Siemens Aktiengesellschaft

Dietrich Hassler

Erhard Schmidt

Martin Hoheisel

Helmut Reichenberger

Hubert Schwark

Fritz Breimesser

Georg Naser

Franz Grasser

Wolfgang Haerer

Georg Koehler

Eckart Hundt

Elmar Trautenberg

Klaus Killig

Heinz Eschenbacher

Guenter Temme

Gerd Maderlechner

Peter Wegener

An image detector for X-ray technology enables different image resolutions in a simple way. In an a-Si:H detector matrix, several pixels can be fixed via a row lead and a column lead, and these pixels can be interrogated together or, by the use of voltage impulses of different levels or polarity, can be interrogated separately.

Image detector with selective readout of pixels in groups or individually

An x-ray image-generating system having an a-Si:H detector matrix is constructed so that different enlargements are possible with a small number of terminal conductors. Two groups of pixels of the detector matrix can be read out together by means of voltage pulses of different levels, respectively applied in alternation to the two pixel groups on a line conductor common to both pixel groups.

Readout system for a solid state image converter

An x-ray diagnostic installation has a high-voltage generator, an x-ray tube supplied by the high-voltage generator, and a solid-state image converter on which x-rays, attenuated by an examination subject disposed between the x-ray tube and the solid-state image converter, are incident. A control unit is connected to the high-voltage generator and to the solid-state image converter, and controls the high-voltage generator to cause the x-ray tube to emit a first x-ray pulse of a short duration which produces an x-ray exposure in the solid-state image converter. The control unit conducts a read out of the solid-state image converter to obtain a measured value representative of the x-ray dose rate, the control unit using this measured value to calculate the x-ray transparency of the examination subject and, from the x-ray transparency, to calculate an optimum x-ray dose. The control unit then operates the high-voltage generator to cause the x-ray tube to emit a second x-ray pulse, having the optimum x-ray dose, for acquiring a diagnostic image of the examination subject.

X-ray diagnostic installation having a solid-state image converter and

An x-ray diagnostics installation has a high-voltage generator for an x-ray tube for generating an x-ray beam, having a detector arranged in the x-ray beam for acquiring the x-ray dose, a control unit connected to the detector for the control of the high-voltage generator, and a solid-state image converter which also serves as the detector. The solid-state image converter has a semiconductor layer with light-sensitive pixel elements arranged in a matrix and an electrically non-conductive layer applied thereon, an electrode layer applied on the electrically non-conductive layer forming a capacitor with the pixel elements to which charge is supplied due to x-ray exposure and that is connected to the control unit for the acquisition of this charge corresponding to the x-ray dose.

X-Ray Diagnostics installation having a solid-state converter

An x-ray image sensor has a matrix of radiation-sensitive detector elements, the detector elements being connected in two groups to a common read-out line on which bipolar signals are generated. Read-out signals of one polarity cause read-out of one of the groups of detector elements and read-out signals of the other polarity cause read-out of the other group. An image detector having high resolution but low technical outlay is thereby achieved.

X-ray image sensor

A solid state image converter has light-sensitive cells arranged in a matrix, each cell formed by two oppositely-connected diodes, at least one diode in each cell being a photodiode, and has driver circuits for driving the diodes, that are connected between the respective row and column lines of the driver circuits. The driver circuits electrically reset the diodes individually or row-by-row by clocking. By briefly forward biasing, the individual photodiodes so that they are briefly brought into the conductive state, and are subsequently reverse biased. The solid state image converter can be continuously exposed with x-rays and is employable in an x-ray diagnostics installation.

Solid state image converter with two oppositely connected diodes wherein

An electromagnetic pressure pulse source for generating focused pressure pulses as an electrically conductive membrane and a coil system which drives the membrane by rapidly displacing the membrane from the coil system. The coil system is formed by an annular array having a number of annular zones which can be individually activated to cause the generation of pressure pulses in variable chronological relation to each other, which permits the location of the focus of the resulting shockwave to be adjusted with a range, and/or the diameter of the focus to be changed.

Electromagnetic pressure pulse source

An apparatus for generating acoustic rarefaction pulses, i.e., a negative pressure pulse, has a pressure pulse source and reflector having a negative reflection factor, and an acoustic propagation medium filling the space between the pressure pulse source and the reflector. The reflector has a boundary surface facing toward the pressure pulse source, consisting of a medium which is acoustically soft in comparison to the acoustic propagation medium. The boundary surface medium is separated from the acoustic propagation medium by a wall which is impenetrable by the acoustic propagation medium.

Apparatus for generating acoustic rarefaction pulses

For suppressing reflections of an acoustic reception signal at a transmitting/receiving ultrasound transducer, the ultrasound transducer is connected to a compensation circuit which supplies the ultrasound transducer with a compensation transmission signal during reception, which has a waveform similar to the acoustic reception signal, but with a polarity opposite that of the acoustic reception signal. A summing stage is connected in a reception channel of the ultrasound transducer, the summing unit having a first input supplied with a compensated reception signal, formed by a combination of the acoustic reception signal and the compensation transmission signal. A second input of the summing unit is connected to the compensation circuit, which supplies a signal at the second input which removes the contribution made by the compensation transmission signal from the compensated reception signal, so that the output of the summing unit generates a reception signal devoided of the compensation transmission signal.

Apparatus and method for suppressing reflections at an ultrasound

An ultrasound apparatus has a first group of transmission and reception channels that are respectively allocated to elementary transducer in the active aperture of a connectable transducer array. The central transmission location generated by a transmission channel and the reception location sampled by a reception channel coincide and lie on the allocated elementary transducer. In addition, a second group of transmission and/or reception channels is present, each being respectively simultaneously connectable to a plurality of elementary transducers via transmission and/or reception transfer stages for generating a virtual transmission and/or reception location that lies between the elementary transducers.

Ultrasound apparatus for the virtual diminution of the array division of

A method for generating an ultrasound image of a plane of a section of an examination subject having a non-uniform speed of sound distribution near the surface of the subject includes the steps of scanning the section plane line-by-line with a transducer array in an adaption phase and calculating values from the received, focussed echo signals which deviate from anticipated values which would arise given a uniform speed of sound distribution, the calculation being undertaken by a cross-correlation function of neighboring elementary transducers. Correction values are formed from the deviating values depending on the angle of incidence of the echo signals on the elementary transducers. In an imaging phase following the adaption phase, the delay values for focussing are modified dependent on the incident angle of the echo signals and dependent on the correction values for this incident angle. Image disturbances due to the non-uniform speed of sound distribution can thus be compensated even in the presence of thick, transducer-proximate disturbing layers in the examination subject.

Method for ultrasound imaging

In a method for calculating the flow velocity of, for example a blood stream, ultrasound pulses are repeatedly transmitted into an examination region with a spacing of a pulse repetition time (Tr). An autocorrelation function (Kii) and a cross correlation function (Kiq) in an environment (Tr.+-.1.5 T) around the pulse repetition time (Tr) are formed from the quadrature components (i, q) of echo signals of respectively successive transmission pulses. The shift of the maximum (.DELTA.t) of the correlation functions (Kii, Iiq) relative to the pulse repetition time (Tr) as a result of the velocity of the flow is fixed in a region (Bn) wherein the ambiguous, mean Doppler frequency (.omega.) identified in a traditional way lies. The apparatus for the implementation of this method comprises a shift identification circuit for this purpose. This shift identification circuit calculates the shift of the maximum (.DELTA.t) of one or both correlation functions (Kii, Kiq) relative to the pulse repetition time (Tr).

Method and apparatus for avoiding ambiguities in a pulse doppler

An apparatus for generating focused shockwaves, suitable for extracorporeal lithotripsy, has a substantially hollow-cylindrical membrane consisting of electrically conductive material and an electrical coil arrangement disposed inside the membrane which can be supplied with a high voltage pulse to rapidly repel the membrane and thereby generate a shockwave. The apparatus includes a concave reflector in the form of a paraboloid of revolution, which surrounds the membrane and coil, and which has a center axis substantially coincident with the center axis of the membrane. An acoustic propagation medium fills at least the volume between the membrane and the reflector. The shockwave generated by the cylindrical coil and membrane arrangement is reflected and focused by the paraboloid of revolution so that the shockwaves converge at a focus. The apparatus is arranged so that the focus conicides with a region of a patient to be treated with shockwave therapy, such as a calculus. The coil is wound in the shape of a cylindrical helix, and the membrane is in the form of a thin-walled, smooth tube.

Apparatus for generating focused shockwaves having a cylindrical coil

An extracorporeal lithotripsy apparatus for treating a calculus in the body of a patient has a shock wave source which generates shock waves converging in a focus zone, and an ultrasound locating system having a sector applicator with which at least the focus zone can be scanned. The sector applicator includes a number of ultrasound transducers, so that a number of layers, proceeding parallel to each other, can be quasi-simultaneously scanned. The number of layers which can be scanned corresponds to the number of ultrasound transducers. The layers are directly adjacent each other so that displacement of a calculus in the body during treatment in a direction transverse to the acoustic axes of the scanned sectors can be observed.

Extracorporeal lithotripsy apparatus with an ultrasound locating system

A shock wave source for use in lithotripsy has an electromagnetic shock wave source with the ultrasound head of an ultrasound locating system centrally disposed within the source. During locating of a calculus to be disintegrated, at least one surface normal of the exit face of the ultrasound head is aligned obliquely relative to the surface normal of the coupling surface of the shock wave source. Image disturbances due to multiple echoes are avoided by the oblique positioning of the ultrasound exit face.

Growing community of inventors

Uttenreuth, Germany

Dietrich Hassler