11 results about "Calibration phantom" patented technology

An apparatus and method for calibrating a photon-counting computed tomography (PCCT) apparatus, includes performing for each offset from a rotation center, a scan of a calibration phantom placed at the offset to obtain calibration data including measured count rate data. Location parameters of the calibration phantom are estimated for each of the plurality of offsets, based on the obtained calibration data. Thickness data of the calibration phantom is determined based on the estimated location parameters. A curve is estimated, by curve fitting using the measured count rate data and the determined thickness data, indicating a relationship between the energy bin count rate and phantom thickness, for each energy bin of each pixel of the plurality of pixels. A first look-up table is generated for pixel-to-pixel count rate variation correction, and the first look-up table is applied to acquired energy bin count data to reduce ring artifacts in an image reconstructed using the acquired energy bin count data. A second look-up table is generated for both pixel-to-pixel count rate variation correction and additional count-rate non-linearity correction, using water as the calibration material, and the second look-up table is applied to reduce both ring artifacts and cupping or doming artifacts in an image reconstructed using the acquired energy bin count data.

The application discloses a skin dose calculation method based on a depth camera, comprising the following steps: obtaining the transformation relationship between the beam coordinate system of a three-dimensional perspective device and the camera coordinate system of the depth camera by calibrating a calibration phantom with a plurality of marker balls; collecting corresponding images by the depth camera and calculating the coordinates of each pixel point in the image under the beam coordinate system according to the transformation relationship; determining the beam region according to the beam angle of the ray source, combining the coordinates of each pixel point to determine the actual incident position and the incident depth of the patient, and calculating the corresponding skin dose accordingly. The application can locate the actual incident position of the patient by the depth camera, calculate the skin dose at the actual incident position, and display accurate skin dose indication.

The utility model relates to a kind of laser lamp verification mould, including mould main body, level, adjusting support leg and support leg drive assembly, cross mark area is provided on mould main body upper surface and four sides, identification metal ball is provided at the center of mould main body, level is set on mould main body upper surface, four diagonal places of mould main body lower surface are provided with screw hole, adjusting support leg includes support base and rotating column, rotating column lower end is hinged with support base, rotating column outer circumferential surface is provided with external thread, external thread and screw hole are adapted, support leg drive assembly is used to drive support leg to adjust up and down, the abrasion of this mould can be avoided when leveling operation.

The invention relates to a method for producing a calibration phantom to support diagnosis in computed tomography and an analysis method, which continuously remains inside a CT device, provides calibration in all scans by fully covering a wide spectrum of the HU scale, enables inter-device data standardisation, and has data processing methods that may be developed within this scope, thereby providing different application areas.

A calibration phantom holder for an imaging system is provided. In one example, the calibration phantom holder includes a horizontal member with a plurality of parallel slots distributed along an upper surface of the horizontal member. Each parallel slot of the plurality of parallel slots is configured to support one or more calibration phantoms. The calibration phantom holder includes a vertical member perpendicularly coupled to the horizontal member. The vertical member configured to couple to a support system of the imaging system.

This disclosure provides a method for obtaining an energy threshold, a method for decomposing a matrix material, a system, an apparatus, and a medium. The method for obtaining the energy threshold includes: acquiring imaging images of at least two preset calibration phantoms corresponding to preset energy ranges based on preset imaging parameters; wherein the preset calibration phantoms include a target matrix material, and the preset energy ranges are determined according to a preset energy threshold in the preset imaging parameters; acquiring the mass decay coefficient of the preset calibration phantoms based on the imaging images; determining the decay difference between the target matrix materials based on the mass decay coefficient; and determining the target energy threshold for imaging based on the decay difference and the preset energy threshold. This disclosure calculates the decay difference based on the actually measured mass decay coefficient of the preset calibration phantom corresponding to the target matrix material, and determines the target energy threshold based on the decay difference and the preset energy threshold used during measurement, which can assist in determining the selection of the target energy threshold for any target matrix material to be decomposed.

A phantom eye includes a curved reflectance standard having a light-receiving surface configured to be illuminated by light and one or more ocular media components positioned such that the light passes through the one or more ocular media components prior to illuminating the light-receiving surface of the curved reflectance standard. The curved reflectance standard mimics an optical property of a retina of a biological eye. The one or more ocular media components mimic an optical property of the biological eye.

This invention discloses a C-arm calibration method, apparatus, and system based on image feature extraction. The method includes: precisely placing the calibration phantom on... C The imaging area of ​​the shape-arm is exposed under the initial pose to acquire the initial image and extract the initial two-dimensional coordinates of the marker points. Combined with the known three-dimensional coordinates of the marker points, the initial projection parameters are calculated; the driving... C The telescopic arm rotates around at least one axis of its coordinate system to multiple calibration poses, records the angles and exposures, and extracts the calibration 2D coordinates. Based on the rotation angles and initial 3D coordinates, the calibration 3D coordinates under each calibration pose are determined, and then the corresponding projection parameters are calculated. Based on each calibration pose and its projection parameters, a system is established. C The precise mapping relationship between the pose of the manipulator arm and its projection parameters. This invention achieves image feature processing-based results by acquiring images of the calibrated manipulator under different poses and calculating the projection parameters. C The boom provides a precise pose-projection parameter mapping relationship through one-time rapid positioning.

A system generates a navigation space and a virtual space based on images. The virtual space includes a calibration phantom comprising a pair of protrusions or a single protrusion. The system also identifies multiple sets of coordinates in the virtual space based on the intersection of an imaging device projection with the pair or single protrusion, and determines an optimal set of coordinates in the virtual space based on a first event of the imaging device projection intersecting with the midpoint of each protrusion in the pair, or a second event of the imaging device projection intersecting with the tip of a single protrusion. In response to the first event and based on the optimal set of coordinates, the system also calibrates a first coordinate system associated with the virtual space relative to a second coordinate system associated with the navigation space.