RU108623U1 - DIGITAL X-RAY FLUOROGRAPHIC CAMERA - Google Patents

Abstract

 A digital X-ray fluorography camera containing a photorecorder including a fluorescent screen and an ultra-fast lens with a CCD array mounted in a light-proof housing protected by lead, with an input window covered by a plate of X-ray transparent and opaque material, to which a fluorescent screen adjoins, which differs in color made sealed and evacuated, a photocathode connected to the negative pole of the source is adjacent to the phosphor of the fluorescent screen 20-30 kV high voltage voltage source, the positive pole of which is connected to the anode, which is a thin layer of aluminum with a thickness of 100-150 nm sprayed onto the output phosphor, with a layer thickness of about 5 μm deposited on lead glass, and the surface of the output phosphor is optically coupled to camera lens

Description

The alleged technical solution relates to the field of medical technology, more specifically to x-ray fluorographs used for screening the diagnosis of diseases of the organs of the chest cavity.

Known X-ray fluorography camera KF-70T, developed by the Zagorsk Optical-Mechanical Plant. (Chikirdin E.G. X-ray fluorographic apparatuses. - M.: Medicine, 1970.- P. 7) [1].

X-ray fluorography camera KF-70T contains a light-tight case, protected by lead, with an entrance window closed by a plate of X-ray transparent and light-tight material, which is adjacent to a flat-shaped screen consisting of a substrate, a bonding layer and a phosphor; Inside the body there is a fast lens and a photo recorder. The photorecorder contains a tape drive mechanism and an automatic control circuit connected to it with a photo exposure meter. Fluorography is performed on a roll film of a width of 70 mm.

The main disadvantage of film cameras [1] is the unacceptably large radiation load on the patient. Currently, film fluorographs are discontinued.

Known x-ray fluorography camera, in which the photodetector uses a storage screen deposited on the surface of the drum. After exposure, the reading of the latent image is carried out using an infrared laser (Copyright certificate No. 1018623, dated 13.10.82, АВВ 6/00) [2].

The use of a photo detector with a storage screen [2] allows one to reduce the radiation load on the patient by an order of magnitude. However, this X-ray technology is extremely expensive.

In our country, photo detectors with a memory screen are not available and are not used in the practice of phthisiopulmonology.

A digital X-ray fluorography camera is also known, comprising a photographic recorder including a fluorescence screen and an ultra-fast lens with a CCD matrix, mounted in a light-tight housing protected by lead, with an entrance window covered by a plate of X-ray transparent and light-tight material, to which the fluorescent screen is adjacent ( - Edited by N.N. Blinov.- M .: Medicine, 2002.-P.192) [3]. A digital X-ray fluorography camera [3] is part of a pulmonary fluorograph, for example, Renex-Fluoro, commercially available from the domestic company Gelpik.

The average effective dose received by the patient on the camera [3], selected by us as a prototype, is 50 μSv. This dose is much lower than on camera [1], but it is still potentially dangerous for children and adolescents.

The main task of scientists and engineers leading the development of new X-ray fluorography techniques is to further reduce radiation exposure. We were guided by this task when creating a new digital X-ray fluorography camera.

This medical-technical effect (reduction of radiation load on the patient) is achieved by the fact that in a digital X-ray fluorography camera containing a photographic recorder, including a fluorescent screen and an ultra-fast lens with a CCD matrix, mounted in an opaque case, protected by lead, with the input window closed by a plate of X-ray transparent and opaque material, which adjoins the fluorescent screen, the body of the photorecorder is sealed and evacuated, fluorescent to the phosphor its screen is adjacent to the photocathode connected to the negative pole of a 20-30 kV high voltage source, the positive pole of which is connected to the anode, which is a thin, 100-150 nm thick aluminum layer sprayed onto the output phosphor with a layer thickness of about 5 microns deposited on lead glass, and the surface of the output phosphor is optically paired with the lens of the photorecorder.

Studies on patent and scientific-technical information sources have shown that the design of the proposed digital X-ray fluorography camera is unknown and does not follow explicitly from the studied prior art, i.e. meets the criteria of "novelty" and "inventive step".

Further, our proposal is accompanied by a drawing and an explanation to it (figure 1).

The digital X-ray fluorography camera consists of a photographic recorder and a photo exposure meter. A photo exposure meter is not shown in the figure.

The photorecorder is located in a lightproof sealed and evacuated housing 1, protected by lead, with an entrance window 2 closed by a plate 3 made of X-ray transparent and opaque material, for example carbon fiber, to which the fluorescent screen is adjacent. The screen has a flat shape and consists of a substrate 4, on which a phosphor 5 is deposited, for example, of gadolinium crystals. Photocathode 6 is adjacent to phosphor 5. Photocathode 6 is made from a combination of antimony and cesium (SbCs ₃ ). Photocathode 6 is connected to the negative pole (-) of the high voltage source 7 20-30 kV, the positive pole (+) of which is connected to the anode 8, which is a thin, 100-150 nm thick, layer of aluminum sprayed onto the output phosphor 9, with a thickness a layer of the order of 5 μm deposited on lead glass 10.

The output phosphor 9 is made of gadolinium grains. The surface of the output phosphor 9, which is a plane, is optically coupled to an ultra-fast lens 11, which is hermetically connected to the housing 1. At the output of the lens 11, there is a CCD matrix 12, which is connected to the signal reading and processing board 13.

When the phosphor is irradiated with 5 x-ray quanta 14, the phosphor 5 converts the invisible x-ray quanta into visible rays, which knock out the photoelectrons 15. Accelerating in the electric field, the photoelectrons 15 bombard the anode 8 and cause the output phosphor to glow 9. The rays visible by the eye are collected in the axial point S of the plane of the field diaphragm of the lens 11, located at a distance f from the plane of the phosphor 9.

The proposed design of a digital X-ray fluorography camera can be widely used in pulmonology and phthisiology, especially when examining children, as it provides a significant reduction in radiation exposure (up to 5 μSv) for a patient with good image quality.

Claims (1)

A digital X-ray fluorography camera containing a photorecorder including a fluorescent screen and an ultra-fast lens with a CCD array mounted in a light-proof housing protected by lead, with an input window covered by a plate of X-ray transparent and opaque material, to which a fluorescent screen adjoins, which differs in color made sealed and evacuated, a photocathode adjacent to the negative pole of the source is adjacent to the phosphor of the fluorescent screen 20-30 kV high voltage voltage source, the positive pole of which is connected to the anode, which is a thin layer of aluminum with a thickness of 100-150 nm sprayed onto the output phosphor, with a layer thickness of about 5 μm deposited on lead glass, the surface of the output phosphor being optically coupled to camera lens