RU105553U1 - X-RAY RADIATION RECEIVER FOR X-RAY DIAGNOSTIC APPARATUS - Google Patents

Abstract

 1. An X-ray receiver for X-ray diagnostic apparatus, having: (a) a light-tight housing, one of the walls of which is X-ray transparent; (b) an X-ray optical converter sequentially attached to this wall, an additional light- and X-ray-tight partition with through holes, on which, from the side facing the X-ray optical converter, hoods, a residual X-ray filter in the form of washers made of X-ray translucent material, which are rigidly fixed after behind the hoods in the through holes of the specified additional partition, the lens unit, each of which contains at least measures e two sequentially mounted lenses for focusing a part of the light flux corresponding to this lens, and a photodetector containing optoelectronic converters located after the lenses with partially overlapping fields of view and decoupled electrical outputs for connecting to fragment video signals; (c) an electronic unit for analog-to-digital conversion of fragmentary video signals and their preparation for further processing, which is connected by a multicore cable to the electrical outputs of the optoelectronic converters of the photodetector; and (d) external with respect to the opaque PC case, which is connected to the output of the indicated electronic unit and equipped with a display, recording means and other processing of diagnostic information, characterized in that the opaque case is equipped with a pocket, which is limited to at least X-ray

Description

Technical field

The utility model relates to the design of x-ray receivers, which are used mainly in the composition of x-ray diagnostic devices:

for angiographic studies using radiopaque substances,

to track the position of diagnostic or surgical instruments inserted into the tubular organs (in particular, blood vessels, trachea and bronchi, esophagus, etc.),

for multiple radiography of internal organs (lungs, heart, stomach, etc.),

for tapeless radiography in traumatology and

for filmless fluorography in mass surveys of the population.

In addition, such receivers can be used in X-ray machines for flaw detection of technical objects and customs control of passenger baggage and piece cargo.

State of the art

A typical structure of X-ray receivers based on an X-ray optical converter and at least two analog optoelectronic converters (in particular, TV cameras), which are rigidly fixed on a common basis so that their optical inputs are turned towards the specified Converter, the field of view is partially overlapped, and the total field of view covers the transducer area, which is now well known (see WO 98/11722).

In such receivers, the electrical outputs of all TV cameras are connected through an ADC to an external multichannel geometric distortion corrector, which synthesizes integral video output signals from fragmentary video signals. They have the greater resolution, the more TV cameras are used in the receiver, and practically do not contain distortions due to the inevitable differences in the geometric shape and size of the fields of view of individual TV cameras and also the inevitable errors in the installation of these cameras.

Years of experience in the production and use of such receivers have shown that:

in comparison with conventional fluorography, the radiation load on the patient’s body during a single examination is reduced, as a rule, by 20 or more times,

holistic output video signals can be received with a frequency of at least 25 frames per second, which is enough for angiographic studies,

the protection of medical personnel from x-ray radiation is facilitated, because displays for displaying images based on integral video output signals can be located at a safe distance from x-ray equipment,

these video signals are conveniently recorded and stored on digital computer-readable media for maintaining medical records and multiple viewing, and

digital video recordings can be converted into images on an x-ray film using the marketed “Device for printing multi-format images on a photosensitive film” (RU 22249 U1).

However, the same practical experience has shown that the quality of images based on integral output video signals is affected by optical, x-ray and electromagnetic interference.

Optical interference is caused by illumination of TV cameras from external light sources, stray light fluxes between TV cameras and an X-ray optical converter and adjacent TV cameras, and distortion of light fluxes in the optical channels of TV cameras.

X-ray interference is caused by exposure to TV-cameras not converted to visible light x-ray radiation, the power of which in the best cases is not less than 30% (but can reach 70%) of the original value.

Electromagnetic interference is caused by external random electromagnetic pulses and / or the interaction of electromagnetic fields generated around individual conductors in the transmission circuits of analog video signals from the electrical outputs of the TV cameras to the inputs of the geometric distortion corrector.

Some of these shortcomings were eliminated or, at least, significantly weakened by the improvement of the design and wiring diagrams of X-ray receivers. So, according to US 6,002,743:

placement of the main parts of the receiver in a case made of X-ray transparent but impervious to visible light material excluded the illumination of optoelectronic converters (in particular, TV cameras) from external light sources, and

the installation of a single plate of X-ray opaque translucent lead glass between the X-ray optical converter and the optical inputs of the TV cameras weakened the residual x-ray radiation.

The specialist understands that such a plate protects the TV camera from residual x-ray radiation more effectively, the greater its thickness.

However, this same plate easily passes stray light fluxes between all TV cameras and an X-ray optical converter and between adjacent TV cameras. This leads to additional distortion of the light flux in the optical channels of the TV cameras.

Indeed, the brightness of the part of the x-ray flux that has passed through the patient or other obstacle is not uniform in itself and, most importantly, differs significantly from the brightness of the rest of the specified flux. Therefore, fragments of the visible image on the X-ray optical converter have different brightnesses, and the most striking fragments generate intense Lambert radiation of light in wide solid angles. The corresponding luminous fluxes freely propagate in random directions in the lead glass plate and only partially fall on the optical inputs of the TV cameras, which are located exactly opposite the bright fragments mentioned. Other parts of these light fluxes cause parasitic illumination of neighboring TV cameras and, being repeatedly reflected from the lenses of the TV camera lenses and propagating inside the specified plate or passing through it, they get:

to the optical inputs of arbitrary TV cameras of the receiver, creating in each diagnostic session a random set of optical noise, and

to the relatively dark areas of the X-ray transducer, creating a random flare commensurate with the brightness of these areas.

These undesirable effects are especially noticeable if the angle of incidence of light rays from the X-ray optical converter on the surface of the lenses of the lenses of the respective TV cameras exceeds the angle of total internal reflection in lead glass. Moreover, in such cases, secondary reflection leads to polarization of light.

From US 6,370,225 a more advanced X-ray detector is known having:

(a) a lightproof casing, one of whose walls is radiolucent, and

(b) sequentially fixed to this wall:

x-ray optical converter

polarizing filter,

a residual x-ray filter in the form of a lead glass plate,

a unit containing at least two lenses, and

a photodetector containing at least two optoelectronic converters (in particular, in the form of TV cameras) with decoupled electrical outputs for connection to a processing system for fragmented video signals and their "stitching" into a single output video signal.

In addition, the known receiver is characterized in that:

a lead glass plate on the side that faces the lenses is divided by dull perpendicularly intersecting grooves into sections, the number of which is equal to the number of optoelectronic converters in the photodetector,

these grooves have a depth of about 0.25 to 0.35 times the thickness of the lead glass plate and are filled with opaque material, and

each lens has one input lens that is adjacent to the surface of the lead glass plate, three intermediate lenses separated by air gaps and one output lens that is adjacent to the surface of the photodetector.

Unfortunately, in an X-ray receiver according to US 6,370,225, the task of improving the quality of the output image is solved in parts and is not efficient enough, and the reliability is noticeably reduced. Really:

the polarization filter only weakens the polarized component of the light reflected from the lead glass, but does not affect the rest of the light flux,

multi-lens optical systems of lenses in which the lenses are separated by air gaps generate irregular reflections of practically non-polarized light onto the X-ray optical converter, and

darkened grooves weaken, but do not exclude parasitic illumination of neighboring optoelectronic converters due to the free propagation of light in an uncut part of a lead glass plate.

Therefore, holistic video signals usually distort the diagnostic picture. In addition, these grooves reduce to an unacceptable level not only the mechanical strength of the fragile lead glass plate, but also the reliability of the receiver as a whole.

The most advanced X-ray detector for X-ray diagnostic apparatuses is known from RU 2284089. It has:

(a) a lightproof casing, one of whose walls is radiolucent,

(b) sequentially fixed to this wall:

x-ray optical converter

additional light- and X-ray-tight partition with through holes, on which lens hoods are installed on the side facing the X-ray optical converter,

a residual X-ray filter in the form of washers made of X-ray translucent material that are rigidly fixed after the blends in the through holes of the specified additional partition,

a lens unit, each of which contains at least two sequentially mounted lenses for focusing a portion of the light flux corresponding to this lens,

a photodetector containing optoelectronic converters located after the lenses with partially overlapping fields of view and decoupled electrical outputs for connection to the processing means of fragmentary video signals,

(c) an electronic unit external to the lightproof housing for analog-to-digital conversion of fragmentary video signals, correction of geometric distortions and “stitching” of corrected fragmentary video signals into integral digital video signals, which is connected by a multicore cable to the electrical outputs of the photoelectric photodetector converters, and

(d) also a personal computer external to the lightproof casing (hereinafter referred to as a PC), which is equipped with a display for displaying images on the basis of integral digital video signals, recording them on suitable digital media and other processing of diagnostic information, which is connected to the output of the indicated electronic unit.

The length “A” of each lens hood and the distance “D” from the front along the x-rays of the surface of the specified x-ray transducer to the plane of the front along the ends of the lenses are related by the ratio A / D = (0.50 ... 0.95), the choice of which was it was experimentally justified as described in RU 2284089. It was further noted there that the electrical outputs of the optoelectronic converters are in the form of connectors that are connected to a power source and to the said external electric cable through the mating connectors of a flexible multicore cable ktronnomu unit.

The use of an additional light and X-ray barrier, a blend with the specified A / D ratio and a residual X-ray filter in the form of these washers that are rigidly fixed in the through holes of the partition,

firstly, it drastically reduced the parasitic illumination of neighboring optoelectronic converters, because the lead glass washers are optically isolated from each other in the specified partition, and the light reflected from the details of the optical channels to the surface of the X-ray optical converter and vice versa, mostly returns through the hoods to the original channels, and,

secondly, it increased the operational reliability of the receiver, because the X-ray load on the optoelectronic converters is limited only by a small part of the X-ray radiation not converted to light, which can pass through the washers of the specified filter, and the possibility of purely mechanical destruction of this filter is practically excluded.

However, connecting an external electronic unit with built-in ADCs, a geometric distortion corrector, and means of “stitching” the corrected fragmentary video signals into integral digital video signals to a photodetector requires significant hardware costs. Indeed, each core of a multicore cable, which is designed to transmit a separate analog fragmentary video signal, has a coaxial design and contains a central conductor, an insulation layer and its own metal braid. Depending on the design of the tripods of the X-ray diagnostic complex, which is equipped with a well-known X-ray detector, the length of the expensive and time-consuming to manufacture stranded cable connecting the electrical outputs of the optoelectronic converters with an external electronic unit can be from 3 to 6 meters.

Naturally, with such dimensions of a multicore cable, even an external metal sheath common to all conductors does not exclude the influence of X-ray devices and other external sources of electromagnetic interference on analog fragmentary video signals sensitive to them and, as a result, on the quality of cross-linked digital video signals. Summary of utility model essence

The utility model is based on the task of improving the relationship between the optoelectronic converters of the photodetector and a personal computer to create such an X-ray receiver that would significantly reduce hardware costs and the effect of electromagnetic interference on the quality of “crosslinked” digital video signals.

The problem is solved in that in the x-ray receiver for x-ray diagnostic apparatus, having:

(a) a lightproof casing, one of the walls of which is radiolucent;

(b) an X-ray optical converter sequentially attached to this wall, an additional light-tight and X-ray-tight partition with through holes, on which, from the side facing the X-ray optical converter, hoods, a residual X-ray filter in the form of washers made of X-ray translucent material, which are rigidly fixed after behind the lens hoods in the through holes of the specified additional partition, the lens unit, each of which contains at least measures e two sequentially mounted lenses for focusing a part of the light flux corresponding to this lens, and a photodetector containing optoelectronic converters located after the lenses with partially overlapping fields of view and decoupled electrical outputs for connection to fragment video processing tools;

(c) an electronic unit for analog-to-digital conversion of fragmentary video signals and their preparation for further processing, which is connected by a multicore cable to the electrical outputs of the optoelectronic converters of the photodetector; and

(d) external to the opaque PC case, which is connected to the output of the indicated electronic unit and equipped with a display, recording means and other processing of diagnostic information;

according to inventive concept

the light-tight casing is provided with a pocket, which is limited by at least an X-ray-tight wall, the indicated electronic unit is located in the specified pocket, and the PC is equipped with software tools for correcting geometric distortions and “stitching” the corrected fragmentary video signals into integral digital video signals and is connected to the indicated electronic unit via a digital interface.

This significantly reduces hardware costs and improves the quality of "stitched" digital video signals. Indeed, to connect the photodetector to the electronic unit located inside the lightproof enclosure, it is enough to have a short multicore cable, which is significantly less susceptible to electromagnetic interference, and digital fragmentary video signals transmitted via a digital interface are noticeably less sensitive to electromagnetic interference.

The next difference is that the digital interface is selected from the group consisting of USB, Ethernet and CameraLink. These interfaces are publicly available on the market.

Brief Description of the Drawings

Further, the essence of the utility model is illustrated by a detailed description of an improved X-ray detector with reference to the accompanying drawings, which are shown in:

figure 1 - the receiver of x-ray radiation in the context of a plane including the geometric axis of one of the vertical rows of lenses and optoelectronic converters;

figure 2 - wiring diagram of the connection of optoelectronic converters with an electronic unit and a PC (with conditionally removed rear end and one side walls of the receiver body).

The best options for translating a utility model

The proposed x-ray receiver in the simplest form of hardware implementation has (see figure 1):

(a) a lightproof casing 1, one of the end walls 2 of which is made of X-ray transparent material (for example, getinaks or carbon fiber) and the other walls can be all-metal or have a shielding metal coating;

(b) sequentially attached to the specified end wall 2:

an x-ray optical converter 3 made on the basis of salts of rare-earth elements (for example, gadolinium oxysulfide) or cesium iodide and adjacent to the x-ray transparent end wall 2 of the housing 1,

preferably interchangeable hoods 4, which are installed in the housing 1 so that the "fields of view" of the optoelectronic converters mentioned below partially overlap, and the length "A" of which is selected taking into account the distance "D" from the front of the x-ray surface of the transducer 3 to the front plane along the light path of the ends of the lenses mentioned below according to the ratio A / D = (0.50-0.95), and preferably (0.50-0.90);

an additional light- and X-ray-tight partition 5, which is rigidly fixed in the housing 1, serves as a support for the blends 4 and other parts of the optical channels indicated below and has through holes covered by washers 6 of X-ray translucent translucent material such as lead glass, which together serve as the main filter of the residual X-ray radiation

lenses 7, the number and location of which corresponds to the number and location of the following optoelectronic converters and each of which has at least two lenses 8 separated by an air gap for focusing image parts on optoelectronic converters and, as a rule, three (input, intermediate and output) apertures 9 to limit the luminous flux,

a photodetector in the form of a set of optoelectronic converters 10, each of which is mounted on its own support in the alignment device 11 for mounting on the optical axis of the corresponding lens 7 (these converters can be in the form of TV cameras, charge-coupled devices, matrices based on complementary MOS structures and other functionally similar elements with partially overlapping fields of view and decoupled electrical outputs);

(c) an electronic unit 12 for analog-to-digital conversion (hereinafter ADC) of fragmentary video signals and their preparation for further processing, which is connected via multi-core cable 13 through connectors 14 to the electrical outputs of the optoelectronic converters 10 and located inside a pocket limited by at least an X-ray-proof wall 15 inside opaque housing 1 (see figure 2); and

(d) a personal computer external to the opaque case 1 (hereinafter referred to as PC) 16 (see again FIG. 1), which is connected via a digital interface, for example, a USB cable 17 to the output of the electronic unit 12 and equipped with a display and devices not shown recording and other processing of diagnostic information. In this PC 16, software tools for correcting geometric distortions and “stitching” the corrected fragmentary video signals into integral digital video signals are installed.

The specialist will understand that the optoelectronic converters 10 and PC 16 are connected to suitable power sources, which are not conventionally shown in the drawings. Similarly, the grounding of the multi-core cable 13 is not conventionally shown.

The partition 5 and the X-ray-proof wall 15 usually consist of two especially not shown plates, namely: an absorber of residual X-ray radiation (in particular, lead) and a support made of a strong rigid material such as duralumin, steel, or reinforced polymer.

The side walls of the housing 1, the hood 4 on the inside and the diaphragm 9 on both sides usually have a black matte finish 18, and the surfaces of the washers 6 (i.e. the main X-ray filter) and lenses 8 usually have antireflection coatings 19.

The described x-ray detector operates as follows.

When assembling or during maintenance, the optoelectronic converters 10 using quotation devices 11 (see figure 1) are installed in the output planes of the lenses 7 so that the centers of the photosensitive surfaces of the transducers 10 correspond to the foci of the lenses 7 located opposite certain parts of the surface of the X-ray optical converter 3 To facilitate adjustment, known calibration test objects (spatial worlds) can be used, as is, for example, indicated in WO 98/11722.

An aligned receiver is installed in the device for x-ray diagnostics (or flaw detection or inspection) so that the object of study can be in the gap between the output of the x-ray emitter and the x-ray transparent wall 2 of the opaque case 1. Then, each time the emitter is turned on, the x-ray stream will act on the x-ray optical converter 3, which serves as the Lambertian light source and generates a luminous flux differentiated by brightness due to interaction with object of diagnosis (or flaw detection, or inspection).

Blends 4 divide this stream into separate light beams, which through the washers 6 from the lead X-ray filtering residual radiation and lenses 7 fall onto the photosensitive surfaces of the optoelectronic converters 10. They generate analog electrical signals that correspond to partially overlapping image fragments formed on the x-ray optical converter 3 These fragmentary analog signals through connectors 14 and a flexible multicore cable 13 enter the electronic unit 12, otorrhea converts them to digital form within the housing 1. This partition wall 5 and the wall 15 rentgenonepronitsaemaya short reliably protect multicore cable 13 and the electronic control unit 12 from the x-ray and electromagnetic interference.

Fragmented digital video signals are then transmitted through a digital interface 17 to a PC 16, which corrects geometric distortions and “stitches” the corrected fragments into integral digital video signals for subsequent demonstration of images on a monitor and / or for recording on suitable digital information carriers.

Some additional features of the proposed receiver are as follows. The light and X-ray barrier 5 almost completely absorbs that part of the residual X-ray radiation that does not fall onto the lead glass washers 6 and completely eliminates the light flows between the said washers 6. The lens hoods 4 sharply reduce the parasitic illumination of adjacent channels by the light reflected from the lenses 7 and / or optoelectronic converters 10 to the x-ray optical converter 3 and vice versa. The diaphragms 9 further suppress random optical interference (especially in the form of light reflected from the surface of the optoelectronic converters 10). The same purpose (but with reference to any light interference) are matte black coatings 18 of the side walls of the housing 1, blend 4 on the inside and diaphragms 9 on both sides. And finally, the antireflection coatings 19 almost by an order of magnitude reduce the reflectivity of the surfaces of the washers 6 and lenses 8.

Industrial applicability

The X-ray receiver can be manufactured in various configurations on an accessible modern element base, including TV cameras, CCDs, photodiode or CMOS matrices, etc. optoelectronic converters and arbitrary digital interfaces, and is widely used to equip mainly medical X-ray diagnostic devices.

Claims (2)

1. An X-ray receiver for X-ray diagnostic apparatus, having: (a) a light-tight housing, one of the walls of which is X-ray transparent; (b) an X-ray optical converter sequentially attached to this wall, an additional light-tight and X-ray-tight partition with through holes, on which, from the side facing the X-ray optical converter, hoods, a residual X-ray filter in the form of washers made of X-ray translucent material, which are rigidly fixed after behind the hoods in the through holes of the specified additional partition, the lens unit, each of which contains at least measures e two sequentially mounted lenses for focusing a part of the light flux corresponding to this lens, and a photodetector containing optoelectronic converters located after the lenses with partially overlapping fields of view and decoupled electrical outputs for connecting to fragment video signals; (c) an electronic unit for analog-to-digital conversion of fragmentary video signals and their preparation for further processing, which is connected by a multicore cable to the electrical outputs of the optoelectronic converters of the photodetector; and (d) external with respect to the opaque PC case, which is connected to the output of the indicated electronic unit and equipped with a display, recording means and other diagnostic information processing, characterized in that the opaque case is provided with a pocket, which is limited by at least an X-ray-proof wall, said electronic the unit is located in the indicated pocket, and the PC is equipped with software tools for correcting geometric distortions and “stitching” the corrected fragmentary video signals into integral qi rovye video signals and connected to said electronic control unit via a digital interface. 2. The receiver according to claim 1, characterized in that the digital interface is selected from the group consisting of USB, Ethernet and CameraLink.