156 results about "Energy window" patented technology

A method for correcting at least one of pileup effects or charge sharing effects in multi-cell photon counting detectors includes determining a correction coefficient using a count rate of an entire spectrum and applying the determined correction to the counts recorded in an energy window of interest.

The present invention relates to the field of laser processing methods and systems, and specifically, to laser processing methods and systems for laser processing multi-material devices. Systems and methods may utilize high speed deflectors to improve processing energy window and/or improve processing speed. In some embodiments, a deflector is used for non-orthogonal scanning of beam spots. In some embodiment, a deflector is used to implement non-synchronous processing of target structures.

The invention discloses a CT imaging system and a method. The method includes: conducting common CT scanning on an object to obtain a common CT image, then determining an area-of-interest in the image, making use of a photon counting detector to perform CT scanning on the area-of-interest from multiple energy windows, and then re-establishing a high resolution image of the area-of-interest. The photon counting detector is employed to collect the photon counting projection data of multiple energy windows, so that decomposition of multiple basis functions can be carried out, the energy spectrum can have high discrimination, and the numerical stability can be good.

A scintillator crystal (26)=based gamma-ray camera system is described. The gamma-ray camera system includes a spectra processing component for (34) providing improved energy resolution over that seen in conventional gamma-ray camera systems. The spectra processing component operates to deconvolve detector response functions from observed energy spectra on a pixel by pixel basis. The pixel dependent to detector response functions are obtained by a combination of theoretical simulation, and empirical calibration. By deconvolving pixel specific detector response functions, variations in response of a gamma-ray camera system across its image plane can be accounted for. This offers significant improvements in energy resolution and many of the problems associated with conventional gamma-ray camera systems are reduced. For example, the improved energy resolution allows better rejection of photons associated with Compton scattering events occurring in a source being imaged. This is because a narrower energy window filter can be used without rejecting a significant fraction of non-Compton scattered photons. The spectra processing component can be easily implemented with different types of gamma-ray imagers, for example Anger-type cameras, and may also be retroactively fitted to existing gamma-ray camera systems.

A system for detecting clinically-relevant features of a gastrointestinal (GI) tract of a subject. The system comprises an external magnetic field generator adapted to be affixed to a patient for generating at predetermined time intervals a magnetic field with respect to the subject. The magnetic field has a predetermined polarity and flux density, thereby establishing a patient coordinate system based upon the magnetic field. The system includes a capsule adapted to be swallowed by a subject. The system further includes at least one radiation source emitting X-ray or gamma radiation and at least one radiation detector. The radiation detector is configured to detect in a first energy window collimated X-ray fluorescence radiation from the X-ray contrast agent composition excited by the emitted radiation, and to detect a second energy window Compton-backscattered radiation from the X-ray contrast agent and the wall of the GI tract produced in response to the emitted radiation. The system includes a magnetic field detector configured to generate a first output responsive to a detected polarity and detected levels of flux density during exposure to the externally generated magnetic field. A processor generates a second output based upon relative changes in the first output, the first output varying as a function of relative changes in physical location or angular orientation of the capsule associated with movement of the capsule within the GI tract. A control unit configured to selectively enable or disable X-ray or gamma ray emissions from the capsule produced by the at least one radiation source based upon the second output, such that the GI tract is selectively irradiated upon detected movement of the capsule.

Systems and methods for attenuation compensation in nuclear medicine imaging based on emission data are provided. One method includes acquiring emission data at a plurality of energy windows for a person having administered thereto a radiopharmaceutical comprising at least one radioactive isotope. The method also includes performing a preliminary reconstruction of the acquired emission data to create one or more preliminary images of a peak energy window and a scatter energy window and determining a body outline of the person from at least one of the reconstructed preliminary image of the peak energy window or of the scatter energy window. The method further includes identifying a heart contour and segmenting at least the left lung. The method additionally includes defining an attenuation map based on the body outline and segmented left lung and reconstructing an image of a region of interest of the person using an iterative joint estimation reconstruction.

The invention discloses an orthogonal frequency division multiplexing (OFDM) received frame synchronizing method for co-training sequence mutual-correlation information and is applicable to all OFDM systems adding training sequences in front of data frames. The OFDM received frame synchronizing method specifically includes 1), designing a frame structure of transmitting end; 2), performing mutual-correlation calculation and energy calculation synchronously by means of delay mutual-correlation algorithm at a receiving end, and obtaining regular measuring results; and 3) selecting energy threshold value and regular measuring threshold value of an energy window, and judging synchronous time. By accumulating a plurality of segment correlation values and uniformizing, operation load is reduced. The problems about peak platform and a plurality of high and side peak values are solved, and synchronization accuracy is increased. Channel influence is eliminated by receiving segmental mutual correlation of the sequence, and high frequency offset can be resisted. Dynamic range of receiving data is enlarged after uniformization, and selection of regular judgment time threshold value and synchronous detection can be simply and accurately realized. Meanwhile, adaptability is improved, frame synchronization in various channels can be completed accurately.

When calibrating a positron emission tomography (PET) scanner, a radioactive calibration phantom is scanned over a period of several half lives to acquire a plurality of frames of scan data. Interlaced timing windows are employed to facilitate acquiring coincidence data for a plurality of coincidence timing windows and energy windows during a single calibration scan. Coincident events are binned according to each of a plurality of selected coincidence windows, and the PET scanner is calibrated for each of the plurality of coincidence timing windows using data acquired from the single calibration scan.

An apparatus includes a computed tomography (CT) scanner (10), a reconstructor (46), a polychromatic corrector (50), a material classifier (54) and an image processor (60). The scanner provides spectral CT information. The reconstructor (46) reconstructs the data from the CT scanner (10) into a volume space. The material classifier (54) determines a material composition of locations in the volume space as a function of their location in an attenuation space. Information indicative of the material composition is presented on a display (62).

The invention provides an error rate performance optimizing method of a noncoherent energy detecting UWB receiver, comprising the following steps: the outside band noise of a received signal is filtered via a bandpass filter; the signal is processed by a square-law detector, and after the synchronism process, the SNR estimation is carried out; an energy window is optimized; and an optimized threshold is selected based on a least square fitting correction gauss approximate threshold. The error rate performance optimizing method of a noncoherent energy detecting UWB receiver enables the receiver performance to be greatly improved by the combined optimization of the judgment threshold of the receiver and an energy integral window.

The invention discloses a three-dimensional micro-Doppler gesture identification method based on a convolutional neural network and relates to the fields of man-machine interaction, wireless sensing and image processing, in particular to a method for using the convolutional neural network for identifying three-dimensional micro-Doppler gesture temporal-frequency graphs detected by a three-way radar framework. According to the method, firstly, a three-way placement system framework capable of fully collecting gesture speed information is put forward; an energy window statistic technology is used for continuously extracting effective gesture time-domain signals; by means of temporal-frequency graph synthesis, fusion and processing of three-way temporal-frequency graph information can be achieved at the same time. The convolutional neural network which is subjected to cropping and additionally provided with an SVM layer is designed, image information can be fully extracted, and the identification accuracy is high.

In Positron Emission Tomography, a time window (260) and an energy window (225) are dynamically adjusted, based on an attenuation map, count rate, clinical application, discrimination tailoring, and/or offline discrimination tailoring. Detected radiation events are filtered using the dynamically adjusted energy and time windows into scattered events, random events, and true events. The true events are input to image reconstruction, correction, and error analysis.

The invention relates to a method for correcting natural gamma ray spectral logging of a barite mud well. At present, two methods, namely a five-energy window least square method and a three-energy window spectrum stripping method or a three-energy window matrix method for unfolding spectrums and solving the content of potassium, uranium and thorium of a formation are commonly adopted at home and abroad, and the precision of measuring the potassium, the uranium and the thorium is low. The method comprises the following steps of: 1) transferring logging to a lower level, namely when gamma ray (GR) is more than 85API and the layer thickness is more than 5m, performing five-energy window measurement; 2) performing three-energy window spectrum unfolding, and solving a two-low energy window correction coefficient by using the three-energy window spectrum unfolding; 3) lifting the logging, solving a five-energy window counting rate, and correcting a two-energy window correction coefficient; 4) determining whether the total GR is higher than 85 API or not, returning to the step (2) when the total GR is higher than 85 API and using the original coefficient for five-energy window spectrum unfolding when the total GR is lower than 85 API; and 5) acquiring K, U and Th of the formation by using the five-energy window spectrum unfolding. By the method, the formation lithology can be correctly determined, and the precision of measuring the potassium, the uranium and the thorium is high.

The invention provides a method and device for acquiring an energy spectrum and a device for setting an energy window. A voltage comparator is in communication connection with a detector module and receives a flicker pulse signal sent by the detector module; a DAC (digital to analog converter) is in communication connection with the voltage comparator and transmits threshold information to the voltage comparator; the voltage comparator sends a flicker pulse signal that meets the threshold information to a counter; a control and storage unit is coupled to the counter and stores and records thecount information, and the control and storage unit is also connected to the DAC and stores and records the threshold information. The method comprises the following steps of: setting a threshold of the DAC and resetting the counter; using the counter to record the pulse number of flicker pulses whose amplitude exceeds the threshold within a T time period; setting the threshold of the DAC again, resetting the counter, and then recording the pulse number of flicker pulses whose amplitude exceeds the threshold within the T time period, and repeating the operation until the threshold is zero. Themethod and device for acquiring the energy spectrum and the device for setting the energy window can effectively reduce the cost and complexity of systems such as PET and SPET, and reduce the system's demand for computing resources and time.

The invention is a kind of time and synchronization method based on interpolation of two-value energy window in wireless communication system. The method is: (1) samples the received signal of M antennas with 2 times rate and carries on A/D conversion; (2) carries on match filter; (3) carries on interpolation to output, and acquires relative result of 2N times over-sample; (4) carries on incoherent merging to the result; (5) calculates the sum of each branch path energy in window, and compares with the threshold; if the window energy is bigger than the threshold, carries on step (7), otherwise, changes the position of window, and carries on threshold judgement again; (6) compares the energy of original window and current window, if the energy of new window is bigger than the one of original window, uses the new window to replace the original window, otherwise the energy of window maintains constant, repeats step (5) until finding the biggest energy window; (7) finds out the relative peak of the window, records the correspondent synchronous phase.

The present invention provides a method for identifying a 3-D event location of a gamma interaction for enhancing the precision of event location determination and improving the practicability of an edge-on ends-read imaging detector. The method establishes two expected photopeak relations and a mapping table for every unit in the sensor array before imaging. In real practice, two sensing values with respect to the energy of scintillation photons generated during the detection on an event are obtained by the edge-on ends-read imaging detector. Furthermore, two energy windows corresponding to each sensing value are determined according to the corresponding expected photopeak relations. If both the two sensing values fall within the corresponding energy windows respectively, the event location along the long axis of sensor array is determined according to the sensor values with respect to the mapping table mentioned above.

An embodiment of the invention provides a frequency sweeping method for a wireless communication system. The frequency sweeping method for the wireless communication system includes: acquiring candidate frequency points from a frequency sweeping pattern; converting time-domain signals of the candidate frequency points into frequency-domain signals, wherein the interval among the candidate frequency points converted into the frequency domain is larger than that of the candidate frequency points in the time domain; performing energy calculation for the signals converted into the frequency domain so as to obtain frequency-domain energy windows; and selecting the frequency points with the frequency-domain energy windows larger than a preset threshold value and outputting the frequency points as frequency sweeping results. The embodiment of the invention further provides a frequency sweeping device for the wireless communication system, and further provides a web searching method and a web searching terminal for the wireless communication system based on the frequency sweeping method and the frequency sweeping device. By the aid of the methods and the devices in the embodiment, frequency sweeping times for the candidate frequency points and frequency point switching times are decreased, frequency sweeping time is shortened, and web searching efficiency of the wireless communication system is improved.

Articles transparent to infrared radiation and resistant to impact and wear are provided. In one embodiment the article comprises a substrate and a composite coating disposed over the substrate and extending from an interface with the substrate to an external surface. The coating and the substrate are capable of transmitting infrared radiation. The composite coating comprises a first phase and a second phase, where the second phase has a higher resistance to erosive wear than the first phase. The coating comprises a compositional gradient proceeding from a first composition at the interface of the coating with the substrate to a second composition at the external surface, the first composition comprising a higher concentration of the first phase than that of the second composition. The first phase has at least one property selected from the group consisting of a) a coefficient of thermal expansion (CTE) that is within about plus or minus 3 parts per million per degree centigrade of a CTE of the substrate, and b) an index of refraction that is within a range from as high as about 0.1 plus the index of refraction of the substrate to as low as about the square root of the index of refraction of the substrate.

An automatic frequency correction (AFC) apparatus used for CDMA multipath fading channels comprises a frequency-offset evaluator, an automatic frequency correction loop filter and a carrier frequency adjuster. The present invention provides a “multipath energy window” designing method for the non-determinacy of multipath signals in mobile communication environment. Frequency-offset information can be extracted from the multipath energy window by a simple calculation and evaluated by a maximal SNR weight process. This invention also provides a step-variable accumulation adjusting method and greatly improves the response speed of the AFC apparatus as compared with a conventional loop filter, whereby supplies better AFC required for CDMA mobile terminals.

A radiation detection system includes a detector unit and at least one processor. The detector unit is configured to generate signals responsive to radiation. The at least one processor is operably coupled to the detector unit and configured to receive the signals from the detector unit. The at least one processor is configured to obtain, during an imaging process, a first count for at least one of the signals corresponding to a first intrinsic energy window, the first energy window corresponding to values higher than an intrinsic peak value; obtain a second count for the at least one of the signals corresponding to a second intrinsic energy window, the second energy window corresponding to values lower than the intrinsic peak value; and adjust a gain applied to the signals based on at least the first count and the second count.

A method and apparatus for acquiring total uniformity for a scintillation imaging apparatus are provided. A generic energy (Z) map is first obtained. The generic Zmap is then corrected for linearity by use of a dot pattern. The listmode data is used to construct an energy histogram matrix. A twin Zmap is then obtained by optimizing the lower and upper boundaries of the energy window for each pixel in relation to the average energy over the Center Field of View.

A method, apparatus and system for decomposing a substance are disclosed. The substance decomposition method comprises the following steps: collecting projection data of a calibration module at two ormore energy windows, and determining the multi-energy data corresponding to the substance decomposition realization mode of the calibration module and the designated domain according to the projection data and the substance decomposition realization mode of the designated domain; the ideal mono-energy data of calibrated model under the ideal mono-energy is obtained by the preset method. The corresponding neural network is trained according to the multi-energy data, and the trained neural network reflects the mapping relationship between the multi-energy data and the ideal single-energy data.The decomposed substance is decomposed based on the projection data of the decomposed substance in the specified energy window and the trained neural network. According to the material decomposition method provided by the embodiment of the invention, the material decomposition is carried out through an artificial neural network, and the accuracy of the material decomposition is improved.