Abstract: Systems and methods of resetting a blocking-type photoconductive imaging detector are provided. In one embodiment, after having obtained an image, the imaging detector may be reset by applying a reversed bias potential difference and illuminating the imaging radiation detector with photoexcitation radiation. The photoexcitation radiation has a wavelength selected to excite mobile charges within the photoconductive layer and a spatial intensity profile related to the measured image for neutralizing the trapped charges in a spatially compensated manner. In another embodiment, a photoionizing beam is directed onto an x-ray light valve having a liquid crystal layer in contact with a photoconductive layer.

Abstract: A remotely activated reward dispenser. The remote dispenser delivers consumable rewards in response to a trigger signal from a remote triggering device. The reward dispenser uses a two stage delivery system to prevent unintentional release of the consumable reward. A vibration stage moves a portion of the consumable reward from a reservoir to a staging platform without crushing the consumable reward. The second stage transfers the consumable reward from the staging platform to an area accessible by the animal. A vibration damping system reduces the noise generated by the reward dispenser. An adjustable transition varies the feed rate for the consumable reward.

Abstract: A remotely activated reward dispenser. The remote dispenser delivers consumable rewards in response to a trigger signal from a remote triggering device. The reward dispenser uses a two stage delivery system to prevent unintentional release of the consumable reward. A vibration stage moves a portion of the consumable reward from a reservoir to a staging platform without crushing the consumable reward. The second stage transfers the consumable reward from the staging platform to an area accessible by the animal. A vibration damping system reduces the noise generated by the reward dispenser. An adjustable transition varies the feed rate for the consumable reward.

Abstract: Systems and methods of resetting a blocking-type photoconductive imaging detector are provided. In one embodiment, after having obtained an image, the imaging detector may be reset by applying a reversed bias potential difference and illuminating the imaging radiation detector with photoexcitation radiation. The photoexcitation radiation has a wavelength selected to excite mobile charges within the photoconductive layer and a spatial intensity profile related to the measured image for neutralizing the trapped charges in a spatially compensated manner. In another embodiment, a photoionizing beam is directed onto an x-ray light valve having a liquid crystal layer in contact with a photoconductive layer.

Abstract: The present invention provides a digital x-ray radiographic imaging system. The system is based on a photoconductive detector and an electro-optic light modulator, where the photoconductive detector layer absorbs x-rays that have passed through an object to form an exposure of the object. The absorbed x-rays create a static optical image, which is stored in the electro-optic light modulator, allowing the capture of the optical image to continue over longer time. The optical image is digitized using a scanning system and an external light source. The image is then processed and stored by a computer. After the optical image is recorded, an erasing mechanism is used to reset the system before a new exposure is made.

Abstract: The present invention provides a practical design of a megavoltage x-ray detector with both high quantum efficiency (QE) and high resolution. The x-ray detector includes an optical-fiber taper (OFT) made from a large number of optical fibers, each of which is aligned with the incident x-rays from an x-ray source hitting a top surface of the optical fiber taper. The optical-fiber taper is a matrix of optical fibers with the core material made of, e.g., silica and coated with a cladding glass or polymer such that light created within the core of each optical fiber will be guided to the bottom ends of the fiber with the ends of the fibers at the bottom being optically coupled to and optical image read-out device. Each optical fiber in the optical fiber taper is fully aligned with the incident x-ray source so that x-rays entering the top of the fiber travel directly towards the bottom of the same fiber.

Abstract: A 4-dimensional digital tomosynthesis system includes an x-ray source, an x-ray detector and a processor. The x-ray source is suitable for emitting x-ray beams to an object with a periodic motion. The periodic motion is divided into (n+1) time intervals, n being a positive integer. Each of the (n+1) time intervals is associated with a time instance ti, i=0, 1, 2, . . . , n. The x-ray detector is coupled to the x-ray source for acquiring projection radiographs of the object at each time instance ti for each scan angle based on the x-ray beams. The processor is communicatively coupled to the x-ray source and the x-ray detector for controlling the x-ray source and processing data received from the x-ray detector such that all projection radiographs acquired from all scan angles for each time instance ti are reconstructed and (n+1) sets of cross sections of the object are obtained. The cross section is either a coronal cross section or a sagittal cross section.

Abstract: The present invention provides a practical design of a megavoltage x-ray detector with both high quantum efficiency (QE) and high resolution. The x-ray detector disclosed herein has a QE that can be an order of magnitude higher than that of current flat panel systems and yet has a spatial resolution equivalent to that of current flat panel systems used for portal imaging. The x-ray detector includes a large number of micro-structured electrically conducting plates, packed together with thin spacers placed between neighboring plates with the micro-structured plates oriented to be parallel to the incident x-rays in operation. Each plate includes an electrically conductive substrate with a first planar surface, elongate electrically conductive strip electrodes separated from each other with strip spacers placed in between and sitting on an insulating layer interposed between the first planar surface of the electrically conductive substrate and the strip electrodes.

Abstract: The present invention is an indirect AMFPI wherein a phosphor such as a structured cesium iodide (CsI) is used to convert x-ray energy to optical photons or a charge, which is then detected by a two-dimensional array of either thin-film transistors (TFTs) such as an amorphous a-Se TFTs or a photodiode array. A scanning control circuit generates pulses to turn on the TFTs one row at a time, and thus the charge in the individual arrays is transferred from the TFT to one or more external charge-sensitive amplifiers. The charge-sensitive amplifiers are shared by all the pixels in the same column. The two-dimensional array can be read in real time.

Abstract: A flat panel detector for radiation imaging includes an array of transistor switches each of which is associated with a pixel electrode. A radiation transducer including a top electrode and a radiation conversion layer is disposed over the array. Inhibiting mechanisms are positioned over dead zones between adjacent pixel electrodes to inhibit the accumulation of charge in the radiation conversion layer at the dead zones when the top electrode is biased and the flat panel detector is exposed to radiation. In one embodiment, the inhibiting mechanism is constituted by islands formed of semiconductor material between the array and the radiation transducer. Each island is positioned over a dead zone between adjacent pixel electrodes and contacts a pixel electrode to allow charges accumulated on the islands to drift to the pixel electrodes.

Abstract: A digital detector for radiography and fluoroscopy is disclosed. The detector includes a large area, flat panel that easily fits into a conventional X-ray room bucky tray. The detector utilizes a layer of photoconductor (i.e. a-Se in the preferred embodiment) to detect X-rays and convert the X-ray energy to charge, and an active matrix TFT array in the form of a very large area integrated circuit, for readout of the charge. A dual gate structure is used for the TFT array wherein the top gate is formed as an extension of the pixel electrode, so as to provide high voltage protection of the TFT. An integrated pixel storage capacitor is provided for enhanced absorption of X-ray energy with low pixel voltage, low leakage current and a large charge leakage time constant. In a preferred embodiment, the integrated pixel storage capacitor is created by overlapping the pixel the pixel electrode with an adjacent gate line or a separate ground line of the active matrix readout array.