178 results about "Isocenter" patented technology

<heading lvl="0">Abstract of Disclosure</heading> A system and method for accurately locating and tracking the position of a target, such as a tumor or the like, within a body. In one embodiment, the system is a target locating and monitoring system usable with a radiation delivery source that delivers selected doses of radiation to a target in a body. The system includes one or more excitable markers positionable in or near the target, an external excitation source that remotely excites the markers to produce an identifiable signal, and a plurality of sensors spaced apart in a known geometry relative to each other. A computer is coupled to the sensors and configured to use the marker measurements to identify a target isocenter within the target. The computer compares the position of the target isocenter with the location of the machine isocenter. The computer also controls movement of the patient and a patient support device so the target isocenter is co-incident with the machine isocenter before and during radiation therapy.

A method of continuous real-time monitoring and positioning of multi-leaf collimators during on and off radiation exposure conditions of radiation therapy to account for target motion relative to a radiation beam is provided. A prediction algorithm estimates future positions of a target relative to the radiation source. Target geometry and orientation are determined relative to the radiation source. Target, treatment plan, and leaf width data, and temporal interpolations of radiation doses are sent to the controller. Coordinates having an origin at an isocenter of the isocentric plane establish initial aperture end positions of the leaves that is provided to the controller, where motors to position the MLC midpoint aperture ends according to the position and target information. Each aperture end intersects a single point of a convolution of the target and the isocenter of the isocentric plane. Radiation source hold-conditions are provided according to predetermined undesirable operational and/or treatment states.

Systems and methods for tracking targets in real time for radiation therapy and other applications. In one embodiment, a method includes collecting position information of a marker implanted within a patient at a site relative to the target at a time t_n, and providing an objective output indicative of the location of the target based on the position information collected at time t_n. The objective output is provided to a memory device, user interface, and/or radiation delivery machine within 1 ms to 2 seconds of the time t_n when the position information was collected. This embodiment of the method can further include providing the objective output at a periodicity of 10-200 ms during at least a portion of a treatment procedure. For example, the method can further include generating a beam of ionizing radiation and directing the beam to a machine isocenter, and continuously repeating the collecting procedure and the providing procedure every 10-200 ms while irradiating the patient with the ionizing radiation beam.

A general mathematical framework is formulated to characterize the contribution of gradient non-uniformities to diffusion tensor imaging in MRI. Based on a model expansion, the actual gradient field is approximated and employed, after elimination of geometric distortions, for predicting and correcting the errors in diffusion encoding. Prior to corrections, experiments clearly reveal marked deviations of the calculated diffusivity for fields of view generally used in diffusion experiments. These deviations are most significant with greater distance from the magnet's isocenter. For a FOV of 25 cm the resultant errors in absolute diffusivity can range from approximately −10 to +20 percent. Within the same field of view, the diffusion-encoding direction and the orientation of the calculated eigenvectors can be significantly altered if the perturbations by the gradient non-uniformities are not considered. With the proposed correction scheme most of the errors introduced by gradient non-uniformities can be removed.

A method for providing radiation therapy to target tissue in a patient provides for adjustment of the vertical position of the patient couch to account for errors introduced by the weight supported by the couch at its desired positions for treatment. The method further contemplates determining the initial location of the center of the target tissue with respect to the immobilization frame supporting the patient, to eliminate errors introduced by collateral position sensing equipment. The method is particularly suited for extended distance treatments wherein, in one embodiment, a tare is established based on the actual isocenter of the gantry and then a subsequent adjustment of couch position is made with respect to movement of the couch to position the target tissue at the virtual isocenter.

A system to monitor a geometry of a treatment apparatus, an apparatus, a trackable assembly, program product, and methods are provided. The system includes a treatment apparatus having a radiation emitter, a rotating assembly controlled by a controller, and an application computer, which provides treatment delivery instructions to the controller. The system can also include a trackable assembly connected to the rotating assembly and having a fixedly connected first trackable body which functions as a reference fixture and a pivotally connected second trackable body which provides data used to determine a rotation angle of the rotating assembly. The system also includes an apparatus to track a trackable body which has a trackable body detector to detect a position of the indicators carried by the first and the second trackable bodies and a determiner to determine and verify the location of the origin of an isocenter coordinate system and to determine rotational path data about the rotating assembly.

The invention discloses a positioning method and device, an upper computer and a radiotherapy system, and belongs to the field of radiotherapy. The positioning method comprises the steps that the positions, in an infrared coordinate system, of reference mark points arranged on a noninvasive positioning device are obtained; according to the positions of the reference mark points in the infrared coordinate system and the relative positions between reference mark points in an electronic scanning image and a designated image center point, the position of the image center point in the infrared coordinate system is determined; on the basis of the position of the image center point in the infrared coordinate system, the position of an isocenter point of radiotherapy equipment in a patient supporting device coordinate system, and the conversion relation between the infrared coordinate system and the patient supporting device coordinate system, the first offset amount between the image center point and the isocenter point in the patient supporting device coordinate system is determined; and in the patient supporting device coordinate system, the first offset amount is adjusted to the presetoffset amount by adjusting the position of a patient supporting device. The positioning method is low in cost, and a patient is not harmed.

Certain embodiments of the present invention relate to a system and method for object and isocenter alignment in an imaging system. The system includes an electromagnetic, an electromagnetic receiver, and an imaging unit for determining an isocenter of an imaging scanner based on information from the electromagnetic receiver. The imaging unit identifies the isocenter based on a plurality of electromagnetic position measurements. The imaging unit identifies a center of an object to be imaged based on information from a second electromagnetic receiver. The imaging unit repositions the object based on the isocenter. In an embodiment, the emitter is located on the object, the first receiver is located on a detector, and the second receiver is located on a tool for identifying a center of the object or a portion of the object.

The invention discloses a tumor isocenter multi-angle non-planar percutaneous puncture method belonging to a novel method that a doctor carries out tumor percutaneous puncture on a tumor patient under the guidance of CT in the technical field of medical treatment, and solving the problems of high dependence on experiences and techniques of an operator, easy generation of larger puncture errors, long occupation time of puncture, large difficulty in puncturing smaller tumors or deeper tumors in early stage, and low success rate in the tumor percutaneous puncture technology. The technical scheme is as follows: the tumor isocenter multi-angle non-planar percutaneous puncture method comprises the steps of sharing an isocenter by a center point of a semi-circular piercer and a center point of a tumor through coordinate system transfer, and driving a puncture needle for realizing multi-angle non-planar puncture through sliding of an arrow rest and rotating of the piercer. The tumor isocenter multi-angle non-planar percutaneous puncture method has the advantages that the problems of high dependence on experiences and techniques of the operator, easy generation of larger puncture errors, long occupation time of puncture, large difficulty in puncturing smaller tumors or deeper tumors in early stage, and low success rate in the tumor percutaneous puncture technology are solved, vital organs, puncture taboo organs and taboo focuses can be effectively avoided, the tumor percutaneous puncture error can be shortened to 2mm under the guidance of the CT, and the highest tumor percutaneous puncture precision at home and abroad is achieved.

The invention relates to a treatment room for a particle therapy system that has a treatment room isocenter, which can be set variably during treatment and forms an origin of a coordinate system, and a patient positioning apparatus for automatically positioning the patient with reference to the set treatment room isocenter.

An imaging device including a rotator having a hollow bore for a patient to move therein and thereout, the rotator being rotatable about a longitudinal axis, at least one linkage arm extending outwards from the rotator, and imaging apparatus mounted on the at least one linkage arm, the imaging apparatus including an imaging source that emits an imaging beam to an imaging detector aligned therewith along an imaging direction, the at least one linkage arm capable of full axial rotation about an imaging isocenter along an entire length of the patient, the isocenter lying along a longitudinal axis, and wherein the imaging apparatus is operative to rotate and to capture images of the patient along the imaging direction as the patient is positioned at an angle in a range of about 0-90° inclusive with respect to the longitudinal axis.

A gantry wheel adjustment system and method to adjust a gantry wheel of a proton treatment system, including an estimation unit to estimate a bearing adjustment value for each of the adjustable bearings based on a stiffness parameter of each adjustable bearing, the stiffness parameter being a function of a force applied at each adjustable bearing and a deflection of the gantry wheel associated with the force applied at each adjustable bearing, the bearing adjustment value corresponding to a nominal position value for each adjustable bearing to compensate for gantry wheel flexing when the gantry wheel is rotated from a first angular position to a second angular position, the adjustable bearings being configured to support the gantry wheel on the bearing surface and maintain the proton beam at the isocenter of the gantry wheel during gantry wheel rotation.

The invention concerns a C-arm x-ray device with a non-isocentric C-arm on which an x-ray source is positioned and that can be orbitally or angularly rotated, whereby the C-arm x-ray device comprises a device fashioned to horizontally adjust the C-arm (which enables an adjustment of the C-arm within the plane of the C-arm) and a device fashioned to vertically adjust the C-arm, where the horizontal adjustment device and the vertical adjustment device are fashioned such that they can automatically move the central x-ray beam of the x-ray source back into the isocenter, given an orbital or angulatory rotation of the C-arm via the horizontal and vertical adjustment device. An appertaining method is also provided.

The invention relates to a rapid dosage verifying method based on an X-ray imaging flat panel detector, and the method comprises the steps: enabling a radiotherapy device to carry out irradiation according to all irradiation field parameters of a radiotherapy plan before the radiotherapy, and enabling the X-ray imaging flat panel detector to collect two-dimensional X-ray irradiation field images at the same time; converting the two-dimensional X-ray irradiation field images into the two-dimensional plane dosage distribution of a specific equivalent water depth, carrying out the reverse calculation of a two-dimensional plane dosage of an isocenter, and achieving the dosage verification of the radiotherapy plan before radiotherapy through the comparison and evaluation of the two-dimensional plane dosage calculated by a radiotherapy plan system and an actual measured two-dimensional plane dosage. The method irons out the defects that a conventional clinic dosage verification technology consumes a large amount of time and labor and needs to turn the irradiation field angle to zero, alleviates the burden of a clinic medical physic doctor, can achieve the precise and quick verification of dosage, and is high in applicability.

The present invention is, in one embodiment, a method for determining tracking control parameters for positioning an x-ray beam of a computed tomography imaging system having a movable collimator positionable in steps and a detector array including a plurality of rows of detector elements. The method includes steps of obtaining detector samples at a series of collimator step positions while determining a position of a focal spot of the x-ray beam; determining a beam position for each detector element at each collimator step utilizing the determined focal spot positions, a nominal focal spot length, and geometric parameters of the x-ray beam, collimator, and detector array; and determining a calibration parameter utilizing information so obtained. For example, in determining a target beam position at which to maintain the x-ray beam, a detector element differential error is determined according to ratios of successive collimator step positions; and a target beam position is selected for an isocenter element in accordance with the determined element differential errors.