Firing patterns for deep brain transcranial magnetic stimulation

Abstract

Methods, devices and systems for Transcranial Magnetic Stimulation (TMS) are provided for synchronous, asynchronous, or independent triggering the firing multiple of electromagnets from either a single power source or multiple energy sources. These methods are particularly useful for stimulation of deep (e.g., sub-cortical) brain regions, or for stimulation of multiple brain regions, since controlled magnetic pulses reaching the deep target location may combine to form a patterned pulse train that activates the desired volume of target tissue. Furthermore, the methods, devices and systems described herein may be used to control the rate of firing of action potentials in one or more brain regions, such as slow or fast rate rTMS. For example, described herein are multiple electromagnetic stimulation sources, each of which are activated independently to create a cumulative effect at the intersections of the electromagnetic stimulation trajectories, typically by means of a computerized calculation.

What is claimed is: 
     
         1 . A Transcranial Magnetic Stimulation (TMS) method for stimulating neuronal tissue deep within a subject's brain by firing a plurality of electromagnets located at different locations around the subject's head, the method comprising:
 selecting deep brain target;   determining treatment objectives for the deep brain target and a plurality of collateral targets, wherein the collateral targets correspond to brain structures between the deep brain target and each of the electromagnets;   generating a treatment strategy configured to achieve the treatment objectives, wherein the treatment strategy comprises a stimulation pattern of firing of the electromagnets, and a set of individual control instructions for firing each of the electromagnets in the stimulation pattern; and   applying the treatment strategy to the plurality of electromagnets.   
     
     
         2 . The method of  claim 1 , wherein the step of determining treatment objectives for the deep brain target and the plurality of collateral targets includes referring to a database of suggested treatment objectives based on the target region. 
     
     
         3 . The method of  claim 1 , wherein the step of determining the treatment objectives includes setting the collateral treatment objectives to up-regulation, down-regulation or non-regulation. 
     
     
         4 . The method of  claim 1 , wherein the step of generating a treatment strategy comprises generating a plurality of candidate treatment strategies, simulating each candidate treatment strategy, scoring each simulated candidate strategy based on achievement of the treatment objectives, and selecting the treatment strategy from the scored candidate strategies. 
     
     
         5 . The method of  claim 1 , wherein the step of applying the treatment strategy comprises controlling each electromagnet to execute its individual control instructions. 
     
     
         6 . The method of  claim 1 , further comprising adjusting the position of the electromagnets to focus on the deep brain target. 
     
     
         7 . A Transcranial Magnetic Stimulation (TMS) system for stimulating neuronal tissue deep within a subject's brain, the system including:
 a plurality of electromagnets configured to be arranged around the subject's head;   a plurality of drivers, wherein each driver is configured to couple with one of the electromagnets to gate excitation of the electromagnet;   a stimulation controller configured to determine firing patterns for each of the electromagnets of the plurality of electromagnets so as to trigger stimulation at a target deep region of the subject's brain, wherein the firing patterns are determined by estimating the temporal and spatial summation of the effect of the firing of the plurality of electromagnets at the target deep tissue region.   
     
     
         8 . The system of  claim 7 , further comprising a distributor configured to communicate with the stimulation controller and each of the drivers of the plurality of drivers, wherein the distributor is further configured to command the drivers based on the control of the stimulation controller. 
     
     
         9 . The system of  claim 7 , further comprising a power source configured to supply power to the plurality of electromagnets. 
     
     
         10 . The system of  claim 7 , further comprising a plurality of power sources configured to supply power to the electromagnets. 
     
     
         11 . The system of  claim 7 , wherein the stimulation controller is configured to receive input indicating the location of the target deep tissue region relative to the plurality of electromagnets. 
     
     
         12 . A transcranial Magnetic Stimulation (TMS) system for stimulating neuronal tissue deep within a subject's brain, the system including:
 a plurality of electromagnets configured to be arranged around the subject's head;   a plurality of drivers, wherein each driver is configured to couple with one of the electromagnets to gate excitation of the electromagnet;   a distributor configured to couple with the drivers, wherein the distributor is further configured to command the drivers;   a stimulation controller configured to communicate with the distributors and to determine firing patterns for each of the electromagnets so as to trigger stimulation at a target deep region of the subject's brain, wherein the firing patterns are determined based on estimates of the temporal and spatial summation of the effect of the firing of the plurality of electromagnets at the target deep tissue region.