219 results about "Dose calculation" patented technology

Various embodiments of the present invention provide methods and systems for deterministic calculation of radiation doses, delivered to specified volumes within human tissues and organs, and specified areas within other organisms, by external and internal radiation sources. Embodiments of the present invention provide for creating and optimizing computational mesh structures for deterministic radiation transport methods. In general these approaches seek to both improve solution accuracy and computational efficiency. Embodiments of the present invention provide methods for planning radiation treatments using deterministic methods. The methods of the present invention may also be applied for dose calculations, dose verification, and dose reconstruction for many different forms of radiotherapy treatments, including: conventional beam therapies, intensity modulated radiation therapy (“IMRT”), proton, electron and other charged particle beam therapies, targeted radionuclide therapies, brachytherapy, stereotactic radiosurgery (“SRS”), Tomotherapy®; and other radiotherapy delivery modes. The methods may also be applied to radiation-dose calculations based on radiation sources that include linear accelerators, various delivery devices, field shaping components, such as jaws, blocks, flattening filters, and multi-leaf collimators, and to many other radiation-related problems, including radiation shielding, detector design and characterization; thermal or infrared radiation, optical tomography, photon migration, and other problems.

A general imaging scheme is proposed for applications of CBCT. The approach provides a superior CBCT image quality by effective scatter correction and noise reduction. Specifically, in its implementation of CBCT imaging for radiation therapy, the proposed approach achieves an accurate patient setup using a partially blocked CBCT with a significantly reduced radiation dose. The image quality improvement due to the proposed scatter correction and noise reduction also makes CBCT-based dose calculation a viable solution to adaptive treatment planning.

An irradiation dose calculating unit can solve a problem of a conventional irradiation dose calculating unit in that since irradiation doses from portals are empirically determined, it is likely that optimum irradiation doses are not established for a target and a critical organ. A prescription data input section is used for a physician to input prescription data designating doses to a target and a critical organ. First and second object function calculating sections each calculate predefined indices, and obtain a first object function representing the level of satisfaction for the critical organ and a second object function representing the level of satisfaction for the target and critical organ. The irradiation doses from the portals are calculated based on these object functions such that the prescription data are satisfied.

A medical accelerator system consisting of coplanar and non-coplanar beams, on line magnetic resonance anatomic and functional imaging and cone beam computed tomographic imaging for single session image guided all field simultaneous radiation therapy and radiosurgery is provided. This system enables single session simulation, field-shaping block making, treatment planning, dose calculations and treatment of tumors. The radiation exposure time to the tumor and the normal tissue is reduced to a few seconds to less than a minute. In filed intensity modulated radiation is rendered by combined divergent and pencil beam, multiple smaller fields within a larger field, selectively varying beam's energy, dose rate and beam weight. Since all the treatment fields are treated simultaneously the dose rate at the tumor site is the sum of each of the converging beam's dose rate at depth. This super-high biological dose rate impairs the lethal and sublethal damage repair.

Described is a radiation dose calculation algorithm based upon the output of a radiation dosimeter including multiple sensor devices (including one or more passive integrating radiation sensors and optionally, a MEMS accelerometers, a wireless transmitters a GPS, a thermistor, or other chemical, biological or EMF sensors). The algorithm is used to convert the sensor output into dose values used to assess the exposure of personnel to ionizing radiation. Sensor output patterns are matched to stored empirically generated sensor outputs thru weighting and optimization calculation processes to determine personnel doses. Algorithm outputs can include personal dose equivalents, radiation types, radiation energy and radiation source identification. Dose calculations can be optimized for specific applications, and matched to different sets of measured data without changing the underlining software calculation programs.

A method of calculating a dose distribution for a patient for use in a radiation therapy treatment plan. The method includes acquiring an image of a volume within the patient, defining a radiation source, and defining a reference plane oriented between the radiation source and the patient. The method also includes generating a radiation therapy treatment plan, wherein the plan includes a plurality of rays that extend between the radiation source and the patient volume, and calculating a three-dimensional dose volume for the patient volume from the plurality of rays that intersect the reference plane without first having to independently calculate a dose distribution on each of the plurality of rays. The method can also include displaying the three-dimensional dose volume.

An I.V. medication warning label designed to inform attending healthcare workers of possible medication incompatibility combinations. The label includes a flexible, main label with a front surface and a back surface. The back surface has an adhesive applied thereto which allows the main label to be attached to an I.V. bag or I.V. line. Printed on the front surface of the main label is a primary medication indicator which informs the healthcare worker of the medication contained in the I.V. line or administered through the I.V. line. Also printed on the main label is a list of compatible medications, a list of incompatible medications, a dose calculation information section, a date of administration/mixture, and a plurality of removable tags with the primary medication indicator printed thereon. The removable tags may be detached from the main label and attached to other injection ports or lines located upstream or downstream from the I.V. bag.

A radiation therapy planning apparatus is provided with; a three-dimensional data collection part collecting three-dimensional data representing a plurality of positions where a plurality of portions of a subject are positioned; a marker position measurement part measuring a motion of a marker; and a dose calculation part calculating, when the subject is irradiated with therapeutic radiation changing on the basis of the motion of the subject, the dose of the therapeutic radiation with which each of the plurality of portions is irradiated, based on the motion and the three-dimensional data. The radiation therapy planning apparatus thus constructed can calculate the dose of the therapeutic radiation with which each of the respective portions of the subject is irradiated, more accurately, and reduce the dose of radiation with which the subject is irradiated in calculating the motions of the plurality of portions of the subject.

Simulating particle beam interactions includes identifying a set of n functions F₁, F₂, . . . , F_n corresponding to a plurality of different physical aspects of a particle beam, performing simulations of each F_i using a full physics model, selecting for each F_i a distribution function f_i that models relevant behavior and reducing computation of the full physics model for each F_i by replacing F_i with a distribution function f_i. The computation reduction includes comparing a set of simulations wherein each f_i replaces its respective F_i to determine if relevant behavior is accurately modeled and selecting one of f_i or F_i for each n, for a Monte Carlo simulation based on a runtime and accuracy criteria.

A method of calculating radiation fluence and energy deposition distributions on a networked virtual computational cluster is presented. With this method, complex Monte Carlo simulations that require expansive equipment, personnel, and financial resources can be done efficiently and inexpensively by hospitals and clinics requiring radiation therapy dose calculations.

An X-ray imaging apparatus includes an estimation unit (208) that estimates a cumulative exposure dose of X-rays irradiated onto an object, a remaining exposure tolerance dose calculation unit (213) that calculates a remaining exposure tolerance dose using a difference between a tolerated maximum exposure dose and the cumulative exposure dose, an X-ray irradiation tolerance period calculation unit (206) that calculates an X-ray irradiation tolerance period using a difference between a predetermined scheduled X-ray irradiation period and an actual irradiation period of X-rays irradiated onto the object, an X-ray irradiation reference dose calculation unit (212) that calculates an X-ray irradiation reference dose per unit time that will form a basis of X-ray irradiation based on the remaining exposure tolerance dose and the X-ray irradiation tolerance period, and a control unit (211) that controls X-ray irradiation onto the object by setting an X-ray irradiation dose per unit time within the X-ray irradiation tolerance period based on the X-ray irradiation reference dose.

A treatment planning method and system for optimizing a treatment plan used to irradiate a treatment volume including a target volume, such as a tumor, is disclosed. According to the method, two dose calculation algorithms are used to develop the optimized treatment plan. A first dose calculation algorithm is used to obtain substantially complete dose calculations and a second, incremental, dose calculation algorithm is used to make more limited calculations. The incremental calculations may be performed, for example, with less precision, less accuracy or less scope (e.g., focused on a specific subvolume within the treatment volume) in order to reduce the time required to achieve an optimized plan. Each of the dose calculation algorithms may be iterated a plurality of times, and different cutoff criteria can be used to limit the number of iterations in a given pass. A treatment planning system of the invention uses software for implementing the complete and incremental dose calculation algorithms. The method and system are especially useful for IMRT and arc therapy where treatment plan optimization is particularly challenging.

An X-ray CT apparatus that transmits X-rays toward a subject on the basis of a set scan condition and reconstructs images from detected X-rays that passes through the subject, including a scan plan setting unit configured to set the scan condition, a reference dose storage unit configured to store reference dose information, including an relation between an attribute information about a plurality of kinds of subjects and reference doses to be referenced for an exposure dose, and an exposure dose calculation unit configured to calculate the exposure dose corresponding to the set scan condition in accordance with the timing of setting of the scan condition.

Apparatus and methods for error modeling and correction in one or both of (i) a partially or fully implanted or non-implanted medicant delivery mechanism (such as a pump), and (ii) implanted physiologic parameter sensor. In one exemplary embodiment, the apparatus and methods employ a training mode of operation, whereby the apparatus conducts “machine learning” to model one or more errors (e.g., unmodeled variable system errors) associated with the medicant dose calculation process, and (ii) generation of a medicant delivery operational model (based at least in part on data collected/received in the training mode), which is applied to correct or compensate for the errors during normal operation of the sensor and pump system. This enhances accuracy of medicant delivery, such as over the lifetime of an implanted pump at a single implantation site, or during multiple relocations of a transcutaneously implanted pump), and enables “personalization” of the pump to each user.

The invention discloses an offline dose verification method based on improved CBCT (cone beam computed tomography) images. The offline dose verification method includes: subjecting the CBCT images of an individual patient to scatter correction on the basis of Monte-Carlo simulation to acquire a first CBCT image; rectifying the first CBCT image with a planned CT (computed tomography) image to acquire target-region deformation field information; verifying outline information of the planned CD image according to the target-region deformation field information, transplanting the verified outline information to the CBCT images to acquire a second CBCT image; establishing HU-ED calibration curves of the CBCT images according to average HU value of a particular tissue area of the individual patient in the second CBCT image and ED value of a particular tissue area of the planned CT image; performing dose calculation and planned validation on the basis of the second CBCT image, the HU-ED calibration curves, the planned CT and standard CT-ED calibration curves. By the technical scheme, treatment time and cost of the patient can be saved, and accurate adaptive radiation therapy and individual radiation therapy are realized.

A charged particle beam writing apparatus includes a dose calculation unit to calculate, for each of a plurality of first small regions made by virtually dividing a writing region of a target object to be mesh-like regions each having a size larger than an influence radius of forward scattering of a charged particle beam, a dose of the charged particle beam shot in a first small region concerned of the plurality of first small regions, by using a dose formula which is different depending on a shot type classified by whether a shot figure formed by the charged particle beam is at an edge of a figure pattern or inside the figure pattern in the first small region concerned, and a writing unit to write, for each of the plurality of first small regions, the figure pattern with a dose calculated by the dose formula.

The invention discloses a convolution and superposition dose calculation method based on Monte Carlo photon simulation. The original analysis photon flux calculation is replaced by using Monte Carlo photon transportation on the basis of the conventional photon dose calculation model; and electron transportation is replaced by using the pre-calculated energy deposition nuclear so that time of simulation calculation can be greatly reduced in comparison with full space Monte Carlo photon-electron coupling transportation. Different calculation strategies can be used according to different calculation areas for further accelerating calculation speed; and convolution and superposition calculation is performed point by point as for the calculation points of the areas of interest, only a part of specific points are calculated as for calculation points of other areas and dose information of any point is obtained through the method of interpolation so that the calculation accuracy of the concerned areas of users can be guaranteed and calculation time can be reduced.