摘要:
A patient bed drive mechanism, under control of a processor, is capable of continuously moving a patient bed through the a TOF-PET detector array having a stationary field of view (FOV) for a distance in excess of the physical extent of an axis of the array FOV. A direct memory access (DMA) rebinner card is coupled to the detector array to receive therefrom a stream of TOF-PET coincidence event data during the extent of movement of the bed. Image projection data are generated in real time from the acquired stream of TOF-PET coincidence event data via the DMA card.
摘要:
According to a preferred embodiment, the invention provides a method for extracting internal organ motion from positron emission tomography (PET) coincidence data, the method comprising the following steps: generating a data stream of PET coincidence data using the list mode capability of a PET scanner; dividing the data stream into time frames of a given length; computing a histogram A(i, t) of an axial coincidence distribution for a set of time frames; computing the axial center of mass z(t) for each of the time frames in the set of time frames based on the histogram A(i, t); transforming z(t) into the frequency domain; determining either the frequency contribution caused by respiratory motion, given by fresp, or the frequency contribution caused by heart contractions, given by fcard and Δf, identified in the frequency spectrum |Z(f)|; and carrying out further processing of Z(f) leading to curves zresp(t) and zcard(t) with which a gating sequence is established.
摘要:
A device for improved on-line histogramming of data acquired in a Positron Emission Tomography (PET) scan. The device is a Smart DRAM (SD) PCI card, of which more than one can be used in combination within a PC-based architecture for on-line histogramming. The SD PCI card is applied as either of a Gating Buffer, a histogramming card, and a normalization buffer. The Gating Buffer card alternately stores an arriving PET data packet stream into two dedicated DRAM banks. The two DRAM banks store and retransmit the packet stream in the order of arrival for an entire physiological cycle. The histogramming SD RMW PCI cards provide a very high rate of histogramming. The extendible daisy-chain of SD RMW PCI cards supports large memory banks across potentially hundreds of SD RMW PCI cards. Under a single PC, a multiple PCI Expansion chassis is employed such that a large number of PCI cards are supported.
摘要:
A method and apparatus for on-line DOI rebinning for LSO PET/SPECT to improve spatial resolution, for use in a hybrid Positron Emission Tomography (PET)/Single Photon Emission Computed Tomography (SPECT) system running in PET-mode. Data acquisition hardware is used to feed a detector pair coincidence event stream to an on-line rebinner. Gamma centroid location measurements are made by rastering assumed transaxial and radial head positions and the corresponding rebinning maps for optimal back-projected image resolution. Optimal positions are found by collecting a 64-bit list mode file, assuming a crystal position as the centroid for each of the heads, defining a sequence for varying the assumed positions, making the rebinning look-up tables, rebinning the list mode data, histogramming and reconstructing the image, assessing the image resolution, recording the best resolution number and the associated trial position variables, repeating these on the next trial variable set.
摘要翻译:用于LSO PET / SPECT的在线DOI重组以提高空间分辨率的方法和装置,用于以PET模式运行的混合正电子发射断层扫描(PET)/单光子发射计算机断层扫描(SPECT)系统。 数据采集硬件用于将检测器对重合事件流馈送到在线重组器。 伽马重心位置测量是通过对假设的横轴和径向头部位置以及相应的重新组合图进行掠夺来实现最佳背投影图像分辨率。 通过收集64位列表模式文件,假设晶体位置为每个头的质心,定义用于改变假定位置的序列,使重新排列查找表,重新列出列表模式数据,找到最佳位置, 直方图和重建图像,评估图像分辨率,记录最佳分辨率数字和相关联的试验位置变量,在下一个试验变量集中重复这些变量。
摘要:
A method for inducing cylinder power into an optical surface which comprises the steps of providing a corneal surface to an apparatus capable of indexing the position of said target to the beam path of a laser capable of photoablating the material of said target, passing said corneal surface through the domain of said laser along at least one axis and controlling the product of the intensity of said laser with time in order to control the amount of ablation of said corneal surface along at least one axis of said corneal surface.
摘要:
An apparatus and method for weighing railroad cars coupled together and in motion is disclosed which eliminates the necessity for special scales and, in particular, can be retrofitted and used in conjunction with most existing weigh bridges regardless of the length of the weight bridge, without any modification of the physical construction thereof, and with most existing weigh mechanisms.Generally, the apparatus provides two types of weighing, summation of axle weights and full draft. In addition, combinations of each are possible. During weighing by the summation of axle weights, as each axle enters the weigh bridge, a weight measurement is made and stored in memory. Cars with up to a maximum of nine axles (this is limited by the requirement rather than the electronics) are weighed by adding the axle weights, when the last car axle has entered the weigh bridge. A printer provides a hard copy record of car weights. Full draft weights can be provided, on weigh bridges longer than cars, to provide a more accurate individual car weight. Each axle on the weigh bridge has its equivalent weight stored in memory and during a full draft weight cycle, all axles other than those of the car in full draft are subtracted from the current weight. The final weight is passed to the printer to provide a hard copy record. The axle sum or full draft weight cycles are automatically carried out by signals generated from the track switch logic. The computing unit accepts trains containing cars which may be weighed on axle sum or full draft, depending on the car axle spacing and the weigh bridge length.
摘要:
A method is provided for applying a layer (112) of material to a surface of a non-metallic substrate (116) to enhance a performance characteristic. The method includes applying glass backing (114) to the non-metallic substrate (116) and cold spraying mica or boron nitride (BN) particles (128) onto a surface of the glass backing (114). A conductive tape is also provided, which is formed with the method. The conductive tape includes a first layer of an insulation material (114′), where the first layer is formed from a backing including a fiber-based or polymer backing with resilient and flexible properties for storage in a rolled form and a layer of mica particles or boron nitride particles. The conductive tape further includes a second layer (142′) positioned over the layer of particles, and formed from an electrical conductor material.
摘要:
A method is provided for applying a layer (12) of electrical insulation material to a surface (14) of a conductor (16). One embodiment of the method involves preparing the surface (14) of the conductor (16), followed by cold spraying a plurality of mica particles (28) onto the surface (14) of the conductor (16). Another embodiment of the method involves preparing the surface (14) of the conductor (16), followed by cold spraying a plurality of boron nitride (BN) particles onto the surface (14) of the conductor (16).
摘要:
Memories, systems, and methods for refreshing are provided, such as a memory with an array of memory cells divided into sections. Memories include replacement elements having a digit line, and detecting circuitry coupled to the digit line of at least one section of the memory cell array and coupled to the digit line of the replacement element. Memories include control logic configured to selectively refresh the replacement element at an occurrence when a non-neighboring section of the memory cell array relative to the replacement element is refreshed. Other memories, systems, and methods are provided.
摘要:
A system identifies when received packets are lost at a node in a multi-node processing chain. The system processing chain may include a gantry interface module for receiving coincident event data from a PET (Positron Emission Tomography) detector array, a DMA (direct memory access) rebinner card, and a transmission line coupled between the gantry interface module and the DMA card. FPGA and FIFO elements in each processing portion receive packets that may be lost if there is insufficient FIFO capacity. Lost packets are marked, discarded, and counted. At specified intervals, set in accordance with a threshold number of packets received a lost tally data packet is generated that includes count information for lost packets. The lost tally data packet is forwarded downstream when sufficient storage capacity exists.