Nexstim Oy

Other

Koninklijke Philips Corporation N.v.

Varian Medical Systems International Ag

Elekta Neuromag Oy

Nexstim Oyj

Nexstim

Jarmo Ruohonen

Risto Ilmoniemi

Jari Karhu

Juha Virtanen

Raine Hurme

Perttu Sipilä

Gordon D DeMeester

Sami P Siljamaki

Ilkka Autio

Marko Ollikainen

C Michael Steckner

Robert K Carlson

Janne Kamppuri

Ikka Autio

Perttu SipilÄ

To overcome the difficulties inherent in conventional proton therapy systems, new techniques are described herein for synchronizing the application of proton radiation with the periodic movement of a target area. In an embodiment, a method is provided that combines multiple rescans of a spot scanning proton beam while monitoring the periodic motion of the target area, and aligning the applications of the proton beam with parameters of the periodic motion. For example, the direction(s) and frequency of the periodic motion may be monitored, and the timing, dose rate, and/or scanning direction and spot sequence of the beam can be adjusted to align with phases in the periodic motion.

Beam limiting device for intensity modulated proton therapy

The present publication discloses a device and method for generating magnetic pulses and directing them to brain. The device in accordance with the invention comprises means () for generating short, high energy current pulses (), means () for controlling amplitude () of the current pulses (), means () for generating high energy electromagnetic field stimulation pulses from the current pulses () and directing them to brain, and means () for measuring biologic responses to the stimulation pulses. In accordance with the invention the device includes means () for creating such a pulse sequence () of electromagnetic pulses where the amplitude () varies irregularly.

Magnetic stimulation device and method

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.

Method and system for displaying the electric field generated on the brain by transcranial magnetic stimulation

The present invention introduces a novel apparatus () for providing magnetic stimuli to the human brain, the apparatus () comprising a casing () and at least one coil winding () adapted to carry electrical current and enclosed within the casing () as well as cooling means () situated in thermal connection with the coil () and comprising a body made of electrically conductive and non-magnetic material so that the mutual inductance between the coil () and the cooling means () is essentially zero.

Magnetic stimulation coils with electrically conducting structures

An error in the co-registration of a coordinate system used to represent a head of a subject in image data with a coordinate system used to represent the location of trackers affixed to the scalp surface of the head and a tracked device, such as a transcranial magnetic stimulation ('TMS') induction coil device, is corrected using information representative of the actual distance between the tracked device and the scalp of the subject, such that representations of the tracked device and the subject's head are accurately shown on a display of a navigated brain stimulation ('NBS') system tracking movement of the tracked device in relation to the subject's head. The correction of the error in the co-registration is performed without collecting additional tracking information from trackers on a tracked TMS coil device and the head, which avoids interrupting NBS using the TMS coil device.

Method and apparatus for correcting an error in the co-registration of coordinate systems used to represent objects displayed during navigated brain stimulation

A method is disclosed in this publication for modeling different internal structures of a head, such as different parts of the brain, the method comprising the step of determining the location of the internal structures, such as the different cerebral parts, of at least one first head in a three-dimensional space by techniques such as magnetic resonance imaging or computer-aided tomography. According to the invention, the external dimensions of at least one second head are determined, and the location data of the internal structures of the first head are scaled in a three-dimensional space to correlate with the external dimensions of the second head, whereby the location data of the internal structures of the second head also become modeled without the need for anatomical images of the second head.

Method for three-dimensional modeling of the skull and internal structures thereof

The invention relates to a method for determining the effect of magnetic stimulation on human brain. According to the method, the stimulation dose is determined in different parts of the brain by summing cumulatively the electric field strength generated by the individual stimulus pulses. According to the invention, the position and alignment of a magnetic stimulation coil () is determined separately for each applied stimulus pulse in three dimensions relative to the head (), the number, repetition rate and intensity generated by the magnetic stimulation coil () are measured separately for each pulse, the coordinate data of the brain are determined substantially unambiguously in the same coordinate system with the magnetic stimulation coil () on the basis of information obtained from other kind of measurement, such as a tomographic scan or, e.g., a statistic database collected from a large number of patients, and the cumulative dose of electromagnetic radiation imposed on said desired point in the brain is determined on the basis of the location data available from the brain and the measurement data computed for the cumulative effect of the electromagnetic field evoked by said magnetic stimulation coil ().

Method and apparatus for dose computation of magnetic stimulation

An open MRI or other diagnostic imaging system (A) generates a three-dimensional diagnostic image representation, which is stored in an MRI image memory ( ). A laser scanner or other surface imaging system (B) generates a volumetric surface image representation that is stored in a surface image memory ( ). Typically, the volume and surface images are misaligned and the magnetic resonance image may have predictable distortions. An image correlating system (C) determines offset, scaling, rotational, and non-linear corrections to the magnetic resonance image representation, which are implemented by an image correction processor ( ). The corrected magnetic resonance image representation and the surface image representation are combined ( ) and stored in a superimposed image memory ( ). A video processor ( ) generates image representations from selected portions of the superimposed image representation for display on a human-readable monitor ( ).

External patient contouring

Disclosed is a method for producing a magnetic stimulation effect and/or a fake magnetic stimulation effect in a biological tissue. According to the method, the real magnetic stimulation is effected by virtue of inducing an electromagnetic field in said biological tissue with a sufficiently strong field strength to essentially excite said tissue, and the fake magnetic stimulation is effected by virtue of inducing an electromagnetic field in said biological tissue with a field strength that is weaker than the electromagnetic field required for an essential excitation of said tissue. According to the invention, said electromagnetic field weaker than the electromagnetic field strength required for an essential excitation of the tissue is produced by the steps of inducing at least one first electromagnetic field in said biological tissue and, simultaneously, inducing at least one second electromagnetic field superimposed with said first electromagnetic field but so deviated by its direction from the direction of said first electromagnetic that the sum effect of said electromagnetic fields in the target area of said biological tissue remains weaker than the electromagnetic field required for an essential excitation of said tissue. Also an apparatus is described suited for implementing the method.

Method for producing illusory magnetic stimulation

The present invention relates to a stimulator head of a magnetic stimulator used in the stimulation of living tissue such as the human brain. Such a stimulator bead comprises a stimulator head body ( ) suited for mounting the stimulator head on the magnetic stimulator equipment, at least one coil ( ) which is connected to said stimulator head body ( ) and is designed suitable for generating a stimulating magnetic field, and conductors ( ) for passing electric current from said magnetic stimulator into any of said at least one coil ( ). According to the invention, the stimulator head includes a housing ( ) which is connected to said stimulator head body ( ) and is designed to enclose at least one air-tight space ( ) which further separates each of said at least one stimulator coil ( ) from the other parts of said housing ( ) facing the object being stimulated. Further according to the invention, each of said at least one coil ( ) is placed in said housing ( ), whereby an acoustic insulation can be attained between each of said at least one coil ( ) and the object being stimulated by virtue of bringing the pressure in said air-tight space ( ) to a substantially low level.

Stimulator head and method for attenuating the sound emitted by a stimulator coil

The invention relates to a method and apparatus for examining and mapping the reactivity of and connections between different cortical areas. In the method an electromagnetic stimulus is induced in the interior parts of the head and the electromagnetic field generated around the skull is measured by electrical means (1). According to the method, the electromagnetic activity of the brain is measured using multichannel equipment, artefacts caused by the stimulus are eliminated from the signal containing the electromagnetic activity, a visualization of the activity changes in the measured signals is formed, and the areas of the head related to said activity generating said electromagnetic field are localized, or alternatively, the maximum of the sensitivity pattern of the multichannel activity measurement system is focused to a desired point.

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Vantaa, Finland

Jarmo Ruohonen