Siemens Aktiengesellschaft

Bsh Bosch Und Siemens Hausgeraete Gmbh

Guenter Ries

Rudolf Roeckelein

Rainer Alfred Kuth

Klaus Abraham-Fuchs

Johannes Reinschke

Friedrich Fuchs

Ralph Oppelt

Ralph Kimmlingen

Horst Siebold

Mario Bechtold

Roland Schmidt

Marion Meusel

Dieter Schmettow

Heinz-Werner Neumueller

A device is for repeated semi-invasive abrasion of lesions on the walls of hollow organs, in particular blood vessels or the gastrointestinal tract of a patient. The device includes an outer stent which, fixed in position at the site of the lesions, can be clamped against the wall of the hollow organ and has recesses through which the lesions can inwardly protrude. The device further includes a cutting body which is guided within the outer stent and only negligibly narrows the internal bore of the outer stent, which cutting body has cutting edges sliding on the inner side of the outer stent and is coupled magnetically to an external magnet system via which it can turn about the stent axis and/or can move longitudinally along the stent axis.

Device for repeated semi-invasive abrasion of lesions on the walls of hollow organs

A device is for introducing a stent into a hollow organ, in particular into the gastrointestinal tract of the body of a patient. The device includes a magnet system which covers the area of treatment of the patient and generates a 3D gradient field for remote-controlled movement and orientation of an endorobot. The endorobot is provided with a linear magnet and is freely movable in the hollow organ. Further, the stent, which can be uncoupled from the outside, is secured to the endorobot in a folded-down state so that it can be brought to the site of use and can there be opened out so as to bear firmly on the wall of the hollow organ.

Device for introducing a stent into a hollow organ

A linear drive device comprising at least one excitation winding for producing a variable magnetic field and is provided with an associated yoke body conducting a magnetic flux and an armature body which comprises a magnet carrier provided with at least two permanent magnet parts, preferably in the form of a plate, and to which an axial oscillation movement can be transferred by the magnetic field of the excitation winding. In order to avoid eddy currents in the magnet carrier, it is made of an electrically insulating material at least in the part thereof which penetrates into the magnetic field area defined by the pole surfaces of the yoke body and the excitation winding or which are arranged in said area. The magnet parts can be provided with ferromagnetic covers.

Linear drive device provided with an armature body having a magnet carrier

In a method for the operation of a magnetic resonance apparatus having a gradient coil system as well as a shim system with a number of shim plates with respectively allocated heaters, at least one information signal indicating a change in shape and/or position of the gradient coil system is determined or employed, the regulation of the heaters, and thus the temperatures of the respective shim plates ensuing dependent thereon.

Magnetic resonance apparatus and operating method therefor for actively regulating heating in the apparatus

A magnetic resonance apparatus has a basic field magnet with an inner unit, an outer unit and at least one middle unit that are essentially hollow-cylindrical and are electrically conductive and that are arranged inside one another such that the inner unit is enveloped by the middle unit and the middle unit is enveloped by the outer unit, and a gradient coil system which induces eddy currents at least in regions of the outer unit. At least the inner cylindrical jackets of the units are matched to one another in term of mechanical properties according so that the middle unit effectively damps oscillatory transmission from the outer unit to the inner unit that would otherwise occur due to magnetic coupling.

Magnetic resonance apparatus having a basic field magnet with damping of mechanical oscillations

An X-ray tube has a cathode and an anode arranged in a vacuum housing, the electron beam emanating from the cathode proceeding through a hollow cylindrical housing part of the vacuum housing to the anode. An electromagnet is provided for the deflection of the electron beam. The electromagnet has a U-shaped yoke with two legs having first ends connected to one another by a base section and having a winding surrounding the base section. The legs straddle the housing part and the electromagnet is disposed so that the electron beam is spaced a distance from the second ends of the legs so that from the second ends of the legs so that the electron beam is situated only in the stray field of the electromagnet, rather than in the region of maximum field strength.

X-ray tube

A magnetic bearing element contains a first bearing part attached to a shaft and a second, fixed-position, bearing part surrounding the first bearing part. One of the bearing parts contains an arrangement of a plurality of alternately polarized permanent magnetic elements between which there are ferromagnetic elements and the other bearing part contains a superconducting structure. This superconducting structure should have grains made of high-T.sub.c superconducting material, whose respective grain size is larger than the thickness of each of the permanent magnetic elements. In addition, the rotor shaft should be made of a non-magnetic material. The rotor shaft may contain the bearing part with permanent magnetic elements or the structure with the high-T.sub.c superconducting material.

Magnetic bearing element for a rotor shaft using high-T.sub.C

A magnetic resonance imaging apparatus for producing tomograms has a C-magnet with substantially planar pole faces for generating a magnetic field in the direction of the z-axis of a Cartesian coordinate system, for examining a human body having a body axis extending in the direction x-axis, the region to be examined being disposed between the pole pieces, gradient coils substantially parallel to the pole pieces, and a regulator for controlling the gradient currents of the gradient coils using the magnetic flux associated with each gradient coil as the measure value effecting such control. The gradient currents are adjusted dependent on disturbances in the magnetic flux which are caused by eddy currents and saturation effects in the ferromagnetic material in the proximity of the pole faces. Such a regulator can also be used in combination with gradient coils for generating a gradient in the z-direction for compensating for transient inhomogeneities in the main magnetic field.

Magnetic resonance imaging apparatus with regulator for reducing eddy

A gradient coil assembly for a magnetic resonance imaging apparatus includes respective gradient coils for the x-gradient and y-gradient which are flat coils provided at the respective planar pole surfaces of the fundamental field magnet. The gradient coils each consist of a number of turns, each turn including a straight conductor element and a return element which proceeds as azimuthally relative to the edge of the coil. The assembly also includes correction coils formed by two identical conductor segments, each segment contain arcuate conductor groups which are provided for correcting the linearity of the gradients in the edge regions of the gradient coils.

Gradient coil assembly for a magnetic resonance imaging apparatus

A magnet system for a nuclear spin tomography installation contains annular superconducting coils for generating a magnetic background field and nonsuperconducting gradient coils. A hollow cylindrical thermal shield fits between the gradient coils and the superconducting coils. According to the invention, the thermal shield at the front faces is formed from tubular end pieces. The front faces have a greater specific electrical resistance than a tubular intermediate piece of the thermal shield that extends between the end pieces and cover at least the area of the gradient coils.

Magnet system for nuclear spin tomography having superconducting coils

A quench propagation device for a superconducting magnet having at least one pair of superconducting coils operates so that in the event of a transition to normal-conductance (quench) of a first coil of the coil pair, which up to that point was superconducting, the second coil of this pair is also converted from the superconducting operating state to the normal-conducting state using heating arrangements thermally connected to the coils. This device is constructed so that in the event of a quench rapid magnet de-excitation and uniform current distribution and, consequently force relationships, are achieved. The heating arrangements include two auxiliary windings magnetically closely coupled with their particular assigned coils of the coil pair. The auxiliary winding material is a discrete normal-conducting conductor having a predetermined specific electrical resistance. The two auxiliary windings are short-circuited with each other so that the direction of current flow in one auxiliary winding is opposite to the direction of current flow in the second auxiliary winding.

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Erlangen, Germany

Guenter Ries