133 results about "Dosimetry radiation" patented technology

An apparatus and technique for transscleral light-mediated biostimulation of the trabecular plates of a patient's eye in a treatment for glaucoma or ocular hypertension. The apparatus includes; (i) a working end geometry for contacting the anterior surface of the sclera and cornea to insure that a laser emission reaches the trabecular meshwork from a particular location on the anterior surface of the sclera, (ii) a laser energy source providing a wavelength appropriate for absorption beneath the anterior scleral surface to the depth of the trabecular plates, and (iii) a dosimetry control system for controlling the exposure of the laser emission at the particular spatial locations. The device uses a light energy source that emits wavelengths in the near-infrared portion of the spectrum, preferably in the range of about 1.30 mum to 1.40 mum or from about 1.55 mum to 1.85 mum. The depth of absorption of such wavelength ranges will extend through most, if not all, of the thickness of the sclera (750 mum to 950 mum). In accordance with a proposed method of trabecular biostimulation, the targeted region is elevated in temperature to a range between about 40° C. to 55° C. for a period of time ranging from about 1 second to 120 seconds or more.

Described is a radiation dosimeter including multiple sensor devices (including one or more passive integrating electronic radiation sensor, a MEMS accelerometers, a wireless transmitters and, optionally, a GPS, a thermistor, or other chemical, biological or EMF sensors) and a computer program for the simultaneous detection and wireless transmission of ionizing radiation, motion and global position for use in occupational and environmental dosimetry. The described dosimeter utilizes new processes and algorithms to create a self-contained, passive, integrating dosimeter. Furthermore, disclosed embodiments provide the use of MEMS and nanotechnology manufacturing techniques to encapsulate individual ionizing radiation sensor elements within a radiation attenuating material that provides a “filtration bubble” around the sensor element, the use of multiple attenuating materials (filters) around multiple sensor elements, and the use of a software algorithm to discriminate between different types of ionizing radiation and different radiation energy.

A patient-specific optimally effective radiation dose for administration of a radiopharmaceutical to a patient for treatment of a disease may be established by basing the calculation of the appropriate therapeutic dose on factors such as the desired total body dose, the maximum tolerated dose, the typical clearance profile of the radiopharmaceutical, the patient's mass or maximum effective mass, and the patient-specific residence time of the radiopharmaceutical or an analog in the whole body of the patient. The use of the method allows for treatment of a patient with an appropriate dose which is maximally effective against the disease yet minimally toxic. The determination of a patient-specific therapeutic dose may be assisted by the use of a software program set to the particular parameters of the radiopharmaceutical.

Methods and means for measuring and adjusting the gain of a photomultiplier tube (PMT), or other photo-detector with electron multiplication gain, for the purpose of achieving accurate light measurement, such as in a luminescent radiation dosimeter reader. With a PMT illuminated by a light emitting diode or other light source, the PMT output signal is measured in two modes, signal integration and photon pulse counting. The measured PMT gain is calculated as the ratio of the integrated signal to the photon pulse count. The PMT high voltage may be adjusted to cause the measured PMT gain to correspond to an established calibration gain value, or the data from the PMT may be adjusted to compensate the deviation of the measured PMT gain from the calibration gain value. The light source may be a controllable light source that can be adjusted to provide a specific photon count rate output as measured by the PMT. This invention provides for maintaining light measurement calibration without requiring temperature stabilization or a fixed light source.

A thermoluminescence (TL) dosimetry (TLD) system comprises at least one TLD element that is controllably heated and which temperature is monitored in real time using an infrared (IR) radiometry subsystem that provides respective IR radiation inputs to a control subsystem. The control subsystem uses the inputs to effect the heating control. The TLD system further comprises a TL measuring subsystem for measuring TL emission data from each heated TLD element, the TL data used in obtaining a does curve indicative of the total radiation to which the TLD element has been exposed.

In a dosimeter for measuring levels of ionizing radiation, for example during radiotherapy, a plurality of radiation sensors, such as insulated gate field effect transistors (IGFETs), are spaced apart at predetermined intervals on a support, for example a flexible printed circuit strip, and connected to a connector which can be coupled to a reader for reading the sensors. The sensors may each be connected to a reference device, which may also be an insulated gate field effect transistor, and the absorbed radiation dose may be determined by measuring, before and after the irradiation, the difference between the threshold voltages of the individual sensors and the threshold voltage reference device. Corresponding terminals of the sensors may be connected to the connector by a single conductor, thereby reducing the number of conductors required.

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 system and method for creating a combined or mixed-energy image using both low- and high-energy CT data sets acquired using a dual-energy CT system. The low- and high-energy datasets are mixed using desired weighting factors to mimic a “single-energy” image. The low-energy dataset provides data with improved contrast enhancement, but with increased noise level. The high-energy dataset provides data with lower contrast enhancement, but with better noise properties. By combining the low- and high-energy datasets in accordance with the present method, the resulting mixed-energy images utilize the information of full dose of radiation used in the dual-energy scan. A plurality of weighting metrics can be selected, including patient size, dose partitioning, or image quality, to determine the desired weighting factors based on the weighting metrics. By selecting the proper weight factors, image noise can be reduced and/or the contrast to noise ratio can be increased in the mixed-energy image.

A system and method for treating ophthalmic target tissue, including a light source for generating a beam of light, a beam delivery system that includes a scanner for generating patterns, and a controller for controlling the light source and delivery system to create a dosimetry pattern of the light beam on the ophthalmic target tissue. One or more dosage parameters of the light beam vary within the dosimetry pattern, to create varying exposures on the target tissue. A visualization device observes lesions formed on the ophthalmic target tissue by the dosimetry pattern. The controller selects dosage parameters for the treatment beam based upon the lesions resulting from the dosimetry pattern, either automatically or in response to user input, so that a desired clinical effect is achieved by selecting the character of the lesions as determined by the dosimetry pattern lesions.

The present invention generally provides methods and apparatus for controlling ion dosage in real time during plasma processes. In one embodiment, ion dosages may be controlled using in-situ measurement of the plasma from a mass distribution sensor combined with in-situ measurement from an RF probe.

Methods and computer readable media are disclosed for ultimately developing a dosimetry plan for a treatment volume irradiated during radiation therapy with a radiation source concentrated internally within a patient or incident from an external beam. The dosimetry plan is available in near"real-time" because of the novel geometric model construction of the treatment volume which in turn allows for rapid calculations to be performed for simulated movements of particles along particle tracks therethrough. The particles are exemplary representations of alpha, beta or gamma emissions emanating from an internal radiation source during various radiotherapies, such as brachytherapy or targeted radionuclide therapy, or they are exemplary representations of high-energy photons, electrons, protons or other ionizing particles incident on the treatment volume from an external source. In a preferred embodiment, a medical image of a treatment volume irradiated during radiotherapy having a plurality of pixels of information is obtained.

In order to facilitate the display and evaluation of data acquired while irradiating a body, e.g. a patient undergoing radiation therapy, using a dosimetry system which has a plurality of sensors for disposition on, in or near the body to be irradiated and a dosimetry report comprises representations, for example drawings or photographs, of the body irradiated, along with the positions and the dose data for those specific sites where the dosimeter sensors were placed. Preferably the representation comprises actual photographs of the patient with the sensors attached taken during, before or after irradiation within the sensors attached.

An ion implantation system having a dose cup located near a final energy bend of a scanned or ribbon-like ion beam of a serial ion implanter for providing an accurate ion current measurement associated with the dose of a workpiece or wafer. The system comprises an ion implanter having an ion beam source for producing a ribbon-like ion beam. The system further comprises an AEF system configured to filter an energy of the ribbon-like ion beam by bending the beam at a final energy bend. The AEF system further comprises an AEF dose cup associated with the AEF system and configured to measure ion beam current, the cup located substantially immediately following the final energy bend. An end station downstream of the AEF system is defined by a chamber wherein a workpiece is secured in place for movement relative to the ribbon-like ion beam for implantation of ions therein. The AEF dose cup is beneficially located up stream of the end station near the final energy bend mitigating pressure variations due to outgassing from implantation operations at the workpiece. Thus, the system provides accurate ion current measurement before such gases can produce substantial quantities of neutral particles in the ion beam, generally without the need for pressure compensation. Such dosimetry measurements may also be used to affect scan velocity to ensure uniform closed loop dose control in the presence of beam current changes from the ion source and outgassing from the workpiece.

A system for delivery of high dosage of radiation to a targeted spinal area is provided. This is accomplished by a system which provides for precise immobilization and positioning of the treated spinal area during dose planning and treatment via stereotactic radiosurgery. Advantages of the system include convenience to the patient, enhanced efficacy, and reduced risk of radiotoxicity to non-target tissues.

Described are a method and apparatus for determining based on motion data when an individual wearing a dosimeter is active. Also described are a method and apparatus for determining based on motion data whether an individual was wearing a dosimeter when the dosimeter was exposed to radiation. Also described are a method and apparatus for determining based on motion data whether a dosimeter was in a particular location when the dosimeter was exposed to radiation. Also described are a method and apparatus for determining based on motion data where on the body of an individual the individual was wearing a dosimeter when the dosimeter was exposed to radiation. Also described are a method and apparatus for determining based on motion data the probability that an individual is wearing a dosimeter that is assigned to the individual.

A system for providing a simulated total dose exposure measurement during a nuclear facility training exercise by locating participants using a real time location system, modeling incremental exposure as a function of location and summing incremental exposure to produce a total dose for each of the participants. Total dose may be displayed via a wireless link to a simulated dosimiter worn by each participant. Radiation sources may also have location tags and the exposure model may be modified in real time according to the tracked location of the radiation source. In one embodiment, the locating technology comprises near field locating technology based on comparing near field signal characteristics. Alternative locating technologies may be used.

In order to facilitate the display and evaluation of data acquired while irradiating a body, e.g. a patient undergoing radiation therapy, a dosimetry system has a plurality of sensors for disposition on, in or near the body to be irradiated and connected to a sensor reading instrument which is interfaced with a display system, for example a personal computer, which is arranged to display, in use, one or more representations, for example drawings or photographs, of the body to be irradiated, along with the positions and the dose data for those specific locations where the dosimeter sensors were placed.

A radiography system is disclosed of the type having means for irradiation of an object in order to form an image of the said object or in order to detect irradiation of said object, said radiography system comprising a sensor having an exposure response function, wherein the sensor is in form of a stimulable storage phosphor plate, comprising stimulable storage phosphors, preferably having a dark-decay of more than 24 hours, wherein energy of stimulation radiation is higher than energy of emission radiation upon stimulation of said storage phosphors.

A method for tracking the movement of a particle through a geometric model so as to facilitate the development of a dosimetry plan includes providing a particle with a short mean free path length; providing a geometric model which has a boundary which separates regions of the geometric model having different densities and/or compositions; arranging a first plurality of substantially uniform volume elements having a predetermined size into the geometric model; and arranging a second plurality of substantially uniform volume elements having a predetermined size less than that of the first plurality of substantially uniform volume elements, and in overlaying relation relative to the first plurality of substantially uniform volume elements.