X-ray exposure sensor and controller
AssigneeCalifornia Institute of Technology
InventorC. Martin Berdahl
Life of this patent
Estimating the term…
Abstract
An exposure controller for x-ray equipment is provided, which comprises a portable and accurate sensor which can be placed adjacent to and directly beneath the area of interest of an x-ray plate, and which measures the amount of exposure received by that area, and turns off the x-ray equipment when the exposure for the particular area of interest on the x-ray plate reaches the value which provides an optimal x-ray plate.
Claims18
In a system wherein an x-ray tube directs x-rays at one side of an object and a photographic film is positioned at the other side of said object, and means are provided for sensing the x-rays passing through said object and film for controlling the dose of x-ray exposure, the improvement in said means comprising
- scintillation means for generating photons in response to received x-rays which have passed through said film, and for enabling received x-rays to pass therethrough, said scintillation means being positioned to cover an area of said film where optimal exposure is desired,
- voltage generating means positioned adjacent to said scintillation means for generating a voltage responsive to the photons generated and x-rays passing therethrough,
- means for integrating the voltage generated by said voltage generating means to produce an integrated voltage, and
- means responsive to said integrated voltage reaching a predetermined value for inactivating said x-ray tube.
The method of controlling the level of exposure of a film to x-rays from an x-ray tube passing through a particular region of a subject to said film comprising
- generating photons in response to x-rays passing through said region and said film,
- generating a voltage in response to said photons and to said x-rays passing through said region and said film,
- integrating said voltage to produce an integrated voltage representative of the interval of exposure of said film, and
- inactivating said x-ray tube when said integrated voltage reaches a predetermined value representative of the desired exposure level.
An improved x-ray to voltage transducer comprising
- scintillation means for generating photons in response to received x-rays while enabling said received x-rays to pass therethrough, and
- means positioned adjacent to said scintillation means for generating a voltage in response to both x-rays passing through said scintillation means and said photons.
An improved radiation to voltage transducer comprising
- a plurality of scintillation means for generating photons in response to received radiation while enabling said received radiation to pass therethrough, said plurality of scintillation means being spaced one behind the other,
- a plurality of means for generating a voltage in response to either or both x-rays and photons, each of which is positioned adjacent a different one of said plurality of scintillation means for generating a voltage in response to the photons produced by a scintillating means and the x-rays passing therethrough, and each of which can pass x-rays therethrough, and
- means for combining the voltage outputs of said plurality of means for generating a voltage, to produce a combined output.
In a system in which X-rays which are applied to one side of an object pass therethrough to be received by a film on the other side of the object, an improved radiation dosage indicator comprising:
- scintillation means for generating photons in response to received X-rays which have passed through said film, and for enabling received X-rays to pass therethrough, said scintillation means being positioned to cover an area of said film where optimal exposure is desired,
- voltage generating means positioned adjacent to said scintillation means for generating a voltage responsive to the photons generated and X-rays passing therethrough,
- means for integrating the voltage generated by said voltage generating means to produce an integrated voltage, and
- means responsive to said integrated voltage for indicating the amount of X-ray dosage received by said object.
Dependencies are inferred from the claim text.