current: 703/2
• CPC Class Codes: A61N 2/006 for magnetic stimulation of nerve tissue
• CPC Class Codes: A61N 2/02 using magnetic fields produced by coils, including single turn loops or electromagnets A61N2/12 takes precedence

Abstract

Methods and systems for modeling and displaying magnetic field intensities during Transcranial Magnetic Stimulation (TMS) are described, particularly methods and system for modeling and displaying TMS using overlapping magnetic fields to stimulate deep brain regions.

Claims

1. A method of modeling Transcranial Magnetic Stimulation (TMS) on a deep brain target, the method comprising:

arranging representations of a plurality of TMS electromagnets around a model of a patient'"'"'s head, wherein each TMS electromagnet has a pre-computed magnetic field model;

calculating the intensity of the magnetic field at each of a plurality of brain regions by summing the magnetic field intensities of the portions of the pre-computed magnetic field model for each TMS electromagnet at each brain region; and

displaying the calculated magnetic field intensities for each of the plurality of brain regions.

2. The method of claim 1, further comprising pre-computing the magnetic field model for each of the TMS electromagnets.

3. The method of claim 1, wherein the step of calculating comprises calculating using the pre-computed magnetic field model for each TMS electromagnet wherein each pre-computed magnetic field model comprises an array of magnetic field intensity values indexed by position from the TMS electromagnet.

4. The method of claim 1, wherein the step of calculating comprises calculating using the pre-computed magnetic field model for each TMS electromagnet wherein the pre-computed magnetic fields have a resolution of less than about 1 mm.

5. The method of claim 1, further comprising registering the position of the representations of the TMS electromagnets relative to the model of the patient'"'"'s head with the position of actual TMS electromagnets relative to the patient'"'"'s head.

6. The method of claim 1, further comprising:

moving the representations of one or more of the TMS electromagnets relative to the model of a patient'"'"'s head;

re-calculating the intensity of the magnetic field for each of a plurality of brain regions; and

displaying the re-calculated magnetic field intensities for each of the plurality of brain regions.

7. The method of claim 1, wherein at least one of the plurality of brain regions comprises a non-cortical, deep brain region.

8. The method of claim 1, wherein the step of calculating the intensity of the magnetic field for each of a plurality of brain regions comprises linearly summing the overlapping magnetic field intensities for each brain region.

9. A method of generating a Transcranial Magnetic Stimulation (TMS) treatment plan for a patient, the method comprising the steps of:

displaying representations of a plurality of TMS electromagnets around a model of the patient'"'"'s brain;

calculating the intensity of the magnetic field for a plurality brain regions including a deep brain target based on the positions of the TMS electromagnets relative to the brain and based on pre-computed magnetic field models for each of the plurality of TMS electromagnets;

displaying the magnetic field intensity at the deep brain target on the model of the patient'"'"'s brain and on non-target regions in the patient'"'"'s brain; and

moving the representation of at least one TMS electrode and re-calculating the intensity of the magnetic field for the deep brain target until the magnetic field intensity at the deep brain target is above a stimulation threshold while the magnetic field intensity at non-target regions is below a stimulation threshold.

10. The method of claim 9, further comprising displaying a model of the patient'"'"'s brain and determining a deep brain target on the model of the patient'"'"'s brain.

11. The method of claim 9, further comprising pre-computing the magnetic field model for each of the TMS electromagnets.

12. The method of claim 9, further comprising registering the position of the representations of the TMS electromagnets relative to the model of the patient'"'"'s head with the position of actual TMS electromagnets relative to the patient'"'"'s head.

13. The method of claim 9, wherein the step of calculating the intensity of the magnetic field for each of a plurality of brain regions comprises linearly summing the overlapping magnetic field intensities for each brain region.

14. A system for modeling Transcranial Magnetic Stimulation (TMS) on a deep brain target, the system comprising:

a plurality of TMS electromagnets configured to be positionable at different locations and orientations around a patient'"'"'s head;

a registration sub-system configured to determine the positions and orientations of each of the plurality of TMS electromagnets and the patient'"'"'s head;

a magnetic field intensity modeling unit configured to calculate the intensity of the magnetic field for a plurality brain regions including a deep brain target and non-target regions based on the positions and orientations of the TMS electromagnets relative to the patient'"'"'s head and based on pre-computed magnetic field models for each of the plurality of TMS electromagnets; and

a display unit configured to display the magnetic field intensity determined by the magnetic field intensity modeling unit.

15. The system of claim 14, wherein the display unit is further configured to display the magnetic field intensity in three dimensions.

16. The system of claim 14, further comprising a controller configured to control the position and orientation of the TMS electromagnets.

17. The system of claim 14, wherein the magnetic field intensity modeling unit comprises treatment planning logic configured to determine if the magnetic field intensity of the deep brain target is greater than a threshold while the magnetic field intensity at non-target regions is below a stimulation threshold.