Abstract: A method for operating a linear compressor including a linear drive with a stator and a rotor configured for displacement by a magnetic field of the stator against a spring force, and a compression chamber which is delimited by a displaceable piston coupled to the rotor during the operation of which an alternating current is applied to the stator in order to drive the rotor in an reciprocatingly, the method including the steps of applying, prior to operation, a direct current with a first polarity to the stator in order to displace the rotor from a rest position, measuring a first end position attained by the rotor under the action of the direct current, and controlling, during operation, the intensity of the alternating current with which the stator is excited in a manner wherein the rotor does not reach the first end position or reaches it at a reduced speed.

Abstract: A reversing linear drive which comprises a field coil and a magnetic armature that is excited by the magnetic field of the field coil to perform a linear, axially oscillating movement. In order to detect the armature position, the drive is provided with a stripe pattern element with an alternating arrangement of transparent and opaque stripes or of light-reflecting stripes and non-light-reflecting stripes which extends at least across the entire axial armature stroke, and with a light barrier with elements that emit and receive light in a direction perpendicular to the axial direction.

Abstract: In a method for local reduction of the operating noise produced by a medical diagnostic or therapy device, antisound is produced locally by a sound source. The sound source used is a highly directional parametric loudspeaker. As a result, disturbing operating noises can be limited locally and suppressed effectively.

Abstract: A shock wave source has a coil carrier, a coil, having a metallic membrane separated from the coil in insulating fashion for generating shock waves. The coil carrier is formed of a material that damps the formation and/or the propagation of audible acoustic waves in the generation of shock waves.

Abstract: A shock wave source has a coil carrier, having a longitudinal axis, a coil and a metallic membrane separated from the coil in insulating fashion for generating shock waves. The coil carrier has a generated surface, a first cover surface facing toward the coil and a second cover surface facing away from the coil. For reducing the low-frequency sound generation when generating shock waves, a cross-sectional area of the coil carrier intersected at a right angle by the longitudinal axis has a non-circular contour. A reduction of the audible sound generation when generating shock waves can also be achieved when the second cover surface of the coil carrier is non-flat.

Abstract: 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.

Abstract: A device provides ultrasonic therapy to a female breast. To this end, the breast is introduced into a container which, for a good acoustic coupling, is filled with at least one liquid. An ultrasonic transducer emits sound into the breast in a region which, in the positive and negative direction of rotation, related to the plane of the body of the female patient, covers angles of less than or equal to 50°. In a preferred embodiment, a compression pad and a fixing membrane are provided for fixing a position of the breast.

Abstract: An amplifier and a coil are electrically connected to an amplifier in a coil system. A current controller is provided for adjustment of the current which is supplied from the amplifier to the coil. The current controller adjusts the current such that, at least on average, a predetermined power loss is converted to heat in the coil.

Abstract: In a method for local reduction of the operating noise produced by a medical diagnostic or therapy device, antisound is produced locally by a sound source. The sound source used is a highly directional parametric loudspeaker. As a result, disturbing operating noises can be limited locally and suppressed effectively.

Abstract: 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.

Abstract: An amplifier and a coil are electrically connected to an amplifier in a coil system. A current controller is provided for adjustment of the current which is supplied from the amplifier to the coil. The current controller adjusts the current such that, at least on average, a predetermined power loss is converted to heat in the coil.

Abstract: A shock wave source has a coil carrier, a coil, having a metallic membrane separated from the coil in insulating fashion for generating shock waves. The coil carrier is formed of a material that damps the formation and/or the propagation of audible acoustic waves in the generation of shock waves.

Abstract: A shock wave source has a coil carrier, having a longitudinal axis, a coil and a metallic membrane separated from the coil in insulating fashion for generating shock waves. The coil carrier has a generated surface, a first cover surface facing toward the coil and a second cover surface facing away from the coil. For reducing the low-frequency sound generation when generating shock waves, a cross-sectional area of the coil carrier intersected at a right angle by the longitudinal axis has a non-circular contour. A reduction of the audible sound generation when generating shock waves can also be achieved when the second cover surface of the coil carrier is non-flat.

Abstract: An ultrasound transmitting configuration includes at least one ultrasound generating device for exposing a medium which has an acoustic medium impedance and a medium speed of sound to ultrasonic waves. The ultrasound generating device has at least two ultrasound transducers which can be excited through actuating electrodes for emitting ultrasound and which have an acoustic transducer impedance. The ultrasound transducers are separated from one another and disposed alongside one another. An ultrasound lens which has an acoustic lens impedance and a lens speed of sound is disposed between the ultrasound generating device and the medium. The ultrasound generating device is acoustically coupled on a coupling side to the ultrasound lens. The ultrasound transducers extend toward the medium over a transducer depth, they extend toward one another over a transducer width, and they extend at right angles to both the transducer depth and the transducer width over a transducer length.

Abstract: A method and an apparatus for local heating and global monitoring of a tissue disposed in an imaging device, monitored by the imaging device and substantially simultaneously heated by focused ultrasound from an appropriate source. The ultrasound is generated outside the imaging device and is guided to the tissue through the use of a waveguide. In particular, the imaging device is a magnetic resonance scanner.

Abstract: An apparatus for fixing a female breast for use in a variety of medical-technical applications such as, for example, ultrasound therapy, ultrasound diagnosis or biopsy. The fixing apparatus includes a container, into which the breast is introduced, a fixing diaphragm, and at least one compression cushion. The compression cushion presses the breast against the fixing diaphragm thereby achieving a fixed position of the breast.