84 results about "Bragg peak" patented technology

The invention relates generally to treatment of solid cancers. More particularly, a method and apparatus for efficient radiation dose delivery to a tumor is described. Preferably, radiation is delivered through an entry point into the tumor and Bragg peak energy is targeted to a distal or far side of the tumor from an ingress point. Delivering Bragg peak energy to the distal side of the tumor from the ingress point is repeated from multiple rotational directions. Beam intensity is proportional to radiation dose delivery efficiency. The multi-field irradiation process with energy levels targeting the far side of the tumor from each irradiation direction provides even and efficient charged particle radiation dose delivery to the tumor. Preferably, the charged particle therapy is timed to patient respiration via control of charged particle beam injection, acceleration, extraction, and/or targeting methods and apparatus.

The invention concerns a device and a process for adjusting the range of an ion beam, in particular for irradiation in tumor therapy. For this purpose, first the reference position of a target volume to be irradiated is determined. Subsequently, the range of an ion beam is configured such that said beam is adjusted to the reference position of the target volume, in such a manner that the Bragg peak, i.e. the maximal energy loss and thereby the maximal damage occurs in the region of the target volume which is to be destroyed. In the case that it has been determined that the reference position has been altered by a movement of the target volume, the ion beam is then deflected from the beam axis such that the ion beam is directed to various regions of a range modulator, in order that the ion beam experience a correspondingly adjusted energy loss in passing through the range modulator. This energy loss is adjusted to correspond to the change in position of the target volume in such a manner that the change in position is compensated for by the adjustment of the range of the ion beam, and the Bragg peak is returned to the region within the target volume.

A charged particle beam extraction system and method capable of ensuring higher safety when extraction of an ion beam is on/off-controlled during irradiation of the ion beam for treatment. The charged particle beam extraction system comprises a charged particle beam generator including a synchrotron, a range modulation wheel (RMW) for forming a Bragg peak width of a charged particle beam extracted from the charged particle beam generator, a gate signal generator for controlling start and stop of extraction of the charged particle beam from the charged particle beam generator in accordance with a rotational angle of the RMW, and an irradiation control/determination section for determining whether the start and stop of extraction of the charged particle beam is controlled at desired timing by the gate signal generator.

Treatment planning methods are provided that determine the variability of relative biological effectiveness (RBE) along a beam line and calculate, among other things, what intensity of hadron beam such as a proton or a carbon ion beam should be applied to achieve a desired biological dose at treatment site of a patient afflicted with a medical condition. Typically, three or four RBE values at three or four corresponding spacially-dispersed intervals along the beam line are calculated. In one embodiment, two RBE values for the spread-out Bragg peak (SOBP) region of the treatment site; one for the proximal section and one for the declining distal section is calculated. A third and different RBE value may be determined for the distal edge region of the SOBP. A fourth value may also be calculated for a pre-SOBP region.

The invention relates to a device and a method for demarcating and calibrating a dose monitoring detector in heavy ion beam cancer treatment. The structure of the device is characterized in that a collimator, the dose monitoring detector, a mini ridge-shaped filter, a water tank and a standard ionization chamber are arranged on a beam flux axis in sequence. The standard ionization chamber is arranged inside the water tank. The depth position of an irradiation beam mini spread-out Bragg peak in water is obtained by measuring absorbed dose of the standard ionization chamber at different depth in aqueous medium. At the depth position, the dose monitoring detector is demarcated and calibrated by the standard ionization chamber so as to obtain demarcating and calibrating factors of the measurement of the dose monitoring detector for the mini spread-out Bragg peak cancer treatment beam with a Gauss arrangement. With the demarcating and calibrating factors, the entire process of three-dimensional conformal irradiation therapy with uniform physical absorption dose or uniform biological effective dose in a tumor target volume can be conveniently controlled, the requirements of the treatment of different clinical cases in practical clinical treatment are satisfied, and the treatment efficiency of a treatment device is improved.

The invention provides a sea surface wind direction extraction method based on a ship-borne high-frequency ground wave beyond visual range radar, belongs to the field of ocean remote sensing, and solves the problems that an existing sea surface wind direction extraction method is small in detection range and has no continuity, and the system is complicated. The sea surface wind direction extraction method comprises the following specific steps: obtaining a first-order sea clutter widening spectrum in a distance door by using a single receiving array element; determining corresponding positive and negative Bragg peak values and a spatial resolution of a sea clutter incidence direction according to a first-order sea clutter space-hour distribute property; obtaining a sea surface wind direction according to the relative strength of the positive and negative Bragg peak values; applying the sea surface wind direction to a resolution unit of each sea area in the distance door and extracting the wind directions of all the sea areas in the distance door; comparing the sea surface wind directions of the resolution units of the adjacent sea areas and eliminating wind direction blurs to obtain the sea surface wind direction of the distance door; and repeating the steps until the sea surface wind directions of all the distance doors are obtained. The sea surface wind direction extraction method based on the ship-borne high-frequency ground wave beyond visual range radar is used for monitoring the sea environment.

The invention discloses a method for measuring the water depth of a shallow sea based on a double-frequency high-frequency ground wave radar. According to the method, the water depth of the shallow sea is measured by using the double-frequency high-frequency ground wave radar. Under the condition of shallow water, the water depth influences a sea surface radial flow detection result, and the position of a Bragg peak approaches a zero frequency along with the reduction of the water depth. On the basis of the influence, a new monotone function about the water depth is constructed, and the waterdepth is calculated according to the measurement result of Doppler frequency shift of the sea surface radial flow of the same position by using two working frequencies of the double-frequency high-frequency ground wave radar. The technical scheme provides a new method for detecting the water depth, the double-frequency high-frequency ground wave radar can measure the water depth of the shallow sea during sea dynamic element detection; and the water depth of shallow water with a large area can be detected; and an operation amount is low, and the method is high in accuracy and robustness.

The invention relates to a device used in 3-D conformal radiotherapy to gross tumor volume with heavy ion beams, comprising a magnet scanning system, a beam monitor system, a mini-ridge filter, a range shifter, a multi-leaf collimator and a patient body surface compensator, which are sequentially arranged on the body surface of the patient. The centers of the components and the center of the gross tumor volume are located at the beam axis. The invention overcomes the defects that the conformality is low and the scatterer impairs beam quality in current 2-D conformal radiotherapy by heavy ion beams based on a passive beam flow distribution system, and adopts 3-D conformal irradiation without the scatterer needed in current 2-D conformal radiotherapy, thus improving conformality in the therapy to the gross tumor volume with heavy ion beams. The invention can protect the health organs around the gross tumor volume to the largest extent and reduce incidence of disease at the normal organs without reducing the rate of using large quantity of Bragg peak to efficiently kill the cells in the gross tumor volume, thus improving curative effect of the heavy ion beams.

A charged particle beam irradiation system in which the energy, Bragg peak, and irradiation depth of a charged particle beam, with which a patient is to be irradiated, can be checked in real time just before actual irradiation. Just before the actual irradiation, by providing a high-speed steering magnet with 100% current, a checking beam is intentionally hit into a beam damper. By using a dosimeter and a dose measuring device in front thereof, extraction beam intensity is measured. By using a multi-layer beam monitor, a dose distribution thereof is measured. Accordingly, just before the actual irradiation, the energy, Bragg peak, and irradiation depth of the charged particle beam, with which the patient is to be irradiated, can be checked accurately and in real time. When the beam has a desired dose distribution as a result of checking, continuously, extraction control is performed.