Abstract: An apparatus for medical diagnosis and/or therapy includes an electromagnetic obstacle sensor in order to prevent collisions with, for example a patient to be examined. The sensor is constructed so as to include a radiation transmitter and a radiation receiver in the form of capacitive electrodes 16 and 18, respectively, whereto electronic circuits 26 and 28 for signal processing are connected. In order to enable the electrodes 16 and 18 and the electronic circuits 26 and 28 to be checked for correct operation, a test electrode 14 is connected between the transmitter electrode 16 and the detection electrode 18, which test electrode can be connected, if desired, to a point 32 of fixed voltage via a controllable switch 34. The presence of an obstacle is thus simulated. The output signal of the electronic circuits 26 and 28 can be checked to determine whether this output signal corresponds to the situation in which an obstacle is present.

Abstract: For the display of images, notably X-ray images, the complete image of full resolution, usually consisting of a group of images, may be substantially larger than the size that can be reproduced on a display screen. In accordance with the invention, the overall group of images is displayed on the display screen as an auxiliary image in a strongly reduced scale, the size of the auxiliary image being dependent on the group of images. Via a frame which is reproduced in the auxiliary image and whose dimensions and position can be varied, a part of the group of images, i.e. one image or separate neighboring images, is selected and displayed on the overall display screen. When the frame is shifted in the auxiliary image, the part of the overall group of images which is displayed on the display screen is also automatically shifted.

Abstract: A magnetic resonance device has a main field magnet system which generates a steady magnetic field in an examination zone. The main field magnet system includes a yoke structure which consists of two yoke plates and a yoke wall interconnecting the two yoke plates, a pole block which is arranged inside the yoke device, and below an examination zone, and a coil which is arranged within the yoke system and above the examination zone. In order to ensure that a patient present in the examination zone can also undergo further treatments and is freely accessible during an MR examination, the inner space of the coil as well as the space between the coil and the examination zone remains free from components of the magnet system, the coil being constructed so as to be ring-shaped and encloses the examination zone essentially in such a manner that the patient is freely accessible from above and from the sides.

Abstract: An invasive device which is intended to cooperate with a magnetic resonance imaging apparatus is provided with an RF coil which is situated near a distal part of the invasive device. The RF coil is used so as to visualize the position of a distal end of the invasive device, introduced into an object, in an image of the object. Current induced by an RF field to be generated by the magnetic resonance imaging apparatus develops heat in the electric connection between the RF coil and a control unit, which may be annoying to a patient. In order to counteract the development of heat in the invasive device, the invasive device is provided with a hollow carrier. The electric connection extends through said carrier which is provided with an electrically conductive shield with an additional resistance.

Abstract: An MR apparatus which includes a cylindrical coil system and a surface coil system. In order to form a coherent MR image of an as large as possible examination zone by means of an MR apparatus, without necessitating the use of a larger number of receiving channels with respect to a conventional MR apparatus, the cylindrical coil system, for example a bird-cage resonator, and the surface coil system, for example a quadrature coil system, are arranged to overlap and the magnitude of the region of overlap can be varied in order to reduce mutual coupling.

Abstract: A method for the temporal filtering of a sequence of digitized noisy images includes the evaluation of an anti-causal filtered sample (P.sub.t.sup.A) in order to reconstruct a present noisy sample (I.sub.t.sup.P) of a given pixel in a present image by an anti-causal linear combination of a causal filtered sample (P.sub.t.sup.C) obtained by preliminary causal linear temporal filtering in association with coefficients (b.sub.j.sup.C) and an anti-causal noisy sample (I.sub.t+1.sup.A). To the samples (P.sub.t.sup.C, I.sub.t+1.sup.A) there are assigned weights calculated as functions of a causal gain factor (K.sub.t.sup.C), equal to the inverse of the sum of the coefficients of the causal linear filtering, and an anti-causal continuity coefficient (.alpha..sub.t.sup.A), the weight of the anti-causal sample (I.sub.t+1.sup.A) being equal to the probability of intensity continuity between the anti-causal sample (I.sub.t+1.sup.A) and a previous filtered sample (P.sub.t.sup.C, P.sub.t-1.sup.C) in the sequence.

Abstract: A method for the temporal filtering of an image of a sequence of noisy digitized images includes the evaluation of an integration equation which produces the filtered intensity (P.sub.t.sup.C) of a given pixel ?A.sub.t (x,y)! in the present image (J.sub.t.sup.P) by evaluating the sum of the noisy intensity (I.sub.t.sup.P) of the present (t) and the product of a gain factor (K.sub.t.sup.P) and the difference of said noisy intensity of the present (I.sub.t.sup.P) and the causal filtered intensity (P.sub.t-1.sup.C). According to this evaluation, the gain factor (K.sub.t.sup.C) is a function of the causal gain factor (K.sub.t-1.sup.C) and of a continuity coefficient (.alpha..sub.t.sup.C) which measures the probability of intensity continuity between the present noisy intensity (I.sub.t.sup.P) and the causal filtered intensity (P.sub.t-1.sup.C). A device for carrying out this method includes a sub-assembly whose input (100) receives the present noisy sample (I.sub.t.sup.

Abstract: A device for imaging a turbid medium, for example a breast of a female, includes a holder for receiving the turbid medium, a light source, a photodetector and a processing unit for deriving the image from the intensities measured. The holder is adapted to receive besides the turbid medium also an adaptation medium having substantial identical optical parameters as the optical parameters of the turbid medium. In this way artefacts in the reconstructed image due to the boundary effect between the turbid medium and the holder can be reduced. When a liquid is used as the adaptation medium a perfect match between the holder and the shape of the turbid medium can be obtained. Further, also intensity differences in the image due to different path lengths between light source and photodetector can be equalized.

Abstract: An x-ray examination apparatus includes an x-ray source for emitting x-rays and an x-ray detector for deriving an image signal from an x-ray image. The x-ray detector has a semiconductor element including one or several sensor elements. Further the x-ray examination apparatus is provided with a bias radiation source for irradiating the x-ray detector with electromagnetic radiation. In particular, the x-ray detector is an x-ray sensor matrix having a multitude of semiconductor sensor elements. Preferably the bias radiation source is arranged to emit infrared radiation.

Abstract: A patient (7) is irradiated by an X-ray source (1) in a computed tomography apparatus. The radiation is subsequently detected by the detector cells (5) of a position-sensitive X-ray detection system (4) and the intensities detected are applied to a computing device (16). Absorption as well as elastic and inelastic scattering of X-rays occur within the patient (7). The data acquired is corrected for elastic (coherent) scatter by deriving a deconvolution function from the elastic scatter function, which deconvolution function is applied to the data. The elastic scatter function is determined, for example by a computer simulation.

Abstract: An image guided surgery system includes a position detection system which has a camera unit (1) and which measures positions of markers on the patient (12) and of a surgical instrument (11). The image guided surgery system also includes a transformation unit (30) which automatically derives the mapping associated with imaging of the patient. The imaging is for example performed by way of x-ray computed tomography or magnetic resonance imaging. The transformation unit (30) is arranged to match positions on the patient (12) to positions in the image. To that end the transformation unit computes the minimum of a cost function.

Abstract: A method of imaging an interior of a turbid medium, for example a part of a breast of a human female, the turbid medium is irradiated with light and measurement of the intensity of light propagated along a plurality of light paths through the turbid medium is measured. An image of the interior of the turbid medium is reconstructed from the intensities measured. Furthermore, possible strengths assignable to each pixel of the image are determined from combinations of weighting functions and differences between expected photon fluences and a measured photon fluences from the intensities measured. A distribution function is made up from the possible strength determined. In a last step the image is determined from the distribution function. Further steps can be carried out to correct for objects of high strength in the image.

Abstract: A collision warning system is for a head mounted display (HMD) (10) worn by a user, for example as the interface to a virtual reality system, to warn of nearby objects in the physical environment. A motion detector (30,32) detects positional changes of the HMD, which changes are reflected in changes of a displayed image viewpoint, and a comparator stage (38,40) determines whether the movement takes the user into a "prohibited" area. If so, a visual and/or audible warning is provided to the user via the HMD (10). In an embodiment, the display screens (18) of the HMD include liquid crystal display shutters (20) which are switched to a transparent state in the event of an imminent collision such that the user is not only warned of the danger but also able to see it without having to remove or adjust the HMD.

Abstract: A video level measuring apparatus for use in conjunction with setup and maintenance of an imaging system, such as an X-ray imaging system, is configured for first and second modes of operation. In the first mode of operation, a measure signal indicative of the average video level of the portion of an input video signal produced by the imaging system within an operator positionable and sizable window area is formed and converted to a numeric displays and an augmented video signal is presented as an output video signal in which the window area of the corresponding image has a video level which is increased by a uniform adjustable amount. In the second mode of operations, a test pattern video signal corresponding to an operator positionable and sizable window of uniform operator adjustable brightness against a black background is presented as the output video signal applied to a monitor.

Abstract: An ultrasonic echography system includes a probe (1) which is connected to an echograph provided with a transmission stage (32), receiving and processing stages (34, 38) for ultrasonic echo signals, and a device (21) for displaying images of an artery. The probe (1) is formed by three integral transducers, i.e. a first, central transducer (2) for scanning the artery axially and two lateral, further transducers (3, 4) which are arranged parallel to one another and oriented perpendicularly to the first transducer in order to form transversal sectional images of the artery. The echograph also includes a sequence for sequentially activating each of the three transducers in a cyclical manner.

Abstract: The invention provides an operating microscope for observing an operating field and also for producing a three-dimensional visualization of image data of the operating field or also of a vicinity of the operating field. The user of the operating microscope, for example a surgeon, can observe a three-dimensional visualization of image data during use of the operating microscope, said image data having been acquired by computerized tomography (CT) or magnetic resonance imaging (MRI) and being stored in an image memory. Preferably, an image processing unit derives a stereoscopic image of the operating field from the stored image data, which stereoscopic image is coupled into the binocular of the operating microscope. The user can then optionally observe the actual operating field or a perspective image formed by means of the registered image data.

Abstract: In a system for recording and displaying still and moving images, the still images are recorded on a record carrier (8) in a loss-free manner and with a low compression factor, whereas the moving images are recorded with a high compression factor and an algorithm which is not loss-free. For medical images, for example cardiac images, processing of the images prior to display is desirable. For the moving images the image processing (5) is performed prior to compression (4) and recording (7). For the still images the processing (19) is performed after the images have been read from a record carrier (8) and reconstructed. A raw version of the loss-free still images thus remains available for analysis (20).

Abstract: An imaging arrangement including a multi-sensor for use in an x-ray examination apparatus is described that combines a plurality of partially overlapping sub-images, resulting in an increased effective sensor area when compared to a single sensor-image. Thus an imaging arrangement is provided suitable for imaging a large area output screen of an image intensifier by way of semiconductor image sensors. Image artifacts owing to variations in the alignment of the respective image sensors are corrected for by applying geometric transformation to respective electronic sub-image generated by the image sensors. The transformed electronic sub-images are assembled into a recombined image. Further image quality improvement is obtained by performing evening operations in overlapping regions of the transformed sub-images.

Abstract: The invention relates to a high-voltage connector, consisting of a plug member and a receptacle member receiving the plug member, the area of the plug member facing the receptacle member and/or the area of the receptacle member facing the plug member being provided with a layer of an elastomer. A particularly high high-voltage strength is achieved in that the elastomer is made to swell by means of a swelling medium. The invention also relates to an X-ray generator comprising such a high-voltage connector and to a method of manufacturing such a high-voltage connector.

Abstract: An X-ray apparatus includes an X-ray source with an X-ray tube (2) arranged in a protective tube housing (1) and a filament converter which is connected to the cathode (3) of the X-ray tube (2) and accommodated in the protective tube housing (1). Because of its volume, the filament converter usually cannot be accommodated in the protective tube housing (1) of conventional X-ray apparatus unless major structural modifications are made. However, the use of attenuated high-voltage cables at the cathode side is then impossible still. The invention utilizes a filament converter in the form of a coreless filament transformer (14, 15, 16, 17) and the primary coil (14, 16) of the filament transformer is arranged so as to be coaxial with the secondary coil (15, 17) of the filament transformer. Moreover, the two coils are arranged around a carrier (5, 10), which is preferably the high-voltage connection socket (10) or the tube neck (5).