197 results about "Silicon photomultiplier" patented technology

A radiation detector includes an array of detector pixels each including an array of detector cells. Each detector cell includes a photodiode biased in a breakdown region and digital circuitry coupled with the photodiode and configured to output a first digital value in a quiescent state and a second digital value responsive to photon detection by the photodiode. Digital triggering circuitry is configured to output a trigger signal indicative of a start of an integration time period responsive to a selected number of one or more of the detector cells tranisitioning from the first digital value to the second digital value. Readout digital circuitry accumulates a count of a number of transitions of detector cells of the array of detector cells from the first digital state to the second digital state over the integration time period.

A radiation detector includes an array of detector pixels each including an array of detector cells. Each detector cell includes a photodiode biased in a breakdown region and digital circuitry coupled with the photodiode and configured to output a first digital value in a quiescent state and a second digital value responsive to photon detection by the photodiode. Digital triggering circuitry is configured to output a trigger signal indicative of a start of an integration time period responsive to a selected number of one or more of the detector cells transitioning from the first digital value to the second digital value. Readout digital circuitry accumulates a count of a number of transitions of detector cells of the array of detector cells from the first digital state to the second digital state over the integration time period.

A scintillation block detector employs an array of optically air coupled scintillation pixels, the array being wrapped in reflector material and optically coupled to an array of silicon photomultiplier light sensors with common-cathode signal timing pickoff and individual anode signal position and energy determination. The design features afford an optimized combination of photopeak energy event sensitivity and timing, while reducing electronic circuit complexity and power requirements, and easing necessary fabrication methods. Four of these small blocks, or “miniblocks,” can be combined as optically and electrically separated quadrants of a larger single detector in order to recover detection efficiency that would otherwise be lost due to scattering between them. Events are validated for total energy by summing the contributions from the four quadrants, while the trigger is generated from either the timing signal of the quadrant with the highest energy deposition, the first timing signal derived from the four quadrant time-pickoff signals, or a statistically optimum combination of the individual quadrant event times, so as to maintain good timing for scatter events. This further reduces the number of electronic channels required per unit detector area while avoiding the timing degradation characteristic of excessively large SiPM arrays.

Dual channel silicon photomultipliers (SiPMs) can replace PMTs and APDs for use in PET and other radiation detectors. The devices are compact, have high gain, high QE and low noise. Due to their timing performance, these devices can be used in time-of-flight PET applications. By dividing the device into two separate channels, one for timing resolution and one for energy resolution, both can be optimized simultaneously.

The invention relates to a photoelectric converter, a detector and scanning equipment. The photoelectric converter comprises a silicon photomultiplier array and a light guide coupled with the silicon photomultiplier array, wherein the silicon photomultiplier array comprises i*j silicon photomultipliers spliced on a horizontal plane, and the i and the j are both integers greater than or equal to 2. The detector comprises a scintillation crystal, an electronic system, a light guide and silicon photomultipliers. The scanning equipment comprises a detection device and a frame, wherein the detection device comprises the detector, and the detector comprises the photoelectric converter. According to the photoelectric converter, the detector and the scanning equipment, a photoelectric conversion scheme of the photoelectric silicon photomultipliers is mainly employed, the silicon photomultipliers have small volumes and are closely arranged, the silicon photomultipliers in proper dimensions and in proper quantity are matched with the light guide in proper shape, a PET detector with high spatial resolution can be established, so the spatial resolution of the whole PET system can be improved, the PET detector having DOI and TOF performances is proper to establish, application to PET/MRI can be realized, and low cost is further realized.

The invention discloses a SiPM-based radiation detection systems and methods. According to the invention, techniques are disclosed for systems and methods using silicon photomultiplier (SiPM) based radiation detectors to detect radiation in an environment. A SiPM-based radiation detection system may include a number of detector assemblies, each including at least one scintillator providing light to a corresponding SiPM in response to ionizing radiation entering the scintillator. The radiation detection system may include a logic device and a number of other electronic modules to facilitate reporting, calibration, and other processes. The logic device may be adapted to process detection signals from the SiPMs to implement different types of radiation detection procedures. The logic device may also be adapted to use a communication module to report detected radiation to an indicator, a display, and/or a user interface.

An imaging system includes a first silicon photomultiplier (SiPM) comprising an array of microcells. Each microcell is an avalanche photodiode (APD) operated in a Geiger mode, a first area of the first SiPM, comprising at least one of the microcells, is electrically isolated from all other microcells, and a signal from the first area, resulting from at least one photon pulse, is used to determine a gain of the first SiPM.

A photon detector (10) includes a detector array (12) comprising single photon avalanche diode (SPAD) detectors (14) configured to break down responsive to impingement of a photon. Trigger circuitry (34) is configured to generate a trigger signal responsive to break down of a SPAD detector of the detector array. Latches (20, 22) are configured to store position coordinates of SPAD detectors of the detector array that are in break down. The latches are configured to latch responsive to a trigger signal generated by the trigger circuitry. The latches may include row latches (22) each connecting with a logical "OR" combination of SPAD detectors of a corresponding row of the detector array, and column latches (20) each connecting with a logical "OR" combination of SPAD detectors of a corresponding column of the detector array. Time to digital converter (TDC) circuitry (28) may generate a digital time stamp for the trigger signal.

Apparatuses and methods are provided that minimize the effects of dark-current pulses. For example, in one embodiment of the invention, a method is provided where a first pixel is struck (i.e., a primary pixel). Pixels struck within a fixed time frame after the primary pixel is struck are referred to as secondary pixels. After a short fixed time frame has expired, the number of primary and secondary pixels is added. If the count exceeds a threshold, the primary pixel was activated by the first (or early) photon from a true gamma event. If the threshold is not met then it is likely the primary pixel generated a dark pulse that should be ignored.

The invention relates to the field of radiation measurement and provides an on-line type energy spectrum analysis anti-coincidence measurement detector. The detector comprises a sodium iodide scintillator for recording a gamma ray, a photomultiplier for converting an optical signal of the sodium iodide scintillator into a weak pulse signal, a plastic scintillator for deducting Compton flashing of the sodium iodide scintillator, a silicon photomultiplier for converting an optical signal of the plastic scintillator into a weak pulse signal, a lead shielding body for shielding an environment radiation band alignment hole and a lead plug, and a forward amplifying plate for amplifying the weak signals. The detector can achieve complex environment, Compton flashing and serious background interference always on-line measuring, eliminate the influence of nuclear site Compton flashing on 50keV-1.5MeV middle and low energy section radionuclide analysis measurement, and, at the same time, solve the difficulty that anti-coincidence measurement is unlikely to be achieved on a nuclear site.

The invention relates to a crystal arranging method and a probe thereof. A crystal is formed by array configuration of a plurality of crystal units, each crystal unit comprises a flicker crystal block and a flicker crystal block with a processed outgoing face, a portion of the processed outgoing face of the flicker crystal block is processed in a shading mode. The crystal arranging method comprises that upper and lower adjacent crystal units are arranged in a manner that the flicker crystal block and the processed flicker crystal block are mutually interval, and left and right adjacent crystal units are arranged in a manner that a shading face and a non-shading face of the outgoing face of the processed flicker crystal block are mutually interval. The crystal is adopted by the probe, and the probe comprises a silicon photomultiplier (SPM). Multiple signal units are arranged on the SPM, the signal units correspond to the crystal units one by one, and the signal units can receive light signals which are sent by the crystal units. The probe breaks through size limitation of signal units of an existing SPM, and under the condition that sizes of the signal units of the SPM are not reduced, and resolution ratio of the probe is greatly improved.

A device for detecting light includes at least one silicon photomultiplier (SiPM) having an array of a plurality of single-photon avalanche diodes (SPADs), the array being larger in area than an incident light. The device is configured so as to at least one of activate and analyze only the SPADs upon which a specific minimum intensity of light impinges.

The present invention discloses a multiple-nuclide gamma imaging system and method and belongs to the field of medical imaging. The multiple-nuclide gamma imaging system comprises a multiple-nuclide tracer injection module, a multi-nuclide scintillation crystal detector module, a configurable circuit module and an image reconstruction and imaging module. The multiple-nuclide gamma imaging method comprises the following steps: S1, starting the imaging system, setting acquisition time of the imaging system, and injecting 11C, 13N, 15O and 18F labeled compounds into an imaging object; S2, obtaining a decay event emission gamma pulse data set by positioning a gamma detector; S3, outputting an electrical signal (scintillation pulse) by a silicon photomultiplier; S4, conducting time discrimination, energy discrimination, data acquisition and coincidence processing by a detector; and S5, displaying images in a tomographic manner by a computer. The disclosed multiple-nuclide gamma imaging system and method can obtain more comprehensive data than the prior art, comprehensively analyze multi-molecule events and related influences, reduce requirements on the total gamma photon counting, reduce irradiation risks on organisms and improve a signal-to-noise ratio of reconstructed images.

The invention discloses a SiPM (Silicon Photomultiplier)-based nuclear medical imaging plate flat panel detector, which comprises multiple detection modules and a processing circuit module, wherein each detection module comprises a scintillation crystal array and a SiPM array coupled with the scintillation crystal array, the scintillation crystal array comprises multiple scintillation crystals for detecting gamma rays and generating optical signals, and the SiPM array comprises multiple SiPMs for converting the optical signals generated through the scintillation crystal array into electric signals; and the processing circuit module receives and processes the electric signals from the SiPMs to generate output signals as a detection result, and comprises a passive processing circuit module and an active processing circuit module arranged separately, the active processing circuit module leads out the electric signals generated by the SiPM array, and the active processing circuit module receives and processes the electric signals from the passive processing circuit module and generates the output signals. the flat panel detector of the invention has the advantages of compact structure, good performance and strong stability.

A silicon photomultiplier detector cell may include a photodiode region and a readout circuit region formed on a same substrate. The photodiode region may include a first semiconductor layer exposed on a surface of the silicon photomultiplier detector cell and doped with first type impurities; a second semiconductor layer doped with second type impurities; and/or a first epitaxial layer between the first semiconductor layer and the second semiconductor layer. The first epitaxial layer may contact the first semiconductor layer and the second semiconductor layer. The first epitaxial layer may be doped with the first type impurities at a concentration lower than a concentration of the first type impurities of the first semiconductor layer.

A highly efficient PET breast imager for detecting lesions in the entire breast including those located close to the patient's chest wall. The breast imager includes a ring of imaging modules surrounding the imaged breast. Each imaging module includes a slant imaging light guide inserted between a gamma radiation sensor and a photodetector. The slant light guide permits the gamma radiation sensors to be placed in close proximity to the skin of the chest wall thereby extending the sensitive region of the imager to the base of the breast. Several types of photodetectors are proposed for use in the detector modules, with compact silicon photomultipliers as the preferred choice, due to its high compactness. The geometry of the detector heads and the arrangement of the detector ring significantly reduce dead regions thereby improving detection efficiency for lesions located close to the chest wall.

The invention discloses a PET detection module, a PET detector and a PET system. The PET detection module includes a plurality of detection units, and each detection unit includes a scintillation crystal and a silicon photoelectric multiplier tube which is in one-to-one coupling with the scintillation crystal so as to read scintillation signals of the scintillation crystal, and a part between two adjacent scintillation crystals is filled with a blocking material used for blocking rays. The PET detection module has the advantages of being high in space resolution, low in error positioning probability, and capable of improving imaging quality of the PET system and improving accuracy of disease diagnosis and the like.

A method for designing a completely passive bias compensation circuit to stabilize the gain of multiple pixel avalanche photo detector devices. The method includes determining circuitry design and component values to achieve a desired precision of gain stability. The method can be used with any temperature sensitive device with a nominally linear coefficient of voltage dependent parameter that must be stabilized. The circuitry design includes a negative temperature coefficient resistor in thermal contact with the photomultiplier device to provide a varying resistance and a second fixed resistor to form a voltage divider that can be chosen to set the desired slope and intercept for the characteristic with a specific voltage source value. The addition of a third resistor to the divider network provides a solution set for a set of SiPM devices that requires only a single stabilized voltage source value.

The invention discloses a multifunctional detector capable of simultaneously measuring alpha, beta, gamma and neutrons. A plastic scintillator sprayed with zinc sulfide (ZnS (Ag)) and scintillation crystals with gamma and neutron detection and discrimination capability such as Cs2LiLaBr6: Ce (CLLB), Cs2LiYCl6: Ce (CLYC) and Cs2LiLa (Br, Cl) 6: Ce (CLLBC) are coupled together to form a coincidencecrystal, and a silicon photomultiplier is coupled with the coincidence crystal to form the detector. Alpha, beta, gamma and neutron rays are discriminated by using a pulse shape discrimination (PSD) method, and the interference of gamma rays on alpha and beta detectors can be greatly reduced by using a digital anticoincidence technology.

The invention discloses a digital PET energy parameterization calibration method. According to the digital PET energy parameterization calibration method, each detector module is provided with corresponding energy calibration coefficients via presetting; each detector module comprises one-to-one coupled crystal strips and silicon photomultipliers. The digital PET energy parameterization calibration method comprises following steps: (1) an upper computer is used for inquiring the preset energy calibration coefficients in each detector module so as to obtain an energy calibration chart; (2) the upper computer is used for acquiring energy values for calibration of each scintillation pulse event generated by the detector modules; and (3) the upper computer is used for calibrating the energy values for calibration based on the energy calibration chart so as to obtain energy values after calibration of the scintillation pulse events. According to the digital PET energy parameterization calibration method, the upper computer is used for reading the energy calibration coefficients of the detector modules and complete energy calibration of the corresponding scintillation pulse events, no radiation source is needed, the whole energy calibration process is completed in the upper computer, efficiency is high, and accuracy is high.

The invention relates to a gain control device, a gain control system and a gain control method for a silicon photomultiplier. The gain control device is used for controlling gain of the silicon photomultiplier which is connected in series with the gain control device. The gain control device comprises a controllable voltage source and at least one voltage stabilizing diode which are connected in series, wherein the controllable voltage source comprises at least one input terminal; the voltage stabilizing diode works in a breakdown state; an equivalent temperature coefficient of the voltage stabilizing diode is the same as a temperature coefficient of the silicon photomultiplier; the gain of the silicon photomultiplier is controlled by regulating voltage on the input terminal of the controllable voltage source. A technical scheme adopted by the invention is simple, uses fewer components and parts, and can realize temperature compensation by only needing to use an analog device, so that a temperature sensor, a corresponding digital unit and a corresponding feedback system are cancelled, and the reliability of the system is increased.

The invention discloses a cerebral blood flow measuring device, a cerebral blood flow measuring system and a helmet, wherein the cerebral blood flow measuring device comprises at least one group of light source device and at least two groups of detection devices; the light source device comprises a single longitudinal mode crystal laser, an optical switch and radiation optical fibers; an output end of the single longitudinal mode crystal laser is connected to an input end of an optical switch; an output end of the optical switch is connected to the at least two radiation optical fibers so as to switch a beam of inputted laser light into at least two beams of laser light and output the at least two beams of laser light; by virtue of the radiation optical fibers, the laser light is transmitted to a to-be-measured part; each detection device comprises a single mode fiber, a collimation device and a silicon photomultiplier; by virtue of the collimation device, received laser light, which is outputted by the single mode fiber, is uniformly transmitted to a receiving window of the silicon photomultiplier; and the silicon photomultiplier is used for converting a received optical signal into an electric signal and for outputting the electric signal. The cerebral blood flow measuring device disclosed by the invention has the advantages of being high in time sampling rate, high in signal to noise ratio, small in volume, good in portability and the like.