Digirad Corporation

Hughes Aircraft Company

Nova R&d, Inc.

Frank L Augustine

Clinton LaMar Lingren

Stanley J Friesenhahn

William L Ashburn

Boris Apotovsky

Jack F Butler

F Patrick Doty

Tumay O Tumer

Steve D Gaalema

Scott B Evans

Stephen D Gaalema

F Patrick Dory

Bo Pi

A high-energy photon imaging system including an imaging head, a signal processor, a data acquisition system and an image processing computer. The imaging head includes a detector comprising a plurality of closely-packed detection modules. Each detection module comprises a plurality of detection elements mounted to a circuit carrier. The detection elements produce electrical pulses having amplitudes indicative of the magnitude of radiation absorbed by the detection elements. The circuit carrier includes channels for conditioning and processing the signals generated by corresponding detection elements and for preparing the processed signals for further processing by a signal processor. Each conditioning and processing channel stores the amplitudes of the detection element electrical pulses exceeding a predetermined threshold. The detection modules employ a fall-through circuit which automatically finds only those detection elements that have a stored pulse amplitude exceeding the threshold. The fall-through circuit searches for the next detection element and associated channel having a valid event. The signal processor performs diagnostics, gain normalization, and response efficiency normalization functions. The data acquisition system controls the acquisition and processing of data received from the conditioning and processing channels, produces image data based upon the data in a format that is compatible with existing imaging cameras, and transmits the data to the image processing computer. The image processing computer formulates images based upon the processed signals and displays the formulated images on a display device.

Semiconductor gamma-ray camera and medical imaging system

A high-energy photon imaging system including an imaging head, a signal processor, a data acquisition system and an image processing computer. The imaging head includes a detector including a plurality of closely-packed detection modules. Each detection module includes a plurality of detection elements mounted to a circuit carrier. The detection elements produce electrical pulses having amplitudes indicative of the magnitude of radiation absorbed by the detection elements. The circuit carrier includes channels for conditioning and processing the signals generated by corresponding detection elements and for preparing the processed signals for further processing by a signal processor. Each conditioning and processing channel stores the amplitudes of the detection element electrical pulses exceeding a predetermined threshold. The detection modules employ a fall-through circuit which automatically finds only those detection elements that have a stored pulse amplitude exceeding the threshold. The fall-through circuit searches for the next detection element and associated channel having a valid event. The signal processor performs diagnostics, gain normalization, and response efficiency normalization functions. The data acquisition system controls the acquisition and processing of data received from the conditioning and processing channels, produces image data based upon the data in a format that is compatible with existing imaging cameras, and transmits the data to the image processing computer. The image processing computer formulates images based upon the processed signals and displays the formulated images on a display device.

A high-energy photon imaging system including an imaging head, a signal processor, a data acquisition system and an image processing computer. The imaging head includes a detector including a plurality of closely-packed detection modules. Each detection module includes a plurality of detection elements mounted to a circuit carrier. The detection elements produce electrical pulses having amplitudes indicative of the magnitude of radiation absorbed by the detection elements.

Semiconductor gamma- ray camera and medical imaging system

A multi-channel readout chip is provided in which each channel has an analog section and a digital section. Each channel of the readout chip employs low noise charge amplifiers with self trigger and calibration capabilities to provide timing information with better than 20 nanosecond precision. The trigger threshold can be adjusted to provide energy discrimination. The chip has a sparse readout function in which only the channels which have received signals greater than a preselected threshold value are readout, thus providing fast data acquisition capabilities.

Front end data readout chip

A focal plane array having an interconnect bump that has high thermal resistivity, and which may be used to interconnect the detector and readout of the array. The detector and readout each have separate heat sinks with separate temperature controls. The readout may thus be operated at a higher temperature than the detector. A high thermal resistance interconnect bump is employed to limit heat leakage from the readout to the detector to an acceptable level, and to enable a thermal gradient to be maintained simultaneously with a net savings in refrigerator power. The heat sink for the detector is made in such a way as to not obscure the active area of the detector, that is, it is annular in shape so as to surround the active area of the detector. The interconnect bump comprises a thermally insulating pedestal comprising a material such as polyimide, for example, with an over-the-edge metallization employed as an electrical contact. The pedestal employs perforating vias in order to increase the thermal resistance. Disposed on top of the pedestal is an indium bump which mates with a corresponding bump on the detector. A similar interconnect having a polyimide pedestal may also be provided on the detector to provide for even greater thermal resistance. The high thermal resistivity of the interconnect allows the detector and readout to operate at distinct optimal temperatures.

Thermally isolated focal plane readout

An infrared detector assembly is disclosed which includes a photosensitive layer (111) and a first planar contact structure (113) conductively coupled to the photosensitive layer for collecting charge carriers generated by radiation incident on the photosensitive layer. The detector assembly further includes a second planar contact structure (119) substantially coextensive with and separated from the first planar contact structure. A dielectric layer (115) separates the first and second planar contact structures. The first and second planar contact structures and the dielectric structure form a feedback capacitor which is integral with the detector assembly and which provides feedback capacitance for an externally provided amplifier.

Infrared detector with integral feedback capacitance

An infrared detector has its sensor chip assembly (10,12,14) cooled to a relatively low temperature required for its operation, whereas a preamplifier (56) required to be positioned close to the sensor chip assembly and which generates considerably more heat than does the sensor chip assembly, is thermally isolated from the sensor chip assembly and its support (16) and is cooled to a higher temperature to thereby significantly reduce the power dissipated to the coldest refrigerator stage (90).

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Encinitas, CA, United States of America

Frank L Augustine