Abstract: A method may include obtaining a feedback or a reference value of a tube voltage applied to a radiation source of a radiation device for generating radiation rays. The method may also include determining, based on the feedback or the reference value of the tube voltage, a specific value of a focusing parameter associated with a focusing device of the radiation device. The method may further include causing the focusing device to shape a focus of the radiation rays according to the determined value of the focusing parameter. The focus of the radiation rays may satisfy an operational constraint under the specific value of the focusing parameter.

Abstract: According to one embodiment, an X-ray CT apparatus includes processing circuitry. The processing circuitry is configured to acquire set tube current waveform, and specify, based on the set tube current waveform, a period of a first tube current and a period of a second tube current lower than the first tube current. The processing circuitry is further configured to determine a waveform of a grid voltage such that a first grid voltage is applied during a period corresponding to the period of the first tube current and a second grid voltage, which is higher than the first grid voltage, is applied during a period corresponding to the period of the second tube current.

Abstract: Various methods and systems are provided for x-ray tube conditioning for a computed tomography imaging method. In one embodiment, x-ray may be generated in an x-ray tube of a radiation source prior to a diagnostic scan to warmup the x-ray tube to a desired temperature for the diagnostic scan. The power delivered to the x-ray tube during warmup may be adjusted in a closed loop system based on an initial temperature of the x-ray tube and the desired temperature for the diagnostic scan. During tube warmup, by placing a blocking plate coupled to a collimator blade in a path of the x-ray beam, the x-ray beam may be blocked from exiting a collimator.

Abstract: The present disclosure relates to systems and methods for energy imaging. The method may include obtaining a reference waveform of a tube voltage of a radiation source of a scanner. The reference waveform may be formed based on a superposition of a sine wave and one or more harmonics corresponding to the sine wave. The method may include causing a high voltage generator to generate the tube voltage changing between a first voltage and a second voltage lower than the first voltage according to the reference waveform. The tube voltage may be provided to the radiation source for generating radiation rays. The method may further include causing the scanner to perform energy imaging.

Abstract: A system for compensating for a back emission current in an X-ray generator is provided. The system includes a transformer, a common, and a voltage source. The transformer is operative to provide power to an electron emitter of the X-ray generator. The common is electrically coupled to an anode of the X-ray generator. The anode is operative to receive electrons emitted by the electron emitter such that the back emission current is generated between the common and the electron emitter. The voltage source electrically couples the common to the transformer and is operative to generate an offset voltage that reduces the back emission current.

Abstract: In an X-ray CT device according to an embodiment, reconstruction circuitry reconstructs a positioning image from projection data collected based on a detection signal of transmitted X-rays in positioning imaging performed at a first tube current. Circuitry detects body parts of a subject included in the positioning image. Storage stores information pieces relating to body parts, image quality levels for each of the information pieces relating to the body parts, and an X-ray count value corresponding to each of the image quality levels in an associated manner. The circuitry selects an image quality level corresponding to a desired body part. The circuitry acquires a second tube current based on the first tube current, an X-ray count value in the positioning imaging, and an X-ray count value associated with the selected image quality level. The circuitry controls an X-ray tube to perform main imaging based on the second tube current.

Abstract: A method and a system for detecting a pantograph-catenary electric arc based on a train power supply system are provided. The method includes: boosting, by a booster transformer, a voltage of alternating current transmitted via an electric network, to generate high voltage electrical energy, where a high voltage and a great current are generated in a gap between a catenary wire and a pantograph in a discharging circuit with the high voltage electrical energy; and collecting an electric arc generated in the gap between the catenary wire and the pantograph in a case of the high voltage and the great current.

Abstract: The present disclosure may provide a micro X-ray tube with a filter tube to filter X-rays and at the same time to serve as an insulator. For this, the X-ray tube may include a filter tube between a second electrode and a gate electrode, hence separating from each other. The second electrode may have a target and the gate electrode may accelerate an electron-beam to collide with the target. The filter tube includes an alumina (Al2O3). The target is inclined to allow the X-rays to be directed toward the filter tube.

Abstract: Among other things, one or more techniques and/or systems for selectively inhibiting radiation from being generated by a radiation source are provided. A radiation source comprises an electrically conductive gate situated between a cathode and an anode. When a voltage potential is created between the gate and the cathode, a flow of electrons between the cathode and the anode is mitigated, thus inhibiting radiation from being generated by the radiation source. When the voltage potential is removed or lessened, electrons may more freely flow between the cathode and the anode to generate radiation. In some embodiments, a calibration, such as a dark calibration, may be performed while the gate mitigates the flow of electrons. Moreover, in some embodiments, an accelerating voltage applied to the radiation source may be held substantially constant when radiation is generated as well as when radiation generation is inhibited.

Abstract: In a high-voltage apparatus according to this invention, a predetermined voltage is applied to a rotating anode after waiting until the number of rotations increases to such an extent that the rotating anode is not damaged. That is, X-rays of desired intensity are already outputted from a point of time when the voltage is applied to the rotating anode. Therefore, diagnosis can be performed immediately after the voltage is applied to the rotating anode. That is, unlike the prior art, there is no need to wait until X-ray intensity becomes suitable for diagnosis after X-ray emission is started, and there is no need to irradiate the patient with unnecessary X-rays. Therefore, the patient can be inhibited from being irradiated with excessive X-rays (with an improvement made in a response from when the operator gives instructions for starting fluoroscopy until emission of X-rays suitable for diagnosis).

Abstract: An electrical circuit for alternating current generation comprising a direct current control box, a first inductor, a second inductor, a first capacitor, and dual load connections. The direct current control box can alternately provide positive direct current to the first inductor then negative direct current to the second inductor. A second end of each inductor can be electrically connected together and electrically connected to a first load connection. A common connection on the control box can be electrically connected to a second load connection. The first load connection and the second load connection can be configured to be electrically connected across a load. A first capacitor can be electrically connected between the first load connection and the second load connection and configured to be electrically connected in series or parallel parallel with the load.

Abstract: An industrial X-ray tube formed by accommodating a cathode and anode in a container having an evacuated interior, in which electrons emitted from the cathode are caused to strike the anode and X-rays are emitted from the anode. The cathode is formed from graphite. The graphite is a layered crystal obtained by layering a plurality of carbon hexagonal planes. The graphite is cut based on crystal axes of the carbon hexagonal planes. The resulting cut surface is caused to function as an electron-emitting surface. For example, directions of an a- and b-crystal axis may be set so as to be arbitrary between each of the layers of the carbon hexagonal planes, the graphite may be cut along a surface parallel to the c-axis, and the resulting cut surface may be caused to function as an electron-emitting surface. The graphite may also be cut along a surface orthogonal to the c-axis.

Abstract: Methods and systems for active resonant voltage switching are provided. One active resonant switching system includes a voltage switching system having one or more active resonant modules to provide a switching voltage output. Each of the resonant modules includes a plurality of switching devices configured to operate in open and closed states to produce first and second voltage level outputs from a voltage input. The resonant modules also include a capacitor connected to the switching devices and configured to receive a discharge energy during a resonant operating cycle when switching an output voltage from the first voltage level to the second voltage level, wherein the capacitor is further configured to restore system energy when switching from the second to first voltage level. The resonant modules further include a resonant inductor configured to transfer energy to and from the capacitor.

Abstract: The present embodiments improve the radiation monochromy of an x-ray device with a control electrode for controlling a flow of electrons generated between a cathode and an anode. A correction voltage is generated in accordance with a correction function. This correction voltage is used for correction of a voltage applied between the anode and the cathode in terms of a constant voltage, even in the period of control using the control electrode. The voltage applied between the anode and the cathode is corrected with the generated correction voltage.

Abstract: An X-ray generating apparatus controls driving of an X-ray tube. The X-ray tube includes an electron source emitting electrons due to application of a voltage, a transmission-type target generating an X-ray due to collision of electrons emitted from the electron source, and a shield member disposed between the electron source and the transmission-type target, the shield member having an opening that electrons emitted from the electron source pass through, and blocking an X-ray that scatters toward the electron source. When generating the X-ray, application of a voltage to the transmission-type target is started, and emission of electrons from the electron source is caused after passage of a predetermined period indicating a time period from starting voltage application until the transmission-type target reaches a predetermined voltage. When stopping X-ray generation, application of the voltage to the transmission-type target is stopped after stopping the emission of electrons from the electron source.

Abstract: The present invention relates to an examination apparatus and a corresponding method to realize a Spectral x-ray imaging device through inverse-geometry CT.

Abstract: In a method and x-ray device to determine the value of an x-ray tube voltage to generate at least one image of defined tissue to be examined, at least one provided parameter is used that establishes or describes the desired image quality; based on the dependency of the contrast of the defined tissue to be examined on the spectrum of the x-ray radiation or on the value of the tube voltage of the x-ray tube. The tube voltage is determined also based on a contrast-to-noise ratio that is constantly maintained under consideration of the aforementioned parameter such that the dose of x-ray radiation applied to the patient is optimally low upon setting the value of the tube voltage at the x-ray tube and the acquisition of at least one x-ray projection of the defined tissue.

Abstract: The present embodiments are directed towards the abatement of eddy currents that develop in a conductive material as a result of rapidly switching the magnitude of a magnetic flux proximate the material. For example, in one embodiment, a system having a controller is provided. The controller is configured to apply voltage pulses to a magnetic coil, the magnetic coil being operable to steer an electron beam within a housing comprising conductive material. The voltage pulses include a first pulse configured to cause the magnetic coil to switch from generating a first magnetic flux to generating a second magnetic flux, and a second pulse configured to induce a first eddy current having substantially the same directional orientation as the first magnetic flux.

Abstract: A shielded, low-noise, high-voltage power supply having a plurality of voltage multipliers, each having a toroidal transformer, and collectively producing a high DC output voltage from an AC voltage. A main conductor carries the AC voltage, and is positioned proximate each toroidal transformer of the plurality of voltage multipliers. A conductive shell is conductively connected to the main conductor, and substantially encloses the plurality of voltage multipliers and the main conductor, the conductive shell providing a return path for the AC voltage in the main conductor and providing EMI shielding of the voltage multipliers and the main conductor. Other features are provided, including an intermediate transformer for conditioning/isolating the AC voltages.

Abstract: The present invention relates to an X-ray imaging apparatus, and more particularly, to an X-ray imaging apparatus in which a condenser is charged with low battery voltage, and the charged voltage of the condenser, or the sum voltage of the output voltage of the battery serially connected to the condenser and the charged voltage of the condenser is used as X-ray generating power. The X-ray imaging apparatus according to the present invention is configured such that the battery power and the condenser power are serially connected to provide power for operating the X-ray imaging apparatus, thus generating power for operating the X-ray imaging apparatus from the low battery power, and obtaining a lightweight and less bulky X-ray imaging apparatus.

Abstract: An X-ray generating apparatus controls driving of an X-ray tube. The X-ray tube includes an electron source emitting electrons due to application of a voltage, a transmission-type target generating an X-ray due to collision of electrons emitted from the electron source, and a shield member disposed between the electron source and the transmission-type target, the shield member having an opening that electrons emitted from the electron source pass through, and blocking an X-ray that scatters toward the electron source. When generating the X-ray, application of a voltage to the transmission-type target is started, and emission of electrons from the electron source is caused after passage of a predetermined period indicating a time period from starting voltage application until the transmission-type target reaches a predetermined voltage. When stopping X-ray generation, application of the voltage to the transmission-type target is stopped after stopping the emission of electrons from the electron source.

Abstract: An X-ray tube includes a target and a cathode assembly. The cathode assembly includes a first filament configured to emit a first beam of electrons toward the target, a first gridding electrode coupled to the first filament, a second filament configured to emit a second beam of electrons toward the target, and a second gridding electrode coupled to the second filament.

Abstract: An apparatus and method for utilizing reactive power in electric power generating facilities. The primary energy source is a reactive power provided by a source of high-frequency, high-voltage electromagnetic oscillations. As a device, the Reactive Current Transformer consists of a high-voltage, high-frequency electromagnetic generator, preferably Tesla Resonant Transformer and of inductive receiving coils, electromagnetically coupled in the absence of a ferromagnetic core, adjusted in resonance with this electromagnetic generator and mounted in any required quantity, close to it. Energy, emitted by the electromagnetic generator, is being transferred to inductive coils. Reactive current induced in the inductive coils can be collected from them and converted to a standard AC voltage for further use by any convenient way, preferably with a help of additional inductive transforming windings, mounted together and electromagnetically coupled with these inductive coils.

Abstract: An apparatus and method for calibrating an x-ray tube include a computer programmed to acquire a starter voltage/current value corresponding to a width, a length, or a position of a target focal spot capable of being generated by the x-ray tube. The computer is programmed to generate an electron beam and to steer the electron beam based on the starter voltage/current value. The computer is also programmed to steer the electron beam based on a value adjusted from the starter voltage/current value. The computer is programmed to calculate a final voltage/current value that is configured to generate the width, length, or position of the target focal spot based on the starter voltage/current value and the adjusted starter voltage/current value.

Abstract: An X-ray CT apparatus has an irradiation unit, a determination unit, and a displaying unit. The irradiation unit is configured to emit an X-ray. The determination unit determines a tube current value modulation to extend to a body axis direction in a predetermined rotation angle of the irradiation unit based on an index value to show a dispersion of CT values in a required area in a reconstructed image, and a scan condition. The displaying unit displays an image of the index value and an image of the tube current value modulation on an image used for positioning and aligns the image along the body axis direction on the image used for positioning.

Abstract: In a method and x-ray device to determine the value of an x-ray tube voltage to generate at least one image of defined tissue to be examined, at least one provided parameter is used that establishes or describes the desired image quality; based on the dependency of the contrast of the defined tissue to be examined on the spectrum of the x-ray radiation or on the value of the tube voltage of the x-ray tube. The tube voltage is determined also based on a contrast-to-noise ratio that is constantly maintained under consideration of the aforementioned parameter such that the dose of x-ray radiation applied to the patient is optimally low upon setting the value of the tube voltage at the x-ray tube and the acquisition of at least one x-ray projection of the defined tissue.

Abstract: In a high-voltage apparatus according to this invention, a predetermined voltage is applied to a rotating anode after waiting until the number of rotations increases to such an extent that the rotating anode is not damaged. That is, X-rays of desired intensity are already outputted from a point of time when the voltage is applied to the rotating anode. Therefore, diagnosis can be performed immediately after the voltage is applied to the rotating anode. That is, unlike the prior art, there is no need to wait until X-ray intensity becomes suitable for diagnosis after X-ray emission is started, and there is no need to irradiate the patient with unnecessary X-rays. Therefore, the patient can be inhibited from being irradiated with excessive X-rays (with an improvement made in a response from when the operator gives instructions for starting fluoroscopy until emission of X-rays suitable for diagnosis).

Abstract: When the same subject is to be imaged consecutively plural times, a radiation imaging device is controlled so as to change an imaging time interval between respective imagings according to a set imaging region of the subject. When a chest portion of a subject is to be imaged, a control section designates an image obtained at a second imaging as an image for diagnosis, image quality correction processing is not performed at a first imaging, and an imaging time interval is greatly reduced compared to when other regions are imaged, thereby reducing motion artifacts of an energy subtraction image. When regions other than a chest region are imaged, the control section designates an image obtained at a first imaging as an image for diagnosis, performs image quality correction processing at the first imaging, and an imaging time interval is increased compared to when the chest region is imaged.

Abstract: An X-ray apparatus includes a converter into which there is integrated a control logic circuit configured to regulate the supply voltage of a high-voltage power supply source of the X-ray apparatus. To this end, the intelligent voltage-voltage, converter is placed between the power battery and the capacitor bank. This intelligent converter is capable of determining the optimum voltage to be delivered to the generator for the radiology examination to be undertaken in regulating the current of the power battery at the necessary level of current.

Abstract: An X-ray generating apparatus controls driving of an X-ray tube. The X-ray tube includes an electron source emitting electrons due to application of a voltage, a transmission-type target generating an X-ray due to collision of electrons emitted from the electron source, and a shield member disposed between the electron source and the transmission-type target, the shield member having an opening that electrons emitted from the electron source pass through, and blocking an X-ray that scatters toward the electron source. When generating the X-ray, application of a voltage to the transmission-type target is started, and emission of electrons from the electron source is caused after passage of a predetermined period indicating a time period from starting voltage application until the transmission-type target reaches a predetermined voltage. When stopping X-ray generation, application of the voltage to the transmission-type target is stopped after stopping the emission of electrons from the electron source.

Abstract: The present embodiments improve the radiation monochromy of an x-ray device with a control electrode for controlling a flow of electrons generated between a cathode and an anode. A correction voltage is generated in accordance with a correction function. This correction voltage is used for correction of a voltage applied between the anode and the cathode in terms of a constant voltage, even in the period of control using the control electrode. The voltage applied between the anode and the cathode is corrected with the generated correction voltage.

Abstract: There is provided an inverter device that can detect short-circuit of a switching element of an inverter circuit even under a load condition that a PWM driving signal is very small. The inverter device is provided with means for independently supplying a short-circuit detecting PWM driving signal to respective switching elements S1 to S4 at different timings before the inverter circuit 21 supplies a PWM driving signal for supplying power to a high voltage generating device 31, successively turning on the respective switching elements S1 to S4 with the short-circuit detecting PWM driving signal, detecting on-voltages of the switching elements S1 to S4 which are connected to the turned-on switching elements S1 to S4 in series, and detecting overcurrent or short-circuit states of the switching elements S1 to S4.

Abstract: A system is provided, which includes a rotatable gantry for receiving an object to be scanned. The system includes an x-ray source for projecting x-rays of two different energy levels towards the object and also a power supply, which energizes the x-ray source to two different voltage levels at a predetermined rate for generating x-rays at two different energy levels. The power supply in the system includes a fixed voltage source to input a voltage to a switching module with number of identical switching stages. Each stage in the switching module consists of a first switch, which charges a capacitor in a conducting state and output a first voltage, a second switch, which connects the fixed voltage source and the capacitor in series to output a second voltage in a conducting state and a diode which blocks a reverse current from the capacitor to the power supply.

Abstract: A system is provided, which includes a rotatable gantry for receiving an object to be scanned. The system includes an x-ray source for projecting x-rays of two different energy levels towards the object and also a power supply, which energizes the x-ray source to two different voltage levels at a predetermined rate for generating x-rays at two different energy levels. The power supply in the system includes a fixed voltage source to input a voltage to a switching module with number of identical switching stages. Each stage in the switching module consists of a first switch, which charges a capacitor in a conducting state and output a first voltage, a second switch, which connects the fixed voltage source and the capacitor in series to output a second voltage in a conducting state and a diode which blocks a reverse current from the capacitor to the power supply.

Abstract: A medical device can perform treatment and diagnosis without causing a sense of unease to the patient. The medical device includes a substantially ring-shaped support frame provided in such a manner that a central axis through which an isocenter passes is disposed substantially horizontally; a substantially ring-shaped moving gantry which slides relative to the support frame and which has an opening at the isocenter side thereof a radiation emitter configured to emit a beam towards the isocenter; and a protective cover which covers the radiation emitter and an inner circumferential side of the moving gantry and which moves together with the moving gantry.

Abstract: A control system for an X-ray source includes a sensor interface for receiving one or more sensor signals representative of operation of the X-ray source; a programmable controller operative in response to the one or more sensor signals and a sequence of control instructions for generating one or more control signals for controlling the X-ray source; and a control interface for supplying the one or more control signals to the X-ray source, either directly or indirectly.

Abstract: The present invention is directed to a networked scanner environment wherein each scanner is communicatable with one or more databases configured to store data associated with previously executed imaging sessions. The one or more databases may be queried by a user to determine, based on a set of user inputs, an historical evaluation of the prior imaging sessions conducted in accordance with scan parameters similar to the scan parameters of an imminent imaging session. The present invention includes a global database that is accessible by a series of remotely located imaging systems as well as includes one or more databases particular to a specific treatment facility housing one or more imaging scanners. The present invention is also applicable with a stand-alone imaging system having a database local to that particular imaging system for storing and accessing data associated with imaging sessions conducted on that particular imaging system.

Abstract: An X-ray apparatus includes a converter into which there is integrated a control logic circuit configured to regulate the supply voltage of a high-voltage power supply source of the X-ray apparatus. To this end, the intelligent voltage-voltage, converter is placed between the power battery and the capacitor bank. This intelligent converter is capable of determining the optimum voltage to be delivered to the generator for the radiology examination to be undertaken in regulating the current of the power battery at the necessary level of current.

Abstract: A system and method to improve the high voltage performance of an x-ray tube with electrostatic deflection of an electron beam focal spot. The system and method provides protection of bias circuits from high voltage transients and spit protection in x-ray tubes through the use of a high voltage transient suppression and spit protection circuit assembly coupled between the bias circuits of a high voltage generator and an x-ray tube vacuum housing of an x-ray generation system.

Abstract: A method and system is presented in radiography for optimizing image quality of an object (e.g. an anatomical region of a patient), while minimizing the radiation dose to the patient. X-ray exposure parameters, such as operating voltage (kVp), operating current (mA), focal spot size, and soft x-ray filter combination, are dynamically controlled during the x-ray exposure. During at least two different sampling intervals and at two different kVp levels, x-rays are passed through the object, and detected by sensors located between the object and the image plane. After the last sampling interval, the sensor output signals and the measured thickness of the object are used to evaluate the optimal settings for the x-ray exposure parameters. The x-ray exposure parameters are set to these optimal settings for the remainder of the exposure period.

Abstract: A method for controlling focal spot size changes of an x-ray source in an imaging system includes measuring focal spot sizes as a function of a plurality of x-ray source operating parameters, determining a calibration table or transfer function utilizing the measured focal spot sizes as a function of the plurality of x-ray tube operating parameters, and utilizing the calibration table or transfer function to control focal spot size variations during operation of the imaging system.

Abstract: A control system for an X-ray source includes a sensor interface for receiving one or more sensor signals representative of operation of the X-ray source; a programmable controller operative in response to the one or more sensor signals and a sequence of control instructions for generating one or more control signals for controlling the X-ray source; and a control interface for supplying the one or more control signals to the X-ray source, either directly or indirectly.

Abstract: An apparatus and method for an x-ray system includes an x-ray emitter having a first electrode and a second electrode. A high voltage supply is electrically connected to the first electrode. A power supply is electrically connected to the second electrode. A controller electrically connected to the high voltage supply and power supply is configured to provide a predetermined parameter to the second electrode during operation of the x-ray emitter to generate the predetermined dose rate from the x-ray emitter. During operation of the x-ray emitter, at least one operational value of the second electrode corresponding to the predetermined parameter is measured and combined with the predetermined parameter using an algorithm to obtain a modified predetermined parameter to be provided by the controller to the second electrode during a subsequent operation of the x-ray emitter.

Abstract: Systems, processes and apparatus are described through which non-destructive imaging is achieved, with equivalent or increased contrast, in comparison to conventional approaches, and that facilitate reduced dosage of X-rays delivered to the object or patient being imaged.

Abstract: A control system for an X-ray source includes a sensor interface for receiving one or more sensor signals representative of operation of the X-ray source; a programmable controller operative in response to the one or more sensor signals and a sequence of control instructions for generating one or more control signals for controlling the X-ray source; and a control interface for supplying the one or more control signals to the X-ray source, either directly or indirectly.

Abstract: An active dose radiation device and method decreases the amount of x-rays which may be generated by an x-ray tube following termination of the x-ray exposure. One component of the x-ray system is connected to the device which has a plurality of electronic cells that can be overvoltaged from a first state, where they are less conductive, to a second state, where they are highly conductive. A voltage pulse generator overvoltages a first cell in the plurality of cells at termination of an x-ray exposure. Overvoltaging the first cell causes a cascading effect which eventually overvoltages all of the cells and changes the state of the cells from the first less conductive state to the second highly conductive state. In the second highly conductive state, the cells can conduct current from at least one component of the x-ray system to ground thereby reducing x-rays generated by the x-ray tube and reducing the x-ray dosage from the imaging system after the x-ray exposure has been completed.

Abstract: A plurality of region-specific areas are set on a scanogram, and an image SD value is set for each region-specific area. A tube current calculating unit calculates a tube current value at each position on the basis of a tube current pattern in a tube current pattern storage unit, an image SD value for each region-specific area, and a CT value at each position on the scanogram in each region-specific area. A scan controller controls X-ray emission in accordance with a calculated tube current value at each position.

Abstract: The non-destructive test of a structure (10) such as an aircraft fuselage is done by placing an X-ray source (16) on one side of the structure, and placing a digital camera (24) on the other side. The microcomputer (28) analyzes the image output by the digital camera in real time. If this image is unusable, at least one setting of the source (16) is modified immediately and a new acquisition is made without wasting any time. The adjustment can then be made manually or using a slaving system. The adjustment may relate to the wave length of the X-ray beam, the dose level or the pose time if the fault concerned is related to the gray level of the image. If a directional source is being used, the defect may also have an influence on the sharpness of the image and may be caused by an alignment problem.

Abstract: A method of and a system for stabilizing High Voltage Power Supply (HVPS) DC and AC voltages in multi-energy X-ray computed tomography scanners are provided. The method comprises generating filter ratios, computing DC and AC voltages, and feeding back the computed DC and AC voltages to the commanded voltages. The filtered ratios including an air ratio and a copper ratio are modeled as nonlinear functions of the DC and AC voltages. Computing DC and AC voltages include computing an m-ratio and an n-ratio. The parameters of the nonlinear model comprise an exponent parameter and a set of polynomial coefficients. The parameters are determined by a calibration procedure, which performs scanning at different combination of DC and AC voltages. The optimal parameters are obtained through a nonlinear least square minimization, which is solved through a brute force search over the exponent parameter and a closed form solution of the polynomial coefficients.

Abstract: For providing a longer lifetime and sensing an image with less noise, there is provided an image sensing apparatus having a flat panel sensor for detecting radiations, a first power circuit for supplying an electric power to the flat panel sensor, a read-out circuit for reading out data of the flat panel sensor circuit, a second power circuit for supplying an electric power to the read-out circuit, and a control circuit for turning the first power circuit on by a first timing signal and for turning the second power circuit on by a second timing signal.