Abstract: A gamma camera having separate detectors respectively to determine the spatial location and energy of gamma radiation emanating from a patient is disclosed. The preferred camera has two adjacent, mutually perpendicular arrays of parallel, coordinant signal producing scintillaters positioned on the face of a scintillating energy crystal. Each of the fibers within the arrays conducts light resulting from Compton events to an associated one of a set of photodetectors to produce coordinant signals. Other photodetectors monitor the total scintillated energy within the energy crystal. The energy crystal is of sufficient size to absorb energy remaining in each patient emitted gamma ray that has produced Compton events in the coordinant scintillators. The sum of the energies of substantially coincident signals from the fibers and the crystal is used to identify photo peak events.

Abstract: An electronic gain control is disclosed for the photomultipliers of a gamma camera which assures that all photomultipliers in the camera have uniform gain for any given gamma event. A specific dynode in the photomultiplier is isolated from the line resistive voltage divider string in the photomultiplier which places each dynode under incremental voltages. A voltage is then applied to the isolated dynode which can vary anywhere from the voltage the isolated dynode would have had if inserted in the voltage divider string to the voltage that the immediately preceding or immediately succeeding dynode in the string has whereby the photomultiplier's gain is controlled. The applied voltage to the isolated dynode is developed electronically by a voltage to frequency converter coupled by an opto-isolator to a gain voltage divider circuit which cycles the applied voltage between two different voltage potentials tapped from the voltage divider string.

Abstract: A mobile printer having features particularly suited for use in a mobile conveyance such as an airplane. The printer stores a first data set in a memory that is accessed under control of a programmable controller. The printer then receives a second data set via a communications transceiver. Data from the first and second data sets are combined to form a composite bit mapped image which is printed by means of a thermal printhead controlled by the programmable controller.

Abstract: Method and apparatus for imaging of a subject. Radiation intensity data is transformed to a frequency domain, filtered, retransformed and then backprojected to allow an operator to examine a cross sectional image of the subject. Based upon this image, a filter function is adjusted and a second image is presented. Further adjustments can be made in the filter function to fine tune the image. The filter adjustments are all rapidly performed with the aid of a pointing device that can easily and intuitively allow the user to adjust the filter function characteristics.

Abstract: A mobile printer having features particularly suited for use in a mobile conveyance such as an airplane. The printer stores a first data set in a memory that is accessed under control of a programmable controller. The printer then receives a second data set via a communications transceiver. Data from the first and second data sets are combined to form a composite bit mapped image which is printed by means of a thermal printhead controlled by the programmable controller.The thermal printhead uses rolls of thermally sensitive paper which are supported by means of a mandrel roll. The thermal paper is positioned adjacent the print head by means of a platen roll. A biasing force is provided to bias the platen roll away from the print head when a door in the printer housing is opened to provide a space into which the free end of the roll of paper can enter.