WO2009036040A1

WO2009036040A1 - Automated movement of electromagnets tracking eccentricity of the head

Info

Publication number: WO2009036040A1
Application number: PCT/US2008/075824
Authority: WO
Inventors: David Mishelevich; M. Bret Schneider
Original assignee: Neostim, Inc.
Priority date: 2007-09-10
Filing date: 2008-09-10
Publication date: 2009-03-19

Abstract

Methods and System for controlling the motion and position of one or more electromagnets during Transcranial Magnetic Stimulation (TMS) are described. In particular, described herein are systems and methods for rotating one or more electromagnet assemblies around a patient's head in an orbital path that follows the eccentricity of the head to maintain close proximity to the head.

Description

AUTOMATED MOVEMENT OF ELECTROMAGNETS TRACKING ECCENTRICITY

OF THE HEAD

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to the following application: U.S. Provisional

Patent Application Serial No. 60/971,211, filed on September 10, 2007, titled "AUTOMATED MOVEMENT OF ELECTROMAGNETS TRACKING ECCENTRICITY OF THE HEAD." This application is herein incorporated by reference in its entirety.

INCORPORATION BY REFERENCE

[0002] All publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

FIELD OF THE INVENTION [0003] The devices and methods described herein relate generally to moving and positioning electromagnets generating magnetic fields used for Transcranial Magnetic Stimulation.

BACKGROUND OF THE INVENTION

[0004] Transcranial Magnetic Stimulation (TMS) typically involves the application of electromagnetic fields to one or more target brain regions in order to excite or inhibit the target brain regions. For example, a single or double standard TMS coil placed on a patient's scalp and operated at a power level at, or slightly above, a patient's motor threshold will directly active neurons from the cortical crowns to the bottom of the cortical gyri- a depth of about l-3cm. Using this approach, deeper structures (herein referred to as "sub-cortical", even when these deeper areas are histologically layered in nature) are activated only secondarily through intracerebral neural connections. Conventional approaches typically do not reach greater depths (for example, the cingulate gyrus, the insula and other sub-cortical structures). Deep brain modulation cannot be accomplished by simply turning up the power of the stimulating electromagnet, because the intervening tissue, for example superficial cortex, will be over- stimulated, causing undesired side effects such as seizures.

[0005] Positive outcomes for treatment of depression refractory to drug treatment have been demonstrated with rTMS (repetitive Transcranial Magnetic Stimulation (A very et al., 2005). rTMS works indirectly because the superficial stimulation of the dorsolateral pre-frontal cortex is carried by nerve fibers to the deeper cingulate gyrus. More effective therapy of depression and treatment of a number of other conditions such as chronic pain, addiction, obesity, and obsessive compulsive disorder would be possible with focused brain stimulation at depth. U.S. Patent Application Serial No. 10/821,807 describes one variation of a device for providing deep brain stimulation with Transcranial Magnetic Stimulation.

[0006] In general, controlling the position of the TMS electromagnet relative to the subject's head (and therefore the target brain regions) is critical to any application of TMS, including deep brain modulation as described in U.S. Patent Application Serial No. 10/821,807. For example, Schneider and Mishelevich, in U.S. Patent Application 2005/0228209 describe the rotation of one or more electromagnets used in Transcranial Magnetic Stimulation of the brain around a subject's head to achieve TMS stimulation of deep structures. One embodiment described is the spinning of an electromagnet around the cranium on a movable gantry.

[0007] When moving or rotating TMS electromagnets about a subject's head, it may be particularly helpful to use a trajectory following the contour of the subject's head, rather than simply a circular, elliptical or other orbit. A circular orbit is inefficient from the energy delivery standpoint: magnetic field strength falls off rapidly as it leaves the face of a coil. In the case of transcranial magnetic stimulation, a circular orbit would mean that much energy delivered from the coil would never enter the brain of the user, as it would decay within the air spaces between the coil face and the sides of the head.

[0008] Although an electromagnet could be positioned closer or farther from a central target location in the brain by a robot arm moving closer or farther as required to avoid hitting the patient's head. However, currently described robotic arm systems (see, e.g., Fox et al. US 2003/0050527) are overly complex and expensive, and would require complicated control systems in order to maintain appropriate spacing between the electromagnet and the subject's head. Thus, it would be preferable to have the radial movement accomplished automatically using mechanical means, which may be more robust, reliable and lower-cost.

[0009] Described herein are method, devices and system that may address many of the issues described above. SUMMARY OF THE INVENTION

[00010] Described herein are devices, systems and methods for moving one or more electromagnets around a subject's head by having the electromagnets connected to a gantry and adjusting the distance between the patient's head and the electromagnet by adjusting the position of the electromagnets relative to the gantry. Thus, as an electromagnet is rotated around the subject's head, the electromagnet is moved outwards or inwards relative to the gantry to maintain a desired distance from the subject's head.

[00011] In general, the Transcranial Magnetic Stimulation (TMS) systems described herein include a gantry and a TMS actuator module that includes a TMS electromagnet and an actuator for moving the TMS electromagnet relative to the gantry. The actuator may be configured to move the TMS electromagnet in and/or out relative to the gantry (e.g., closer or farther from the patient's head), or it may be configured to move the TMS electromagnet around a track on the gantry; for non-round gantries, this will move the magnet closer and further from the subject's head. In this embodiment, the entire gantry may also be rotated around the subject's head so that the magnet may be positioned over the appropriate region of the head.

[00012] For example, described herein are TMS systems including: a gantry configured to at least partially encircle a patient's head; and a TMS actuator module connected to the gantry, wherein the TMS actuator module comprises a TMS electromagnet and an actuator for moving the TMS electromagnet in or out relative to the gantry. The TMS actuator module is further configured to move the TMS electromagnet to adjust the distance between the TMS electromagnet and the surface of the patient's head.

[00013] The gantry may be a frame or track. The gantry is generally configured to at least partially surround the patient's head, and may be configured so that the gantry can be positioned over the patient's head, or the patient's head may be placed into a fixed (or securable) gantry. The gantry may be circular, semi-circular, oval, semi-oval, or any other appropriate shape.

Although planar gantries are shown herein, other shapes, including gantries that allow the TMS actuator modules to be positioned at different heights as well as different radial positions relative the subject's head may be used. [00014] In general, the TMS actuator modules described herein may include one or more TMS electromagnets, and may be either movably connected to the gantry, or they may be fixed to the gantry. For example, the TMS actuator modules may be moved around the patient's head by riding on the gantry as a 'track'. In some variations, the entire gantry may be moved (e.g., rotated) around the patient's head. [00015] As mentioned, the TMS actuators described herein typically include a TMS electromagnet. Any appropriate TMS electromagnet (which may also be referred to as a "primary TMS electromagnet") may be used. For example, the TMS electromagnet may be a 70 mm double-coil electromagnet may be used, such as the 70 mm double-coil configuration from Magstim (Model 9925, Wales, UK). Other TMS electromagnets having different configurations may also be used. [00016] In some variations, the actuator included as part of the TMS actuator module is configured for moving the TMS electromagnet in and/or out relative to the gantry. This actuator may be a linear or uniaxial actuator that is configured to drive the TMS electromagnet position either forward or backward (e.g., in/out relative to the gantry to which the module is attached). Any appropriate actuator may be used, as described herein, including mechanical (e.g., threaded, geared, worm-screw, etc.), pneumatic, piezoelectric, etc. Solenoid-type actuators may also be used, and may be shielded or isolated from the TMS electromagnet to avoid interference with the TMS electromagnet field and operation.

[00017] In some variations, the distance between the TMS electromagnet and the subject is adjusted by moving both the TMS electromagnets around the gantry and by moving the gantry around the patient's head. For example, when a patient's head is positioned in the center of an oval gantry, moving the TMS electromagnet closer to the short axis of the oval will shorten the distance between the TMS electromagnet and the center of the oval; conversely, moving the TMS electromagnet closer to the long axis increases the distance to the center of the oval. Thus, moving the TMS electrode (which may be part of a TMS actuator module) around the gantry changes the radial position relative to the center of the gantry and therefore the patient, while moving the entire gantry may position the TMS electrode relative to the region of the patient's head. The combined motions of the gantry rotation and rotation of the TMS actuator module around the gantry, may be used to control the distance between the subject and the TMS electromagnet. In this embodiment, the TMS actuator module typically includes one or more TMS electromagnets and at least one gantry/magnet actuator configured to move the TMS electromagnet(s) around the gantry.

[00018] The systems described herein may also include one or more controllers configured to determine the position of the TMS actuator module and to instruct the actuator of the TMS actuator module to adjust position of the TMS electromagnet relative to a patient's head. A controller may be part of an overall system controller (or sub-system controller), and may execute control logic to determine the position and/or position adjustments to apply. Controllers may include hardware, software, firmware, or any other appropriate structures necessary to perform the function described herein. Controllers may be analog or digital, and may receive input (including feedback/feedforward input) from one or more detectors and/or sensors, particularly position detectors. [00019] The system may include any appropriate detector, including a position detector.

For example, a position detector may be configured to determine the position of the TMS actuator module on the gantry. Gantry/actuator position detectors may be particularly useful in variations in which the module moves along the gantry. In some variations, the position of the module on the gantry may be used to indicate how the TMS actuator should be controlled. For example, the controller may include pre-set or pre-determined instructions for positioning the TMS electromagnet relative to the gantry at certain gantry positions. Thus, the instructions may be based on a general head shape relative to the gantry shape, or they may be determined by mapping the gantry position relative to a subject's head after positioning the gantry relative to the subject's head (positioning the gantry relative to the subject's head may mean either placing the gantry near the subject's head, or placing the subject's head in/near the gantry). In some variations, the gantry includes markings, marks or other indicators that indicate where a module is on the gantry; a detector may sense these indicators to determine position. [00020] One or more position detectors for detecting the orientation of the gantry relative to the patient (gantry/patient detectors) may also be used. These detectors may be particularly helpful in variations in which the entire gantry is rotated.

[00021] In some variations, the detector is a position detector configured to determine the position of the TMS electromagnet relative to a patient's head. These detectors (e.g., "patient/electromagnet detectors") may also be referred to as head-magnet detectors. A head position detector may include any appropriate sensor, such as an optical sensor, etc.

[00022] In some variations, the system includes a plurality of TMS actuator modules, wherein each TMS actuator module comprises a TMS electromagnet and an actuator for moving the TMS electromagnet in or out relative to the gantry. Any appropriate number of modules may be included, and a single controller may be used to control all or a subset of the modules, or multiple controllers may be used.

[00023] In variations in which the TMS actuator module is configured to move along the gantry, the module may include one or more a gantry/magnet actuators configured to move the TMS actuator module along the gantry. In some variations the gantry includes a track that is geared, and the gantry/magnet actuator may move by engaging the gears. [00024] In some variations, the system includes one or more tilt actuators as part of the

TMS actuator module. A tilt actuator is typically configured to adjust the angle of the TMS electromagnet relative to a patient's head. Tilt actuators may allow slight rotation (which may be limited) in one or two axis (e.g., the axes in the plane or face of the TMS facing the subject's head) so that the angle of the TMS magnet's emitted field relative to the patient's head can be controlled. Tilt actuators may be mechanical, piezo, or any other appropriate actuator. The controller may also be configured to control the tilt actuator(s).

[00025] Also described herein are TMS system comprising: a gantry; a TMS actuator module on the gantry, wherein the TMS actuator module comprises a TMS electromagnet, and a uniaxial actuator for moving the TMS electromagnet in or out relative to the gantry; at least one position detector configured to determine the position of the TMS electromagnet relative to a patient's head; and a controller configured to determine the position of the TMS electromagnet relative to the patient's head based on input from the position detector, and to instruct the TMS actuator module to adjust the distance between the TMS electromagnet and the surface of the patient' s head based on the determined position.

[00026] As mentioned above, the TMS actuator module may be configured to move along the gantry and comprise a gantry/magnet actuator configured to move the TMS actuator module along the gantry. Alternatively, the TMS actuator module may be secured to the gantry. [00027] Methods for TMS stimulation, including methods of positioning a TMS electromagnet relative to a subject' head are also described. In general, these methods include the steps of moving a TMS actuator module around the subject's head and actuating the TMS actuator to move the TMS electromagnet along one axis (e.g., in/out) to move it closer or further from the subject's head, based on the position of the module relative to the subject's head. [00028] For example, described herein are TMS methods comprising: moving a TMS actuator module along a gantry, wherein the TMS actuator module comprises a TMS electromagnet and an actuator configured to move the TMS electromagnet towards or away from a patient's head relative to the gantry; and adjusting the distance between the TMS electromagnet and the patient's head using the actuator. [00029] In any of the systems and methods described herein, the distance between the subject's head and the TMS electromagnet may be kept at a constant distance. For example, the step of adjusting the distance between the TMS electromagnet and the patient's head may comprise maintaining a relatively constant distance between the TMS electromagnet and the patient's head as the TMS actuator module is moved along the gantry. [00030] The methods may also include the step of activating the TMS electromagnet to apply electromagnetic field to neuronal target. In some variations, the targets may be deep brain targets; in some variations, the targets are cortical or superficial targets. [00031] The method may also include the step of determining the position of the TMS electromagnet relative to the patient's head. For example, the method may include the step of sensing distance between TMS electromagnet and the subject's head. In some variations, the step of adjusting the distance between the TMS electromagnet and the patient's head includes determining the distance between the TMS electromagnet and the subject's head and controlling the actuator to adjust the distance of the TMS electromagnet based on this distance. [00032] Also described herein are Transcranial Magnetic Stimulation (TMS) methods including the steps of: positioning a gantry relative to a subject's head; moving a TMS actuator module along a gantry, wherein the TMS actuator module comprises a TMS electromagnet and an actuator configured to move the TMS electromagnet towards or away from a patient's head relative to the gantry; determining the position of the TMS electromagnet relative to the patient's head; adjusting the distance between the TMS electromagnet and the patient's head using the actuator; and activating the TMS electromagnet to apply an electric field to a neuronal target. As mentioned, the step of adjusting the distance between the TMS electromagnet and the patient's head comprises maintaining a relatively constant distance between the TMS electromagnet and the patient's head as the TMS actuator module is moved along the gantry. In some variations, the system includes feedback from the sensors that is configured to respond sufficiently quickly so the patient will not be struck by the device. [00033] In addition to systems and methods for moving a TMS electromagnet around a subject's head, the principles described herein for moving around a subject's head may also be used for moving other devices (including energy sources and/or sensors) around a subject's head. For example, described herein are transcranial tracking systems comprising: a gantry configured to at least partially encircle a patient's head; and an actuator module connected to the gantry, wherein the actuator module comprises an energy source and an actuator for moving the energy source in or out relative to the gantry; wherein the actuator module is further configured to move the energy source to adjust the distance between the energy source and the surface of the patient's head. The energy source may be selected from the group consisting of: light, radio frequency, acoustic, and, thermal energy sources, or any other appropriate energy source. [00034] Also described herein are transcranial tracking system, the system comprising: a gantry configured to at least partially encircle a patient's head; and an actuator module connected to the gantry, wherein the actuator module comprises a sensor and an actuator for moving the sensor in or out relative to the gantry; wherein the actuator module is further configured to move the sensor to adjust the distance between the energy source and the surface of the patient's head. [00035] Also described herein are TMS systems and methods including a gantry configured as a track along which one or more TMS electromagnets may move or be positioned. In such variations, the gantry may be shapeable or configurable to a patient's head shape. For example, the gantry may be customizable to fit the contours of a patient's head. Thus, the gantry may be flexible and/or shapeable or may include links or hinge regions allowing its shape around the subject's head to be spaced an appropriate distance (e.g., a tϊxed distance) from the subject's head.

[00036] In operation, such a customizable gantry may be pre-fϊt to a specific patient prior to TMS or other operation. For example, in some methods, the gantry may be made flexible or movable, and adjusted to be spaced around a subject's head. After (or during) this fitting step, the gantry may be locked into position. For example, the gantry may includes a track made of lockable links (e.g., each 1 mm or less), that can be configured to the head profile, then tensioned or otherwise locked into position. TMS treatment may then be performed using the shaped track. The shape of the gantry may provided to a controller for the TMS system. For example, the relative position along the gantry corresponding to various patient head anatomy may be correlated prior to treatment and provided to the controller, which can use this information to control the application of TMS. During treatment with the customized gantry, it is not necessary to move the TMS electromagnet in/out relative to the gantry, as described for other variations. Thus, these variations may not require an additional TMS actuator module, although in some variations it may be beneficial to include such a module, or a module modified to include tilt actuators and or an actuator for moving the TMS electrode around the subject's head.

BRIEF DESCRIPTION OF THE DRAWINGS

[00037] FIG.1 shows one variation of a TMS actuator module.

[00038] FIG. 2 illustrates one variation of a TMS method including a method for adjusting the position of a TMS electromagnet at different positions relative to a patient's head using a circular gantry.

[00039] FIG. 3 illustrates a gantry with multiple electromagnets attached to plates that run on a track around the gantry in end-to-end fashion.

[00040] FIG. 4 illustrates another variation of an oval gantry having two electromagnets. [00041] FIG. 5 schematically illustrates a TMS system as described herein.

[00042] FIG. 6 illustrates one TMS method as described herein.

[00043] FIG. 7 illustrates a customizable TMS gantry.

DETAILED DESCRIPTION OF THE INVENTION

[00044] In general, the systems and devices described herein include a gantry configured to at least partially surround a patient's head, and one or more TMS actuator modules configured to attach to the gantry; the TMS actuator modules include a TMS electromagnet and an actuator that is configured to move the TMS electromagnet towards or away from the subject's head relative to the gantry. [00045] FIG. 5 schematically illustrates one variation of a TMS system and shows the relationship of some of these elements. In this example, a plurality of TMS actuator modules 503, 503' are positioned on the gantry 501. The gantry may be a frame or track to which the TMS actuator modules are connected. In some variations the TMS actuator modules 503, 503' are moveably secured to the gantry 501. Thus, the modules 503, 503' may be moved around the gantry 501. In this variation, the modules may be rotated or moved around the subject's head by moving around the gantry 501. In this variation, the TMS actuator modules may also include a gantry/magnet actuator configured to move the TMS actuator module along the gantry (not shown in FIG. 5). In some variations, the gantry itself may be moved around the subject's head; the modules 503, 503' may be secured in a fixed position on the gantry, or may be movable as well. An actuator for moving the entire gantry around the subject's head may be referred to as a gantry rotator actuator.

[00046] The gantry may be any appropriate shape to fit at least partially around the subject's head, and may be secured to an adjustable mount (e.g., arm or other positioned). Alternatively, the gantry may be rigidly fixed to the system, and the patient may be positioned within it.

[00047] In general, the system is configured so that as the modules are moved around the patient's head, the distance between the TMS actuator modules (particularly the TMS electromagnet 505, 505' of the TMS actuator module) and the patient's head is maintained at a desired separation. For example the distance may be constant, or may be varied or based on a predetermined value given patient anatomy, or based on the target (e.g., the TMS electromagnet may be brought closer when the target is deeper). In the system described herein, the adjustment of the distance between the TMS electromagnet and the patient's head is achieved by the actuator 507, 507'. [00048] The actuator 507, 507' may be a uniaxial or in/out actuator for moving the TMS electromagnet in/out relative to the gantry or a gantry/magnet actuator for moving the TMS electromagnet around the gantry. In variations in which the actuator is configured to move the electromagnet in and/or out relative to the gantry, the actuator will move the TMS electromagnet closer or further from the patient's head based on either (or both) the position of the TMS actuator module on the gantry or the distance between the TMS electromagnet of the module and the subject's head.

[00049] In some variations the TMS actuator module(s) 503, 503' also includes one or more tilt actuators (not shown) which may also be used to adjust the position of the TMS electromagnet relative to the subject's head. For example, a tilt actuator may be used to aim the TMS electromagnet to a neuronal target as (or after) movement. In some variations the tilt actuator is a limited actuator that may angle the electromagnet slightly (e.g., between -45 and -45 degrees, between 30 and +30 degrees, etc.) in one or two axes. The tilt actuator may be any appropriate actuator configured to tilt the TMS electromagnet as desired. A tilt actuator may be connected to the same controller used to control the primary actuator of the TMS actuator module.

[00050] As indicated in FIG. 5, a controller 511 may also be used as part of the system, and may help control the actuator 507, 507' of the TMS actuator module 503, 503' to position the TMS electromagnet 505, 505'. The controller may include control logic, and may calculate the distance that the TMS electrode needs to be adjusted by the actuator 507, 507', and may send instructions to the actuator 507, 507'. The controller may receive input from one or more position detectors 513 (or position sensors). For example, a head-magnet detectors 517 may be included that indicates the distance between the TMS electromagnet and the subject's head. In some variations a gantry position detector 515 be used, which may detect the position of the TMS actuator module on the gantry (in variations which include TMS actuator modules that move relative to the gantry).

[00051] FIG. 1 illustrates one variation of a TMS actuator module. In this variation, the module comprises a TMS electromagnet 100 and an actuator mechanism 102. An actuator module moves its associated electromagnet radially in and out (e.g., along one axis). Electromagnet 100 is moved in and out as threaded rod 102 (shown divided into two sections in the drawing) moves in and out of collars 115 and 120, when driven by linear stepper motor 140. The apparatus is stabilized on sliding rods 110 and 112 that slide through frame elements 105 and 125. In another variation, the actuator module uses a similar approach, and incorporates a helically cross-threaded rod that reverses direction automatically at each end of the path, so the motor only needs to rotate in one direction. An example of this helically cross-threaded rod approached in used in some types of fishing reels that have a device that moves back and forth over the spool of the reel to lay down the line in an orderly fashion, first in one direction and then in the other to avoid entanglement of said fishing line. In other variations, the actuator may be a pneumatic actuator, a piezoelectric actuator, a solenoid, etc. [00052] In any of these actuator variations, components of the actuator module are preferably made from non-ferromagnetic materials, particularly the regions nearest the TMS electromagnet. Further, the actuator may be configured so that it does not interfere with the field emitted by the TMS electromagnet.

[00053] As mentioned, the extension of the electromagnet from the gantry (e.g., toward or away from the subject's head) may depend on the position of the electromagnet in the orbit. When the position of the gantry where the actuator module is located is far from the patient's head, the electromagnet may be moved in. Conversely, if the position of the gantry where the module is located is close to the patient's head, the electromagnet may be moved out. If multiple electromagnets are simultaneously involved, each may have its own actuator module. [00054] An actuator module, such as the one illustrated in FIG. 1, can be placed in a gantry so that it may ride around a track (e.g., formed from the internal lateral edge or the top edge of the gantry). In another embodiment, the actuator module can be attached to the arm of a robot that is rotating around the head of a patient in a circular or other orbit. [00055] The speed of the actuator in translating the TMS electromagnet (e.g., toward and away from stepper motor 140) may be increased by including lever arms that translate movements by a plate at the end of the threaded rod into larger movements by the coil, hi addition, the actuator may include one or more gears for controlling the motion of the TMS electrode.

[00056] As mentioned above, in some variations, the movement of the actuator (e.g., stepper motor 140) may be determined in part by the position on the gantry. For example, the actuator of the TMS actuator module may be directed by switches that are tripped in anticipation of the module's coils (TMS electromagnet) arriving at a given location with respect to a patient's head. Alternatively, a controller, or device exercising control logic, e.g., a computer running control logic, may direct movements of the actuator (stepper motor 140). [00057] FIG. 2 shows one variation of a circular-gantry embodiment, hi this example, the head of the patient (which may be a human or animal subject) 200 is surrounded by circular gantry 210. The circular gantry is at some positions closer to the head and sometimes further away. When the position of the TMS electromagnet 220 is close to the gantry, the associated TMS actuator module 222 is drawn back. In FIG. 2, for the same of simplicity, the TMS actuator modules are shown removed from the gantry, although the position of the actuator is indicated. Moving clockwise in the diagram, as the actuator module 237 (including TMS electromagnet 220, 230, 240) circumferentially moves to where what was electromagnet 220 is now electromagnet 230, the TMS actuator module moves the electromagnet so it is in position 235, closer to the head even though the circular gantry is further from the head than it was when the electromagnet was at position 220. Moving clockwise again, as the actuator module 247 moves to where what was electromagnet is at position 240, the TMS actuator module moves the electromagnet so it is now in position 245, closer to the head even though the circular gantry is further from the head than it was when the electromagnet was at position 235. Thus, the radial distance of the electromagnet to the head is maintained relatively constant in this example. [00058] Such an embodiment will also apply in cases where the gantry is not circular, but oval (particularly where the shape of the oval of the gantry is not the shape of the oval of the head) or otherwise shaped.

[00059] FIG. 3 illustrates a variation having an oval gantry that has one or more electromagnets attached to plates with the plate ends running on a track on the gantry. In FIG. 3, electromagnet(s) 330 connected to plates 340 that are configured to run around a gantry 310 surrounding head 300. The plates may be connected end to end at points 350, and the ends of the plates that are attached to the gantry run around the oval gantry, thus allowing radial positioning close or far from the target as appropriate. In one variation, the gantry may also be rotated relative to the center of the patient's head. This may allow the position of a particular electromagnet to be adjusted by rotating both the electromagnet(s) around the gantry, and the gantry around the head. The combined motions of the two may control the separation between the patient's head and the TMS electromagnet. In this variation, the actuator is configured as a gantry actuator, which moves the TMS electromagnet (e.g., attached to plate 340) around the oval-shaped track, and an additional actuator (not shown) that moves the gantry around the patient's head.

[00060] In FIG. 3, there are two types of actuators that may be responsible for adjusting the separation between the TMS electromagnet and the patient's head. First, the TMS actuator module includes an actuator that moves the TMS electrode 330 (attached to plate 340) around the oval gantry track. This is a magnet/gantry actuator. Second, the entire gantry (including the track) may be rotated around the subject's head. This second actuator is a gantry rotator actuator. A controller may coordinate the motions of the two actuators. In this example, the TMS actuator module may be thought of as including a single magnet/gantry actuator that moves all of the connected magnets and plates around the oval gantry track. [00061] Another oval-gantry embodiment is shown in FIG. 4. In FIG. 4, the oval gantry

410 surrounds head 400. Electromagnet(s) 420 are attached to plates 430 that are attached at end points 440 to a track running on the gantry. The track (not shown) is located on the internal lateral surface of the gantry or on the top of the gantry. Again, by combining the motion of the electromagnets 420 around the oval gantry and the moving the gantry 410 around the patient's head, the distance between the electromagnets and the patient's head may be controlled.

[00062] FIG. 6 illustrates one variation of a method of adjusting the distance between a patient and one or more TMS electrodes. In FIG. 6, the first step is to position a gantry relative to the subject's head 601. Next, the TMS actuator module (which includes a TMS electrode and actuator) is moved around the subject's head 603. For example, in the variations shown in FIGS. 1 and 2, in which the modules may move around the gantry or be fixed to the gantry, and include an actuator configured to move the TMS electromagnet in/our relative to the gantry, the module may be moved by a gantry actuator or by moving the entire gantry (with attached module). Similarly, in the variations shown in FIGS. 3 and 4, the TMS actuator module includes a gantry actuator that moves the TMS electrode(s) around the gantry track to a new position. Next, the actuator of the TMS actuator module is driven to adjust the distance between the TMS electromagnet and the subject's head 605. This step may be done concurrently with the step of moving the TMS electrode 603, or it may be done before or after this step. Feedback (e.g., input from one or more detectors) may also be used to help control the movement of the actuator(s). For example, an actuator may extend the TMS electromagnet in/out relative to the gantry. In some variations, an actuator rotates the gantry around the subject's head, changing the separation between the TMS electromagnet and the subject's head. Finally, the TMS electromagnet may be activated 607 to stimulate a region of the subject's brain by TMS. These steps may be repeated 611. [00063] Moving one or more devices in a pathway around a subject's head mirroring the head contours may have uses outside of TMS, as well. For example, devices such as recording electrodes for picking up electronic signals from the brain, sensing coils for detecting magnetic signals emanating from the brain, RF antennae detection radio-frequency signals, or transmitting antenna arrays for stimulating the brain, may all be rotated around a subject's head, and may benefit from the methods and systems described herein. Thus, it is to be understood that these devices and systems may be readily adapted for these uses (e.g., by replacing the TMS electromagnet with one or more of these devices, or other such devices). [00064] FIG. 7 illustrates another variation of a TMS system including a customizable gantry. In FIG. 7, the gantry initially as a shape 701 that is separated by the patient's head 705 and does not include a uniform distance between the gantry and the head (or a desired distance). The gantry 701 may be 'customized' by placing it a desired distance x from the patients head, as shown by the arrows in FIG.7, so that it has the configuration shown 703. In this example, the gantry may be formed of links or elements that may be bent (e.g., hinged, bendable, etc.) so that they can confirm to the head at a separation distance desired (e.g., a constant distance x). In this example, a single TMS module 707, 709 is movably attached to the gantry, as shown. As described for FIGS. 3 and 4, above, the TMS electromagnet may be part of a module (e.g., a base or plate) that is movably attached to the gantry, and may be repositioned by a controller. The gantry may include indicators indicating position, which may be detected, and this information provided to the controller which may use it to control the motion along the gantry. [00065] The various embodiments described above are provided by way of illustration only and should not be construed to limit the invention. Based on the above discussion and illustrations, those skilled in the art will readily recognize that various modifications and changes may be made to the present invention without strictly following the exemplary embodiments and applications illustrated and described herein. Such modifications and changes do not depart from the true spirit and scope of the present invention, which is set forth in the following claims.

REFERENCES

Avery, D.H., Holtzheimer III, P.E., Fawaz, W., Russo, Joan, Neumaier, J. and Dunner, D.L., Haynor, D.R., Claypoole, K.H., Wajdik, C. and P. Roy-Byrne, "A Controlled Study of Repetitive Transcranial Magnetic Stimulation in Medication-Resistant Major Depression," Biological Psychiatry, 2005, 59: 187-194.

Schneider, M.B. and DJ. Mishelevich, U.S. Patent Application No. 10/821,807 "Robotic apparatus for targeting and producing deep, focused transcranial magnetic stimulation"

Claims

CLAIMSWhat is claimed is:

1. A Transcranial Magnetic Stimulation (TMS) system comprising: a gantry configured to at least partially encircle a patient's head; and a TMS actuator module connected to the gantry, wherein the TMS actuator module comprises a TMS electromagnet and an actuator for moving the TMS electromagnet in or out relative to the gantry; wherein the TMS actuator module is further configured to move the TMS electromagnet to adjust the distance between the TMS electromagnet and the surface of the patient's head.

2. The system of claim 1 , further comprising a controller configured to determine the position of the TMS actuator module and to instruct the actuator of the TMS actuator module to adjust position of the TMS electromagnet relative to a patient's head.

3. The system of claim 1 , wherein the actuator comprises a uniaxial actuator.

4. The system of claim 1 , further comprising a plurality of TMS actuator modules, wherein each TMS actuator module comprises a TMS electromagnet and an actuator for moving the TMS electromagnet in or out relative to the gantry.

5. The system of claim 1, wherein the TMS actuator module is configured to move along the gantry and comprises a gantry/magnet actuator configured to move the TMS actuator module along the gantry.

6. The system of claim 1, wherein the TMS actuator module is secured in position on the gantry.

7. The system of claim 1 , further comprising a position detector configured to determine the position of the TMS actuator module on the gantry.

8. The system of claim 1, further comprising a position detector configured to determine the position of the TMS electromagnet relative to a patient's head.

9. The system of claim 1 , wherein the TMS actuator module comprises a tilt actuator configured to adjust the angle of the TMS electromagnet relative to a patient's head.

10. The system of claim 1, wherein the gantry comprises position indicators.

11. The system of claim 1, wherein the gantry is selected from the group consisting of: a circular gantry, an oval gantry, a semi-circular gantry.

12. A Transcranial Magnetic Stimulation (TMS) system comprising: a gantry; a gantry rotator actuator configured to rotate the gantry around a subject's head; a TMS actuator module on the gantry, wherein the TMS actuator module comprises a TMS electromagnet, and a gantry/magnet actuator configured to move the TMS electromagnet along the gantry; and a controller configured to determine the position of the TMS electromagnet relative to the patient's head and to coordinate the motion of the gantry rotator actuator and the actuator of the TMS actuator module to adjust the distance between the TMS electromagnet and the surface of the patient's head.

13. The system of claim 12, wherein the gantry is elliptical.

14. A Transcranial Magnetic Stimulation (TMS) method, the method comprising: moving a TMS actuator module along a gantry, wherein the TMS actuator module comprises a TMS electromagnet and an actuator configured to adjust the position of the TMS electromagnet relative to the gantry; and adjusting the distance between the TMS electromagnet and the patient's head using the actuator.

15. The method of claim 14, wherein the step of adjusting the distance between the TMS electromagnet and the patient's head comprises maintaining a relatively constant distance between the TMS electromagnet and the patient's head as the TMS actuator module is moved along the gantry.

16. The method of claim 14, further comprising rotating the gantry around the subject's head.

17. The method of claim 14, further comprising determining the position of the TMS electromagnet relative to the patient's head.

18. The method of claim 14, wherein the step of adjusting the distance between the TMS electromagnet and the patient's head comprises determining the distance between the TMS electromagnet and the subject's head and controlling the actuator to adjust the distance of the TMS electromagnet based on this distance.

19. A Transcranial Magnetic Stimulation (TMS) method, the method comprising: positioning a gantry relative to a subject's head; moving a TMS actuator module along a gantry, wherein the TMS actuator module comprises a TMS electromagnet and an actuator configured to move the TMS electromagnet towards or away from a patient's head relative to the gantry; determining the position of the TMS electromagnet relative to the patient's head; adjusting the distance between the TMS electromagnet and the patient's head using the actuator; and activating the TMS electromagnet to apply an electric field to a neuronal target.

20. The method of claim 19, wherein the step of adjusting the distance between the TMS electromagnet and the patient's head comprises maintaining a relatively constant distance between the TMS electromagnet and the patient's head as the TMS actuator module is moved along the gantry.

21. A transcranial tracking system, the system comprising: a gantry configured to at least partially encircle a patient's head; and an actuator module connected to the gantry, wherein the actuator module comprises an energy source and an actuator for moving the energy source in or out relative to the gantry; wherein the actuator module is further configured to move the energy source to adjust the distance between the energy source and the surface of the patient's head.

22. The system of claim 21, wherein the energy source is selected from the group consisting of: light, radio frequency, acoustic, and, thermal energy sources.

23. A transcranial tracking system, the system comprising: a gantry configured to at least partially encircle a patient's head; and an actuator module connected to the gantry, wherein the actuator module comprises a sensor and an actuator for moving the sensor in or out relative to the gantry; wherein the actuator module is further configured to move the sensor to adjust the distance between the energy source and the surface of the patient's head.