Abstract: A motion correction method and related analog motion correction circuitry are disclosed, which correct for image blurring due to patient movement in scintigram heart studies using an Anger camera. X, Y positional coordinate signals developed for incident quanta of radiation E1 emitted by an isotope of energy 1 distributed in the heart are displayed on a CRT screen after correction in accordance with the displacement from an initial position X.sub.o ', Y.sub.o ' of a centroid calculated from X', Y' positional coordinate signals developed for incident quanta of radiation E2 emitted by isotope of energy 2 in the form of a point source strapped to the patient's chest for movement therewith.

Abstract: Counts of a gamma camera, acquired during a nuclear cardiac structure examination, which represent time-activity curves at different locations of a pixel matrix of the cardiac structure are fitted to a cosine wave function. From said fitted function the wave amplitude, phase, and an error value (representing the reliability of the acquired time-activity curve) are extracted. Finally, for each location in the pixel matrix said extracted values are simultaneously displayed as they are acquired.

Abstract: A thermoluminescent radiation detector crystal which has been irradiated by ionizing radiation is contacted with an organic solvent at its boiling point prior to read-out of the crystal. The boiling point of the solvent is approximately equal to the optimum post-radiation annealing temperature of the crystal. The solvent thereby simultaneously cleans and anneals the crystal. Preferably, the contacting step is performed by suspending the crystal in vapors of the solvent. The vapor condenses on the crystal and washes away impurities from the surface thereof.

Abstract: The radiation detector basically contains a vacuum window supported by a vacuum tight envelope, a scintillator, an interface, a photo-cathode, preferably a grid, an electron multiplier such as a multichannel plate, and a location sensitive detector. The radiation detector is particularly useful in generating two-dimensional images in nuclear medicine.

Abstract: The apparatus forms a profilated collimator strip out of a band of deformable material. It contains a first and a second forming tool, both of which contain a row of forming teeth. The teeth may be hexagonal to form corresponding deformations having sidewalls greater in width than the top or bottom walls. In operation, the teeth are disposed oppositely and staggered with respect to each other. The apparatus also contains a device for performing a relative movement between the two tools, whereby the tools approach each other. The apparatus also includes a device for moving one of the tools parallel to the other one in an indexing step by step motion. In the method for forming a profilated collimator strip, a band is placed on one tool, whereby a portion of the band is located in the space between the two tools which are positioned oppositely to each other. Then the tools are approached to each other, the teeth thereby pressing the band into the predetermined shape.

Abstract: From a heart sound signal input the occurrence of a first occurring heart sound is detected. Thereupon a predetermined heart sound enable window time is established, which for a first detection cycle is set to approximately the diastolic interval for the maximum heart rate to be detected. If a second heart sound occurs within this heart sound enable window time, this second heart sound is detected as a systole heart sound. The first heart sound may be detected as a diastole heart sound. If a second heart sound does not occur within the heart sound enable window time the procedure is repeated with increasing heart sound enable time as long as a second heart sound occurs within an increased heart sound enable window time.

Abstract: A mechanism is provided for mounting a detector head including a collimator onto supporting structure of a radiation detector for rotation about a selected one of a plurality of trunnion axes, the selection being made so that rotation occurs about the trunnion axis which passes nearest to the center of gravity of the head. A first rotatable member is mounted to the supporting structure for rotation about a first trunnion axis and a second rotatable member is mounted to the first rotatable member for rotation about a second trunnion axis. A key mounted on the first rotatable member shifts between protrusion into a first key slot located on the supporting structure and a second key slot located on the second rotatable member. The shifting mechanism is locked when the detector head is in a position other than a collimator changing position.

Abstract: The apparatus contains a detector for detecting radiation emitted from an object under examination, and a device associated therewith for forming an imaging signal. The imaging signal is composed of a sequence of individual image signals each of which represents an individual radiation image of the object under examination. The imaging signal comprises a first individual image signal and second individual image signals following the first individual image signal. The apparatus also contains a signal processing circuit for processing the imaging signal and for forming a display signal thereof, and a display device for receiving the display signal and for displaying a sequence of images of the object under examination. In particular, the signal processing device basically contains three functional elements, that is a storage device, a subtractor, and an evaluation circuit. The storage device is provided for storing the first individual image signal, thereby forming a reference image signal.

Abstract: The method and apparatus furnish difference images from a video signal which contains a sequence of images that are obtained from a patient under examination. First a first of the images contained in the video signal is recorded in a first storage device. Thereby a so-called primary mask is formed. Then, a subsequent second of the images contained in the video signal is recorded in a second storage device. Subsequently, a third of these images is recorded in a third storage device. From here on, images contained in the video signal following the third image are recorded alternatingly in the second and the third storage device. At a certain point of time, a signal for starting data acquisition is provided. Simultaneously or thereafter, a so-called secondary mask is selected. The secondary mask is an image completely recorded in the second or third storage device shortly prior to the generation of the data acquisition signal.

Abstract: A test pattern device for testing scintillation cameras has a radiation transparent body member with internal mercury-filled communicating passages that define a calibrated radiation opaque test pattern. A peripheral passage serves as a mask to outline the useful field of view of the camera crystal, and expansion chambers accommodate changes in mercury volume due to temperature. The body member is made by securing a plastic cover plate to a plastic base molded with grooves to form the test pattern passages and filling ports, and then sealing the filling ports after mercury has been added to fill the passages. The invention avoids the tolerance problems associated with the manufacture of conventional lead test pattern devices.

Abstract: A collimator is disclosed which has a stack of radiation opaque plates that is tilted to vary the angle of view of the scintillation crystal of a radiation detector with respect to a radiation source. The plates have hexagonal apertures that are aligned with corresponding apertures on adjacent plates to provide radiation transmitting channels. As the stack is tilted, the plates slide laterally over one another to change the slant of the channels.

Abstract: An improved emission computerized tomography (ECT) drive mechanism for an Anger-type scintillation camera is disclosed. A support arm, carrying the camera head at one end and a counterweight at the other, is mounted on a universal joint and driven about the joint by a crank. The crank comprises an acme-type screw and the arm attaches to the crank at a point distant from the joint by means of an acme nut. The tilt angle of the arm is varied by varying the position of the acme nut on the acme screw.

Abstract: A phased array transducer is disclosed for transducing ultrasound of a predetermined frequency. The transducer includes a number of piezoelectric elements, all having the same natural frequency, and having two surfaces located opposite to each other, each provided with an electrode. The distance between the two surfaces of each element is one quarter of the wavelength of the ultrasound produced by the transducer within the piezoelectric material.

Abstract: A dynamically variable electronic delay line for real time ultrasonic imaging systems is disclosed which controllably phases the signals associated with an array of electromechanical transducer elements and thereby enables selective scanning and dynamic focusing of a target. A controllable variable electronic time delay apparatus is coupled to each of the electromechanical transducer elements of the array having separate write-in and read-out addressing capabilities. The signals associated with a respective ultrasonic transducer element are fed in at selected write-in addresses and subsequently read-out and extracted after an initial time delay interval. The write-in and read-out address pointers of the memory system are continuously sequenced during operation of the device and the time delay interval is a function of the difference between the addresses and the clock rate.

Abstract: The ultrasonic transducer contains a plurality of adjacently positioned piezoelectric segments which are arranged concentrically. Each of the segments contains a number of linear parallel grooves, whereby these grooves define spaced surface areas therebetween. Each of the surface areas comprises respectively a piezoelectric element. The individual grooves are approximately annular when the segments are assembled. They decouple the piezoelectric elements acoustically from each other. Preferably, the segments each have a triangular shape.

Abstract: A method and apparatus are disclosed for correcting energy (Z) signal non-uniformities in the response of an Anger-type scintillation camera to image events occurring at different (X, Y) positions on the camera face. Energy correction factors f(P)' corresponding to deviations of up to .+-.12.8% from a reference pixel area are determined off-line for 4,096 camera face pixel areas from a uniform flood field source Z-map. The correction factors f(P)' are stored in a 64.times.64 array of a correction factor memory, addressable by image event (X, Y) position coordinates. During on-line operation, for each image event the correction factor f(P)' corresponding to the image event (X, Y) position is retrieved, scaled in a multiplying digital to analog converter by the actual energy Z.sub.IN of the event, and added to the event Z.sub.IN signal to provide a corrected energy signal Z.sub.c =Z.sub.IN (1+f(P)') which is proportional to the incoming signal.

Abstract: A method and apparatus for the dynamic modification of the spatial distortion correction capabilities of a scintillation camera having spatial distortion correction apparatus. The spatial distortion correction apparatus includes a memory having stored therein spatial distortion correction factors in a predetermined addressable format. During the on-line use of the scintillation camera, the spatial distortion correction apparatus transforms the image event coordinate position data from the scintillation camera in accordance with the stored distortion correction factors to provide corrected image event coordinate repositioning data. The spatial distortion correction modification apparatus and method provides modification of the corrected image event coordinate data in accordance with the respective energy levels of the image events to provide accurate spatial distortion correction characteristics for the actual energy levels of the image events.

Abstract: A method and apparatus for correcting for the spatial distortions of scintillation cameras or similar image forming apparatus. The spatial distortion correction method accurately and precisely determines distortion correction factors in an off-line test measurement and analysis phase prior to actual on-line diagnostic use. The distortion correction factors are initially determined from image event data that is obtained during the test measurement phase by orthogonal line pattern images. Data from a uniform field flood image is also utilized during the test measurement phase to refine and modify the distortion correction factors utilizing the gradient of a function of the field flood image data. Scintillation camera image repositioning apparatus is provided and includes a memory having the correction factors stored therein in a predetermined array.

Abstract: A dynamically variable electronic delay line for real time ultrasonic imaging systems is disclosed which controllably phases the signals associated with an array of electromechanical transducer elements and thereby enables selective scanning and dynamic focusing of a target. A controllable variable electronic time delay apparatus is coupled to each of the electromechanical transducer elements of the array having separate write-in and read-out addressing capabilities. The signals associated with a respective ultrasonic transducer element are fed in at selected write-in addresses and subsequently read-out and extracted after an initial time delay interval. The write-in and read-out address pointers of the memory system are continuously sequenced during operation of the device and the time delay interval is a function of the difference between the addresses and the clock rate.

Abstract: A system and method for obtaining a nuclear kymogram of regional wall motion of an organ under study such as a human heart includes injecting a radioisotope into the blood stream which accumulates in the cardiac blood pool or myocardium. A scintillation camera having a reduced generally elongated area of data recordation is positioned overlying a selected portion of the heart and positional "events" occurring along the major axis of the area of recordation are swept across a CRT in synchronism with the ECG signal. Successive real-time displays each in synchronism with the ECG signal are accumulated to provide a nuclear kymogram.