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Ruohonen J.,Nexstim
Neurophysiologie clinique = Clinical neurophysiology | Year: 2010

Transcranial magnetic stimulation (TMS) is a unique method for non-invasive brain imaging. The fundamental difference between TMS and other available non-invasive brain imaging techniques is that when a physiological response is evoked by stimulation of a cortical area, that specific cortical area is causally related to the response. With other imaging methods, it is only possible to detect and map a brain area that participates in a given task or reaction. TMS has been shown to be clinically accurate and effective in mapping cortical motor areas and applicable to the functional assessment of motor tracts following stroke, for example. Many hundreds of studies have been published indicating that repetitive TMS (rTMS) may also have multiple therapeutic applications. Techniques and protocols for individually targeting and dosing rTMS urgently need to be developed in order to ascertain the accuracy, repeatability and reproducibility required of TMS in clinical applications. We review the basic concepts behind navigated TMS and evaluate the currently accepted physical and physiological factors contributing to the accuracy and reproducibility of navigated TMS. The advantages of navigated TMS over functional MRI in motor cortex mapping are briefly discussed. Illustrative cases utilizing navigated TMS are shown in presurgical mapping of the motor cortex, in therapy for depression, and in the follow-up of recovery from stroke.


A visualization surface representative of a portion of the brain at a depth below the head surface of the subject is generated by combining an actual representation of the head surface with an idealized representation of the head surface. The combining is a function of the depth and is performed to minimize in the visualization surface any irregularities existing in the actual head surface of the subject. A display shows the visualization surface overlaid on a volumetric image of the brain, the electric field induced on a region of the visualization surface by a transcranial magnetic stimulation (TMS) induction coil device positioned above the head surface and the TMS coil device. By viewing the display, a user of the TMS coil device can interactively position the TMS coil device in relation to the head surface and, for a target site on the brain at a selected depth, determine the position at which the TMS coil device induces a maximum E-field on a visualization surface corresponding to the selected depth.


Described herein are methods including determining a structural effectiveness index (SEI) for a target area of a brain which accounts for the effectiveness of a Transcranial Magnetic Stimulation (TMS) pulse based on at least one neurological feature of the brain. An SEI may include an anisotropy index (AI). An AI may account for the effectiveness of a TMS pulse based at least on the local anisotropy of the target area. An SEI may include a connectivity index (CI). A CI may account for the effectiveness of a TMS pulse at a different location of the brain than a stimulated target area. Moreover, the CI can be based at least partially on white matter tract connections. The SEI of at least one area of a brain may be used in order to plan a minimum effective dose at that location based on the actual neurological structure there, e.g. the anisotropy or white matter tracts at that area.


Patent
Nexstim | Date: 2014-06-03

Provided herein is a multichannel Transcranial Magnetic Stimulation (mTMS) coil device with two or more overlapping coil windings within a casing. The mTMS coil device is capable of adjusting parameters of the stimulation of magnetic and induced electric fields through the selective control of the multiple coil windings within the mTMS coil device. Additionally, provided are methods of operation including navigated TMS for adjusting parameters such as location, direction and/or orientation of magnetic and induced electric fields from mTMS coil devices.


A method of and system for monitoring a patients EEG (electroencephalogram) during TMS (Transcranial Magnetic Stimulation) are disclosed. The system comprises a TMS device to generate, when in an active state, a plurality of magnetic pulses, which can be applied either as a burst, comprising a plurality of pulses grouped together, or as individual pulses, to the patients head, in accordance with a TMS treatment protocol. An EEG system is provided to measure EEG data resulting from the TMS treatment protocol being applied to the patient. The system further comprises control means in communication with the TMD device and the EEG system, the control means being arranged to activate the EEG system during the time periods when the TMS device is not generating pulses, such that the EEG data measurement is continuously applied or interleaved with the magnetic pulses being generated in accordance with the TMS treatment protocol, so as to monitor treatment efficacy and detect potential seizures.


Patent
Nexstim | Date: 2013-11-29

According to an example embodiment of the present invention, there is provided an apparatus, comprising a first arm configured to accept a device, the first aim comprising a first counterweight arrangement, a second arm supporting the first arm by a coupling, and a base defining a curve and having the second arm mounted thereon, wherein the second arm is movable along the curve, the base configured to be mounted on a chair. The second arm may be furnished with a second counterweight arrangement.


Patent
Nexstim | Date: 2016-01-06

According to an example embodiment of the present invention, there is provided an apparatus comprising at least one receiver configured to receive signals relating to a position of a device relative to a head, at least one processing core configured to determine, at least in part based on the received signals, the position of the device relative to the head, to compare the position of the device relative to the head to information concerning a position corresponding to a maximal induced electric field, and to cause signals to be transmitted, and wherein the transmitted signals are configured to cause a display to indicate a deviation of the position of the device from the position corresponding to the maximal induced electric field


Patent
Nexstim | Date: 2015-06-16

According to an example embodiment of the present invention, there is provided an apparatus comprising at least one receiver configured to receive signals relating to a position of a device relative to a head, at least one processing core configured to determine, at least in part based on the received signals, the position of the device relative to the head, to compare the position of the device relative to the head to information concerning a position corresponding to a maximal induced electric field, and to cause signals to be transmitted, and wherein the transmitted signals are configured to cause a display to indicate a deviation of the position of the device from the position corresponding to the maximal induced electric field


Patent
Nexstim | Date: 2015-06-03

According to an example embodiment of the present invention, there is provided an apparatus, comprising a first arm configured to accept a device, the first arm comprising a first counterweight arrangement, a second arm supporting the first arm by a coupling, and a base defining a curve and having the second arm mounted thereon, wherein the second arm is movable along the curve, the base configured to be mounted on a chair. The second arm may be furnished with a second counterweight arrangement.


A transcranial magnetic stimulation induction coil device having a tracking device with a mating portion and at least one set of two or more reflective elements, a casing separate from a tracking device and containing at least one coil winding having a known orientation within the casing, and an attachment portion corresponding to the mating portion for removably attaching the tracking device to the casing such that, when attached, the reflective elements have a known orientation with respect to the known orientation of the coil winding.

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