摘要:
The invention relates to a collimator (1) for defining a beam of energetic rays (2) which is emitted from an essentially punctiform radiation source (3) and is oriented onto an object (1) to be treated. The collimator is especially used for the stereotactic conformation radiotherapy of tumors. The collimator (1) is embodied in such a way that an irregular object (4) can be scanned by rays (2, 2′) which are defined by an opening in the collimator. The invention also relates to a program for controlling the collimator. In order to define the contours (29, 29′, 29″) of the objects (4) to be irradiated in a simple but highly accurate manner, especially with a precise definition of the irradiation fields, the collimator comprises a plurality of different sized openings (5, 5′ 5″). One of the openings (5, 5′, 5″) can be selectively displaced in a polydirectional manner on a strip (6) having a spherical surface, and the central axis (7) thereof is oriented towards the radiation source (3). The other collimator openings (5′, 5″) are shielded form the rays (2). A control system (9) acts on the drives (23, 24, 25) of a drive device (8) in such a way that large openings (5, 5′) are used to scan large irradiation surfaces (26) of the object to be treated (4), and small openings (5′, 5″) are used for precise definition at the edge of the irradiation surfaces (26) of the object to be treated (4), especially in the event of irregular contours (29, 29′, 29″).
摘要:
The invention relates to a displacement-detecting element (1) comprising a measuring resistance (2), voltage source (3) and a displacement-dependent voltage pick off (4). The measuring resistance (2) is embodied in the form of a strip. The length of the resistor (6) corresponds to at least the maximal length of displacement (7) of the component to be detected. The invention also relates to a multileaf collimator (23) having such a displacement-detecting element (1). The aim of the invention is to produce a displacement-detecting element (a) for detecting the position of the leaves (22) in a multileaf collimator (23) in a precise and faultless manner. The displacement detecting element (1) is designed for detecting the displacement (7′) of the leaves (22) in a multileaf collimator (23) in the following manner: the measuring resistance (2) or the voltage pick off point (4) are connected in a rigid manner to the leaves (22) in order to detect the displacement and another functioning element (4 or 2) is arranged in a fixed manner. At least one of these functioning elements (2, 4) is disposed in an area (33, 33′, 33″) of the leaves (22), which is not exposed to main radiation (34).
摘要:
The radiation system has several radiation sources aimed toward a central point. These radiation sources are on arc element that pivots on an axis. The center can hence be irradiated from different sides. The radiation sources preferably have irregularly adjustable diaphragms. The system is suitable for irradiating any part of the human body. It is easy to manufacture and simple to used.
摘要:
The invention relates to a collimator (1) for limiting a bundle of high-energy rays (2), which is emitted by a substantially point-like radiation source (3) and directed towards a treatment object (20) and used in particular for the stereotactic conformation radiotherapy of tumors. According to the invention the collimator (1) comprises a plurality of diaphragm leaves (4, 4′) which are arranged opposite each other and which are made of a radiation-absorbing material and which, by means of drive mechanisms, can be moved into the optical path in such a way that the contours and/or exposure period of said optical path can be freely defined, the front edges (5, 5′) of the diaphragm leaves (4, 4′) being parallel to the optical path at all times. Avoiding penumbral shadows with this kind of collimator (1) is made considerably easier if the diaphragm leaves (4, 4′) consists of a rear partial element (6, 6′) which can be linearly displaced and a front partial element (7, 7′) which is hinged to same. Drive means adjust the front partial element (7, 7′) in accordance with the prevailing position of the rear partial element (6, 6′) in such a way that the front edges (5, 5′) are parallel to the optical path at all times.
摘要:
A contour collimator for radiation therapy has a plurality of diaphragm elements that are movable with respect to each other by means of drive units. The diaphragm elements of the invention are supported only on the side near the drive units for ease of movement. This allows larger contour collimators to be constructed having relatively heavy diaphragm elements while retaining relatively small motors.
摘要:
The invention relates to a collimator (1) for defining a beam of energetic rays (2) which is emitted from an essentially punctiform radiation source (3) and is oriented onto an object (1) to be treated. The collimator is especially used for the stereotactic conformation radiotherapy of tumors. The collimator (1) is embodied in such a way that an irregular object (4) can be scanned by rays (2, 2′) which are defined by an opening in the collimator. The invention also relates to a program for controlling the collimator. In order to define the contours (29, 29′, 29″) of the objects (4) to be irradiated in a simple but highly accurate manner, especially with a precise definition of the irradiation fields, the collimator comprises a plurality of different sized openings (5, 5′ 5″). One of the openings (5, 5′, 5″) can be selectively displaced in a polydirectional manner on a strip (6) having a spherical surface, and the central axis (7) thereof is oriented towards the radiation source (3). The other collimator openings (5′, 5″) are shielded form the rays (2). A control system (9) acts on the drives (23, 24, 25) of a drive device (8) in such a way that large openings (5, 5′) are used to scan large irradiation surfaces (26) of the object to be treated (4), and small openings (5′, 5″) are used for precise definition at the edge of the irradiation surfaces (26) of the object to be treated (4), especially in the event of irregular contours (29, 29′, 29″).
摘要:
A method of intensity-modulating a beam of radiation from a radiation source is provided, the method including the steps of: a) providing a collimator having a window which allows the passage of radiation from the radiation source and which defines when viewed from the radiation source a two-dimensional array of bixels, the collimator further having a plurality of independently movable radiation attenuators which are constrained to move along columns or rows of the array to block selected bixels thereof, whereby, within each column or row along which the attenuators are movable, at least one arrangement of the respective attenuator(s) results in a pair of open bixels sandwiching a blocked bixel or line of blocked bixels; b) positioning the collimator in the path of the radiation source; and c) repeatedly: positioning the radiation attenuators within the window to form at each repeat a different pattern of bixels; and irradiating the collimator, until a predetermined pattern of radiation intensities for the beam of radiation has been delivered through the collimator. A corresponding apparatus for producing an intensity-modulated beam of radiation which is operable in accordance with the above method, and a method of radiotherapy treatment performed on a human or animal body comprising subjecting the body to an intensity-modulated beam of radiation formed using the above method are also provided.
摘要:
A whole body stereotaxis apparatus comprising a base plate (2) to accommoe a patient, two side strips (4, 6) which are attached to the base plate (2) at the marginal or side edges thereof and laterally delimit the base plate (2) and to which arches (10, 12) extending over the base plate (2) can be attached, characterized in that a central strip (8) is mounted on the base plate (2) and comprises bores (22) to accommodate accessories.
摘要:
A contour collimator has a plurality of plate-shaped diaphragm elements movably arranged with respect to each other in a guiding block to form a contour diaphragm for a radiation beam emitted by a radiation source towards the collimator, and at least one drive for moving the diaphragm elements. A drive is associated with each diaphragm element with the drives of a group of diaphragm elements being substantially adjacent, and a driving transmission arranged between each drive and the associated diaphragm element.
摘要:
A circuit for the conversion of an unregulated input voltage (UE) into a regulated DC output voltage (UA) is specified, with which the input voltage (UE) can assume both a higher and a lower value than the desired output voltage (UA). In addition to a set/actual value comparator (SIV), a current simulation (SNB) is provided, which simulates the current (JL) in the storage choke (L2) during charging as capacitor voltage, a common driver circuit (TRS), designed as switched constant current source, for both semiconductor switches (V1, V2), an input voltage monitoring (ESU), which switches off the switched-mode regulator when there is too low an input voltage (UE) and an output monitoring circuit (ASU), which reduces the set value of the regulating circuit on crossing in the downward direction of a selectable threshold.