Roger E. Arseneau has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
Abstract: Signal processing circuitry for use in medical imaging includes a flash analog-to-digital converter (FADC) for digitizing signals from a sensor; a memory for storing a plurality of digitized signals prior to a current event; and a processor for generating an adjustment signal from the plurality of digitized signals to adjust a first signal corresponding to the current event. In a fast time scale event processing, the signal processing circuitry generates an adjustment signal in near real-time corresponding to an analog error which is computed and updated from signals just prior to an event. In an alternative embodiment, the signal processing circuitry includes an FADC which generates the plurality of signals from a plurality of pseudo-event signals; and a digital-to-analog converter (DAC) is used for generating the pseudo-event signals between a previous event and the current event.
Abstract: A signal containing piled-up pulses from a scintillation camera head is sampled at a high frequency. Samples are summed to provide a time-integration of pulses which are sampled. When pulses pile up, the tail of the first pulse can be determined by extrapolation, permitting the first pulse to be energy-validated. The overlapping tail of the first pulse and the head of the second pulse are also time-integrated, and the area of the tail of the first pulse is subtracted from the time-integration so obtained. It is then possible to validate the second pulse.
Abstract: A method and integrator circuit for digitally integrating signals wherein digital signals to be integrated are supplied to a digital adder thereby generating digital adder output signals. Each digital adder output signal is stored and the stored digital adder output signal is refed to the digital adder. Each refed stored digital adder output signal is then added by the adder to a succeeding digital signal supplied to the adder for integration. In a preferred embodiment of the invention, the digital signals are analog-to-digital converted signals produced by a radiation detector, such as a scintillation gamma camera, generated from radiation impinging on the radiation detector.
Abstract: Improved detection circuitry is disclosed for calculating the position on the crystal of a scintillation event in a scintillation camera. Electrical signals developed by photomultiplier tubes for successive events are weighted by a resistor matrix and transferred to integrators which develop event position signals based on the quanta of radiation incident on the scintillation crystal. To improve the count rate without sacrificing the resolution, parallel integrators are provided so that a second integrator can integrate electrical signals from a second scintillation event during the time that a first integrator is processing the signals from a first scintillation event. Common storage buffers are connected to the integrators to hold the integrated signals for further processing.
Abstract: An improved threshold preamplifier circuit is disclosed for use with the event X, Y position detection circuitry of a scintillation camera. Threshold amplifiers, having a common threshold voltage that is set as a function of the energy of the incident scintillation event, control the respective preamplified photomultiplier tube output signals so that signals from tubes close to the event receive greater weight in the X, Y position analysis than signals from distant tubes. In a preferred embodiment, the threshold voltage is determined by the output of a summing amplifier which sums an unthresholded energy signal Z.sub.nt which represents the total energy of the incident event, an integrated energy signal Z.sub.u which represents the integrated value of the unthresholded energy signal Z.sub.nt, and a constant voltage which represents the preselected zero energy level threshold biasing voltage. Variable resistors control the relative contributions to the summing amplifier input of the Z.sub.nt and Z.sub.
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.
November 20, 1979
Date of Patent:
February 16, 1982
Siemens Gammasonics, Inc.
Anthony P. Del Medico, Roger E. Arseneau
Abstract: A scintillation camera is provided with electrical components which expand the intrinsic maximum rate of acceptance for processing of pulses emanating from detected radioactive events. Buffer storage is provided to accommodate temporary increases in the level of radioactivity. An early provisional determination of acceptability of pulses allows many unacceptable pulses to be discarded at an early stage.