RU2261465C2 - Method for x-ray control of body (variants) and plant for realization of said method (variants) - Google Patents

Abstract

FIELD: x-rays.

SUBSTANCE: method includes x-ray body control by scanning it with pre-generated collimated beam of x-ray radiation of low power due to synchronous, independent movement relatively to held body of flat, vertical beam of x-rays and sensor, made in form of vertical line of radiation detectors. In other variant body moves relatively to flat, vertical beam of x-rays and sensor, made in form of vertical line of radiation detectors.

EFFECT: higher efficiency, higher precision.

4 cl, 7 dwg

Description

Technical field

The invention relates to the field of technical physics, in particular to the technique of detecting radiation and can be used in photometry, dosimetry, as well as in measuring the spatial and energy characteristics of the fields of optical and ionizing radiation for purposes, for example, x-ray control of bodies, in particular, the human body, for the detection in them or on them of some undesirable objects or substances both for medical control and for non-medical purposes, for example, to prevent theft or acts of terrorism and Sintered safety in buildings, such as airports, banks and other high-risk areas.

State of the art

At present, the issues of controlling bodies, in particular bodies of people, for detecting in them or on them some undesirable objects, objects or substances are acquiring special importance and urgency. This is due, for example, to the need for early detection of various serious diseases, such as neoplasms or tuberculosis. Non-medical applications include the prevention of theft, such as drugs or precious stones and metals, as well as ensuring the safety of flights of air transport, as well as banks, embassies, nuclear centers and other facilities and special institutions.

X-ray introspection of baggage at airports is today the main effective means of ensuring flight safety. Baggage X-ray devices [see EUROP SCAN prospectus], are a conveyor passing through a rectangular frame, in the upper part of which an x-ray source is installed, and in the lower part, under the conveyor, is a sensor. The specified device is not intended to control passengers, because, to increase the resolution, it uses a source with a high level of radiation.

Passengers are monitored for the presence of metal objects under clothing using electromagnetic frames and metal detectors. The X-ray inspection method was not used due to health hazards.

Recently, attempts have been made to implement a low-dose X-ray control, which could be subjected to people without a threat to their health.

A known method and installation of x-ray control [product BodySearch, see prospectus of American Science and Engineering, Inc]. A person is irradiated with a low-power X-ray beam, the radiation reflected (scattered) by the surface of his body is captured, converted into an image, and it is used to judge whether he has, for example, prohibited items. The installation that implements this method has a housing in which a low-power x-ray source, a device for forming an x-ray beam, and a reflected radiation detector are located. Close to the body is a platform that is open on three sides. A person stands on the platform close to the body, face or back to it. A source located at about half the height of a person emits a conical divergent beam of low-power x-ray, which, passing through clothes, is reflected from the surface of the passenger’s body. The reflected radiation is captured by the detector and creates on it a picture of what is on the surface of the body, in the clothes and on the clothes of that half of the body, which is turned to the body. For a complete examination, it is necessary to expose a person to radiation in two positions: face to the body and back to him. In this case, the internal cavities of the body, i.e. it is impossible to detect objects swallowed and located in the stomach or placed in other natural cavities of the body.

In addition, the most sensitive human organs located in the middle part of the body are exposed to the greatest radiation, and the legs and, especially, shoes, which can also serve to transport smuggling, are out of the controller's field of vision.

A known method and installation for x-ray control of the body [US patent No. 54404377, publ. 04.04.1995, patent of Russia No. 21266550, publ. 02/20/1999] by scanning it with a preformed x-ray beam in the form of a flat pack of flat low-power x-ray beams by moving the body and the radiation source relative to each other, receiving radiation passing through the body, creating an optical image from this radiation, transmitting and amplifying of this optical image, electronic image formation and analysis.

In the installation, a radiation source, a special design collimator and a sensor in the form of a matrix of radiation detectors are mounted on a holder that moves relative to a stationary body. Each of the radiation detectors contains devices for forming an optical image from the x-ray radiation transmitted through the body, fiber-optic communication elements, optical image amplifiers and devices for converting the optical image into an electronic image. Imaging tools include said sensor and a processing device for said electronic image.

Since the transmission of information in the form of an optical image is accompanied by significant losses, its intermediate amplification is required. To create an image suitable for conversion to an optical image, a bundle of radiation beams having a certain height is required. A massive holder with devices attached to it cannot move fast enough. Maintaining the minimum dose received by the body, provided the source moves at a low speed in combination with the radiation power passing through the body, sufficient to obtain an optical image, is a difficult task.

Also known scanning x-ray system [European patent No. 271723 A1, publ. 06/22/1988], containing a sensor of x-ray radiation transmitted through the body, made in the form of a vertical line of detectors, and a collimator in the form of a pair of vertical parallel plates for the formation of x-ray radiation.

Known scintillation counter [USSR copyright certificate No. 306770 A, publ. 10.31.1983], containing in one case the first device for converting x-ray radiation transmitted through the body into visible light radiation (scintillator), and a second device adjacent to it for converting visible light radiation into an electric signal (photoelectric multiplier).

SUMMARY OF THE INVENTION

The technical result of the claimed invention is the creation of safe and effective methods and devices for implementing full x-ray control of the body with great accuracy.

In this case, the task also arises of eliminating the influence of changes in environmental conditions on one of the plant modifications.

The problem in the method of x-ray control of the body by scanning it with a preformed collimated beam of low-power x-ray due to the movement of the body and the radiation source relative to each other, reception of radiation passing through the body, formation and analysis of the image in electronic form, is solved due to the fact that the radiation beam is formed in the form of a single planar beam, and the radiation received at each moment of scanning and converted into the radiation of visible light is converted digital electronic signals.

Preferably, the planar beam of radiation is formed vertically.

In one embodiment of the method, the planar radiation beam is moved in a horizontal plane relative to the stationary body, and the radiation sensor is moved in the horizontal plane synchronously with the specified beam. Moving a flat beam of radiation is carried out by moving the collimator horizontally, maintaining the ratio of the speeds of the collimator and the radiation sensor constant. The collimator is moved by means of a drive with a stepper motor, and the radiation sensor is also moved by means of a drive with a stepper motor and synchronized with the movement of the collimator, maintaining the ratio of rotation speeds of these stepper motors.

In another embodiment of the method, the body is moved relative to a stationary source and radiation sensor.

In this case, a flat radiation beam is formed with a divergence angle in the vertical plane of 37-43 ° and positioned so that the horizontal plane passing through the lower point of the body cuts 2-5 ° from the beam.

In the installation of the X-ray control of the body, containing a platform for placing the body, a signal processing device, a low-power X-ray source and a holder with a collimator and a sensor located on it, consisting of radiation detectors, each of which contains the first devices for converting X-rays transmitted through the body , into the radiation of visible light, and second devices for converting the radiation of visible light into an electronic signal, the problem is solved in that the sensor ene as a vertical line of radiation detectors, each of which said first device is adapted to convert into a digital electronic signal and immediately adjacent to said second device.

A collimator made in the form of at least one pair of parallel plates and the sensor are placed vertically.

Preferably, the holder is located horizontally with the possibility of movement in a vertical plane parallel to itself, relative to the platform for housing the body, fixed motionless. On the holder there are horizontal guides for moving a sensor along it, equipped with a stepper motor drive, and horizontal guides for moving a collimator along them, also equipped with a stepper motor drive. The radiation source is fixed with the possibility of rotation around a vertical axis and is connected by a telescopic rod with a collimator. These drives are associated with a control unit for maintaining a predetermined ratio of rotational speeds of these stepper motors. The radiation source is fixed with the possibility of rotation around a vertical axis and is connected by a telescopic rod with a collimator.

In an alternative implementation example of the installation, the holder is U-shaped and mounted vertically, with a linear sensor mounted on one of the racks of the holder, and a collimator in the second rack.

The platform for placing the body is made with the possibility of movement between the uprights of the holder perpendicular to its plane and is equipped with an autonomous engine and guides, the platform is equipped with a fence.

The radiation source is located on the outside of the specified second rack at 20-50% above the platform level. The collimator is mounted inside the specified second stand of the holder. The space between the radiation source and the second counter is closed by an additional casing in the form of a pyramid with a base adjacent to the specified counter and an angle at the apex equal to the largest beam scattering angle; at least one additional collimator made in the form of a pair of parallel plates is vertically placed inside the auxiliary casing.

The sensor can be made of two parts, the upper of which makes up 60-70% of the total height of the sensor and is installed at an angle of 4-6 ° to the vertical towards the platform to accommodate the body.

To eliminate the influence of changes in environmental conditions, the upper crossbar between the vertical uprights of the U-shaped holder is made in the form of four rods threaded into the corresponding holes in the corners of four flat rectangular plates placed in pairs on a third of the length of the rods at each end at equal distances from the end of the rod and between themselves in pairs, with the ends of the rods intended for attachment to vertical uprights.

Brief Description of the Drawings

The drawings show examples of the invention.

Figure 1 shows a General view of the installation according to one of the preferred options for its implementation,

figure 2 - block diagram of the installation of figure 1,

figure 3 is a diagram explaining the geometric principles of constructing a motion system,

figure 4 is a General view of the installation according to another preferred embodiment of the invention,

figure 5 is a schematic representation of the action of the installation in figure 4,

figure 6 - design of the upper crossbar of the installation of figure 4,

Fig.7 is a diagram illustrating the movement through the installation of Fig.4,

DETAILED DESCRIPTION OF THE INVENTION

The present invention can have many diverse applications and will be illustrated by the example of two of them: medical - the installation of figure 1-3, and non-medical - the installation of figure 4-7.

The medical device according to the invention, shown in FIG. 1, comprises a holder 1 with a collimator 2 and a sensor 3 located thereon, a low-power X-ray source 4, a platform 5 for housing the body 6, and an information processing device 7 (see FIG. 2). The sensor 3 is made in the form of a vertical line of radiation detectors 8, each of which contains a device 9 for converting visible light into a digital electronic signal, which is directly adjacent to a device 10 for converting x-ray radiation transmitted through the body into visible light, for example, scintillation type .

The collimator 2, made in the form of at least one pair of parallel plates 11, and the sensor 3 are placed vertically.

The information processing device 7 (see FIG. 2) comprises an interface unit 12 and a device for processing received signals 13, for example, in the form of an operator’s computer workstation. The interface unit 12 is designed to control all installation units, verify their operation, conversion and primary processing of information. It is also used to communicate with the device 13 for processing the received signals, as well as to enable the block 13 to be substantially remote from the x-ray source 4 in order to reduce the dose burden on maintenance personnel.

In this installation, the holder 1 is mounted on the support 14 horizontally with the possibility of moving in a vertical plane parallel to itself, relative to the platform 5 for housing the body 6, in particular the patient, fixed motionless. On the holder 1 there are horizontal guides 15 for moving the sensor 3 along it, equipped with a drive with a stepper motor 16 and horizontal guides 17 for moving along them a collimator 2, also equipped with a drive with a stepping motor 18. A radiation source 4, as shown in FIG. 1, mounted on a hinge 19 with the possibility of rotation around a vertical axis and connected by a telescopic rod 20 with a collimator 2.

The installation is also equipped with a control unit 21 for maintaining a predetermined ratio of rotational speeds of the collimator and sensor stepper motors, as well as a power unit 22, with corresponding connections (not shown) for supplying the unit with the necessary voltages.

In the described installation, the inventive method is implemented in the process as follows.

The investigated body 6, in particular the human body, we will call him “patient” for this case, placed on the platform 5. Move the holder 1 in a vertical plane and achieve the correct location of the collimator 2 and sensor 3 relative to the investigated area of the patient’s body 6 depending on the growth of the latter . The collimator 2 and the sensor 3 are set so that a flat vertical beam of x-ray radiation with high accuracy falls on the vertical line of radiation detectors 8 constituting the sensor 3. The stepper motors 16 and 18 are turned on and the collimator 2 and sensor 3 begin synchronous movement along the respective horizontal guides 15 and 17. The x-ray source 4 emits a stream from which the collimator 2 forms one flat vertical beam by means of its two vertical plates 11.

The principles for constructing a synchronization of a motion system are shown in FIG. 3. During scanning, the sensor 3 and, accordingly, its radiation detectors 8, moves at a constant speed from point A to point B. In parallel with the movement of the sensor, the collimator 2 moves from point E to point F so that the shadow projection of the slit of the collimator 2 from the flow X-ray radiation emanating from point O, constantly falls on the detectors 8.

The radiation source 4 is located at point O. The direction of its maximum radiation synchronously with the scanning of the sensor 3 and the slit of the collimator 2 changes in such a way that it is constantly on the OS line.

Since the motion of the collimator 2 occurs at a constant speed along the chord of a circle centered at point O, the angular velocity of rotation of the emitter 4 at point O will be unstable. Ensuring the synchronization of the motion system is achieved due to the fact that when the collimator 2 is moved, the telescopic rod 19 of the emitter 4 rigidly connected with it rotates around the point O, at which the radiation center is located.

Moreover, as evident from considerations of similarity, to ensure the constancy of the projection of the collimator 2 onto the detectors 8 in the entire scanning range, it is enough that the movement of both elements in time occurs according to the same law. This principle of constructing a motion system allows its technical implementation to be relatively simple means, because for synchronous movement, it is sufficient to ensure the movement of the collimator 2 and the sensor 3 with constant speeds.

The coordinated movement of the collimator and the sensor can be achieved in this case only if the ratio of their velocities is maintained with very high accuracy. Since the rotation speed of the stepper motors is ultimately determined by the switching frequency of its windings, the task of synchronous movement of the tables is reduced to the synthesis of two frequencies with a strictly defined ratio. Moreover, it is necessary to be able to change this relationship with very small increments. In addition, to increase the smoothness of the motion of the collimator and the sensor and the consistency of their work, the method of crushing the engine steps by 8 times was used. This circumstance leads to the fact that the switching frequency of the motors also increases by 8 times.

Considering that the angular rotational speeds of the step motors of the collimator and the sensor are 10 and 2 revolutions per second, respectively, the number of steps per revolution is 200, and the crushing coefficient is 8, - the calculated frequencies controlling the motors will be respectively 16000 and 3200 Hz, those. stepper motors take 12800 and 3200 crushed steps per second, and with a scan time of 4 seconds, the collimator and sensor take 64000 and 12800 steps, respectively. It is easy to calculate that the price of the sensor step 3 with a number of steps equal to 12800 and a working stroke of 600 mm is approximately 50 μm, i.e. to ensure synchronization of the stroke with an accuracy of 50 μm, it is necessary that the number of sensor steps during the scan is maintained with an accuracy of one step, which means that the frequencies must be maintained with an accuracy of no worse than 1/12800. With the same increments (1/12800), it is necessary to be able to change the frequencies to ensure the selection of their necessary ratio.

The solution to this problem was made possible by relatively simple hardware due to the fact that the two control frequencies are quite significantly different from each other (about five times). This made it possible to construct an electronic synchronization circuit as follows. Block 21, using the appropriate program, synthesizes the reference rotational speed of the collimator motor (higher frequency), which is approximately 62,000 Hz. The accuracy of selecting this frequency may not be very high, since only the scanning time depends on it and the coordination of movement does not depend. For each pulse of the reference frequency, a sequential interrogation of the RAM array is performed, into which a lower scanning frequency of the sensor is recorded. The volume of this memory array is 65536 bits, i.e. slightly exceeds the number of steps of the collimator. Therefore, the position over the entire scanning area can be calculated and stored in memory with an accuracy of one step. The array recorded in the RAM is calculated by the computer on the basis of the data obtained during the setup and adjustment of the entire system. The array stored in the computer is individual for each device. Its loading into the memory of the microcontroller is carried out immediately after turning on the device and occurs automatically without operator intervention.

Sensor stroke 3, i.e. the distance between points A and B is 600 mm. The stroke of the collimator 2, i.e. the distance between points E and F is 150 mm. The distance H along the central axis 00 'between the center of rotation O and the plane of movement of the sensor 3 is 1600 mm. The distance h between the center of rotation and the plane of movement of the collimator 2 is 400 mm The distance h 'between the center of rotation and the patient’s placement plane (indicated by the dashed line) depends on the parameters of the patient and lies in the range 800–900 mm, i.e. 400-500 mm away from the plane of movement of the collimator 2 The geometric factor of the object (scaling factor) K, which refers to the ratio of the sizes of the shadow projection of the patient on the plane of movement of the sensor 3 to the actual size of the patient, will be equal to:

K = H / h '= 2

The patient’s scanning time T, during which the sensor 3 moves from point A to point B, can take four fixed values: 2, 4, 8, and 16 seconds. The main mode of operation corresponds to a scan time of 4 seconds, at which the speed V of the movement of the sensor 3 will be equal to:

V = AB / T = 600/4 = 150 mm / s,

and the velocity v of the motion of the collimator 2 will be equal to:

v = EF / T = 150/4 = 37.5 mm / s.

In this mode (with a scan time of 4 seconds), the probe 3 is polled for t = 10 ms (0.01 sec). During this time, the sensor 3 will move to a distance S equal to

S = V · t = 150 · 0.01 = 1.5 mm

Obviously, this value (1.5 mm) will correspond to the spatial resolution of the detected image of the patient on the sensor plane along the horizontal axis. Given the geometric increase, the spatial resolution s on the plane of the object will be

s = S / K = 1.5 / 2-0.75 mm

Therefore, the motion parameters and the geometry of the motion system provide a spatial resolution of the image of the object along the horizontal axis of 0.75 mm. The change in spatial resolution with a change in the scanning speed is directly proportional, i.e. with decreasing speed, spatial resolution improves.

The sensor 3 may also be two vertical lines of X-ray detectors 8, shifted by half the placement step of the detectors 8. The interrogation of these lines during the scanning process can be either sequential or parallel. The spacing of the detectors 8 is 1.55 mm. The vertical spatial resolution on the plane of the sensor in this case will be half the pitch of the detectors 8, i.e. about 0.8 mm. Taking into account the twofold geometric increase (the coefficient of geometric increase of the object K = 2), the vertical spatial resolution on the plane of the object will be 0.4 mm.

The x-ray beam passing through the patient’s body 6 at any given scan moment enters devices 9, for example, the scintillation type, and is converted into visible light. This light is captured by devices 10 directly adjacent to devices 9 and converted into digital electronic signals. Interrogation of the sensor 3, as already indicated, is carried out in 10 ms. The output digital electronic signals through the block 12 of the interface are supplied to the device 13 for processing information. The dose received by the patient in one shot is from 0.3 to 0.9 mR.

The movement of the light sensor and collimator can be carried out practically without inertia, the speed is regulated over a wide range. The direct conversion of light signals into digital electronic eliminates losses and allows for effective control of particularly small doses of x-ray radiation.

In an alternative example of the implementation of the installation of non-medical purposes, shown in Fig.4-7, the elements matching the elements of the medical installation are indicated by the same numbers.

In this implementation, the holder 1 is U-shaped and mounted vertically, with a linear sensor 3 mounted on the first rack 23 of the holder 1 and a collimator 2 in the second rack 24. The platform 5 for housing the body is movable between the racks 23 and 24 of the holder 1 perpendicular to its plane and equipped with an autonomous engine and guides (not shown).

The radiation source 4 is located on the outside of the specified second rack 24 20-50% above the level of the platform 5. The collimator 2 is fixed inside the specified second rack 24 of the holder. The space between the radiation source 4 and the second column 24 is closed by an additional casing 25 in the form of a pyramid with a base adjacent to the column 24 and with an apex angle equal to the largest beam scattering angle. As shown in FIG. 5, this angle is about 43 °.

At least one additional collimator 26, made in the form of a pair of parallel plates, is vertically placed inside the additional casing 25.

The sensor 3, as shown in FIG. 5, can be made of two parts, the upper of which is 60-70% of its total height and is installed at an angle of 4-6 ° to the vertical towards the platform 5.

The design of the upper crossbar between the uprights 23 and 24 of the holder 1 is shown in Fig.6. It consists of four rods 27 threaded into the corresponding holes 28 at the corners of four flat rectangular plates 29. The plates 29 are placed in pairs on a third of the length of the rods 27 at each end at equal distances from the end of the rod and in pairs in pairs. The ends of the rods 27 are designed to be attached to the uprights 23 and 24.

The platform for placing the body is equipped with a guard 30.

The installation also includes an information processing device 7, which contains an interface unit 12 and a device 13 for processing received signals, for example, in the form of an operator's computer workstation. There is also a power supply (not shown) to supply the unit with the necessary voltages.

In the described installation, the inventive method is implemented in the process as follows.

A flat vertical x-ray beam is formed from the radiation emitted by the source 4 first with at least one additional collimator 26 placed vertically inside the additional casing 25. This casing protects the beam from being accidentally crossed by any object or body. Then the flat vertical shape of the beam is additionally attached using the main collimator 2, mounted in the rack 23. As a result, an x-ray beam with a scattering angle in the vertical plane of 37-43 ° is obtained. The collimator 2 and the sensor 3 are installed in the racks 23 and 24, respectively, so that a flat beam always hits the vertical line of radiation detectors 8 that make up the sensor 3. The body under study 6, in particular the human body, we will call him “passenger” for this case, is placed on platform 5, moving from the first side. The guard 30 provides the passenger with support when the platform 5 is moving and prevents a possible fall from the moving platform 5. Owing to an autonomous engine, for example an electric (not shown), the platform moves between the uprights 23 and 24 so that the passenger 6 crosses the indicated flat vertical x-ray beam, and horizontal the plane bounding the body from below, i.e. the upper surface of the platform 5, cuts off 2-5 ° of the beam. The x-ray beam passing through the body of the passenger 6 at each given moment of scanning enters the device 9, for example, the scintillation type, and is converted into visible light. This light is captured by devices 10 directly adjacent to devices 9 and converted into digital electronic signals. The output digital electronic signals through the block 12 of the interface are supplied to the device 13 for processing information. The examined passenger 6 leaves the platform 5 on the other side opposite the indicated first side (see figure 7).

The equivalent radiation dose received by a person during examination in non-medical settings is the most critical parameter for them. Calculation of equivalent doses for x-ray screening of people is currently carried out only with medical x-ray examination of patients. It is for medical radiology that a number of computer programs have been developed in various countries of the world. The equivalent dose received by a person during examination in the inventive installation of non-medical purposes, was tentatively estimated using known equipment and methods.

To determine the input dose, the Alderson-Rando phantom and the NOMEX kit from PTW-Freiburg (Germany) were used, including a flat type 77335 ionization chamber with a volume of 112 cm ³ .

The energy range of the camera calibration is in the range from 39 keV to 95 keV, while the correction factor decreased from 1.04 to 0.99.

When conducting measurements on the inventive non-medical device, a complex filter of 6 mm A1 + 0.5 mm Cu was used. The voltage on the tube varied from 120 to 200 kV. The effective radiation energy varied from about 70 to 120 keV. It was decided to take the correction factor of the energy dependence of the camera sensitivity K _q equal to 1.

The measurement results are presented in table 1.

Table 1. Tube voltage, kV Tube current, mA Air kerma, μGy 1 2 3 The camera is located at the chest level of the phantom 120 1 0.375 0.351 0.354 0,357 120 2 0.612 0.612 0.624 120 3 1.002 0,999 1,029 120 4 1,338 1,350 1.359 120 5 1,611 1,623 1,638 120 7 2,268 2,277 2,289 130 1 0.438 0.438 0.426 130 2 0.804 0.804 0.801 130 3 1,275 1,290 1,278 130 4 1,701 1,722 1,719 130 5 2,094 2,094 1 2 3 2,097 2,100 130 6 2,520 2,532 2,524 140 1 0.519 0.516 0.519 140 2 1.002 1.002 140 3 1,611 1,611 140 4 2,163 2,172 140 5 2,607 2,628 140 6 3,108 3,129 150 1 0.648 0.654 150 2 1,224 1,233 150 3 1,983 1,938 150 4 2,661 2,655 150 5 3,243 3,273 160 1 0.741 0.759 160 2 1,404 1,461 1,452 160 3 2,331 2,337 160 4 3,138 3,162 160 5 3,870 3,879 170 1 0.885 0.885 170 2 1,725 1,728 170 3 2,730 2,784 170 4 3,705 3,753 170 5 4,569 4,563 180 1 1.011 1.002 180 2 1,962 1,953 1 2 3 180 3 3,171 3,171 180 4 4,266 4,275 180 5 5,259 5,262 190 1 1,206 1,212 190 2 2,310 2,301 190 3 3,657 3,672 190 4 4,956 4,998 200 1 1,392 1,398 200 2 2,652 2,643 200 3 4,209 4,212 background measurement 0 0 0,033 0,030 Measurements behind the phantom camera at chest level 190 4 0.450 0.462 150 3 0.183 0.189 Abdominal Camera 150 3 2,247 2,250 190 2 2,610 2,652 150
190 Head level camera
3
2 1,443
1,428
1,566
1,752

An analysis of the data shows that the doses in the lower body were higher than at the level of the head. This is not surprising, since the emitter is located at a distance of about 40 cm from the floor, and the source-object distance in the lower part of the body is less than in the upper.

The calculation of the effective dose was carried out using the program "ORGDOSA", which is an analogue of the program PDS-60.

Since the program was created to determine the effective dose for a medical X-ray diagnostic examination, the exposure conditions at the claimed non-medical device do not fit the boundaries of the parameters included in the program. In general, the limitations of the parameters in the program are the same as in the devices for measuring doses: the source-object distance is not more than 200 cm, the maximum voltage on the tube is not more than 150 kV, the minimum input dose is at least 10 μGy, etc. Therefore, when calculating the effective dose, it was necessary to take into account the well-known physical laws of the interaction of X-rays with matter, namely:

1. with the same filter, increasing the voltage on the tube reduces the input dose;

2. an increase in the distance of the source-object with constant parameters of the tube leads to a decrease in the input dose;

3. the program does not provide for translucency of the whole body, therefore, when calculating the radiation field was divided into separate components - head, chest, abdomen, pelvis and hips, the effective dose to the whole body from each component was calculated and then summation was carried out. The contribution to the total dose from the legs and feet was not taken into account, since the Alderson-Rando phantom does not have them, and measurements at this level were not performed;

4. the calculation was carried out for the minimum input dose recorded in the program - 10 μGy, and then the effective dose was reduced to the measured input dose at the level considered.

An example of calculating the effective dose when radiating the Alderson-Rando phantom on the claimed non-medical device:

The voltage on the tube is 150 kV.

The tube current is 3 mA.

The distance from the source to the input surface of the object is 200 cm.

The sizes of the irradiation field were chosen for each level: head, chest, abdomen, pelvis and hips.

D _eff = 0.11 μSv for the head,

D _eff = 1.04 μSv for the breast,

D _eff = 1.19 μSv for the abdomen,

D _eff = 1.13 μSv for the pelvis,

D _eff = 0.76 μSv for the hips,

D _eff = 4.23 μSv in total.

Thus, it is possible to roughly estimate the effective dose for examining people at the claimed non-medical device as not exceeding 5 μSv for any transmission regimes in the range of tube voltages exceeding 150 kV and tube currents not exceeding 3 mA. These results can only be considered preliminary.

Due to the fact that the scattering angle of the x-ray beam is 37-43 °, and also due to such a low location of the radiation source 4 that the upper surface of the platform 5 cuts off 2-5 ° of the beam, a complete introspection of the entire passenger body from head to shoes with revealing on and in the body of foreign objects.

The inclination of the upper part of the sensor 3 by 4-6 ° in the direction of the platform 5 allows you to compensate for the extension of the radiation path to this part of the sensor 3, and thus avoid the deterioration of the image quality of the upper body.

As can be seen from figure 4-7, this modification of the installation must be performed with a height of not less than 2.5 meters to ensure control of passengers of any height. However, a U-shaped structure of such dimensions is sensitive to vibrations and the influence of environmental changes, such as temperature. When the temperature changes, the structure will warp, which will lead to the displacement of the flat beam from the linear sensor 3. To eliminate this effect, the upper crossbar of the holder is made as described above (see Fig.6). The rods 27 redistribute the emerging stresses into four rectangular plates 29, which, in turn, redistribute and quench the voltage.

This, in turn, makes it possible to significantly reduce dose loads during examinations and improve the quality of x-ray images. Using the proposed technical solutions allows us to conduct safe x-ray studies not only of patients (patients), but also of large contingents of healthy people, such as passengers.

The present invention is not limited to the examples given.

Claims (23)

1. The method of x-ray control of the body by scanning it with a preformed beam of low-power x-ray radiation by moving the beam and the sensor relative to the stationary body, receiving radiation passing through the body, converting it into visible light radiation, which, in turn, is converted into electronic signals , forming and analyzing an image in electronic form, characterized in that the x-ray beam formed by a flat vertical, and the sensor is moved synchronously in the burn ontalnoy plane. 2. The method according to claim 1, characterized in that the movement of the flat beam of x-ray radiation is carried out by moving the collimator horizontally, maintaining a constant ratio of the speeds of the collimator and the sensor. 3. The method according to claim 2, characterized in that the collimator is moved by means of a stepper motor. 4. The method according to claim 3, characterized in that the movement of the sensor is carried out by means of a stepper motor, and the synchronization of the motion of the collimator and the sensor is carried out by maintaining a given ratio of rotational speeds of both stepper motors. 5. The method according to claim 1, characterized in that the radiation of visible light obtained from x-ray radiation received at each moment of scanning is converted directly to digital signals. 6. Installation of x-ray control of the body, containing a platform for placing the body, an information processing device, a low-power x-ray source and a holder with a vertical collimator and a sensor located on it, which is made in the form of a vertical line of radiation detectors, each of which contains a first device for converting x-ray radiation that has passed through the body into visible light radiation, and a second device adjacent thereto for converting visible light radiation into elec Throne signal, characterized in that it is provided with two guides and a collimator and x-ray detector are movable for independent movement of said guide. 7. Installation according to claim 6, characterized in that the collimator is made in the form of at least one pair of parallel plates. 8. Installation according to claim 6, characterized in that the guides for moving the sensor along them and the guides for moving the collimator along them are placed horizontally on the holder. 9. Installation according to claim 6, characterized in that the collimator is equipped with a stepper motor drive. 10. The installation according to claim 9, characterized in that the sensor is equipped with a drive with a stepper motor and a control unit to maintain a predetermined ratio of rotational speeds of the stepper motors of the collimator and the sensor. 11. Installation according to claim 6, characterized in that the x-ray source is mounted rotatably around a vertical axis and is connected by a telescopic rod to the collimator. 12. Installation according to claim 6, characterized in that the holder is located horizontally with the possibility of movement in a vertical plane parallel to itself, relative to the platform for placing the body, fixed motionless. 13. The installation according to claim 6, characterized in that the second device of the radiation detector is made to convert the radiation of visible light directly into a digital signal. 14. The method of x-ray control of the body by scanning it with a preformed beam of low-power x-ray radiation, receiving radiation passing through the body, converting it into visible light radiation, which, in turn, is converted into electronic signals, forming and analyzing the image in electronic form, characterized in that the body is moved along a horizontal plane relative to a fixed x-ray beam, which is formed flat vertical with at least one additional body collimator, placed vertically inside the additional casing, and then with the help of the main collimator, mounted in an appropriate rack. 15. The method according to 14, characterized in that the x-ray beam is formed with a divergence angle in the vertical plane of 37-43 °. 16. The method according to 14, characterized in that the x-ray beam is positioned so that a horizontal plane passing through the lower point of the body cuts off the beam 2-5 °. 17. The method according to 14, characterized in that the radiation of visible light obtained from x-ray radiation received at each moment of scanning is converted directly to digital signals. 18. A body X-ray control apparatus comprising a body accommodating platform, an information processing device, a low-power X-ray source, and a holder with a collimator and a sensor disposed on it in the form of a vertical line of radiation detectors, each of which contains a first device for converting X-ray radiation passing through the body into the radiation of visible light, and a second device adjacent to it for converting the radiation of visible light into an electronic signal, o characterized in that the holder is U-shaped and mounted vertically, and the platform for placing the body is movable to move in a horizontal plane between the posts of the holder perpendicular to its plane, while the linear sensor is mounted on one of the posts of the holder, and the collimator is inside the second rack, on the outside of which there is a radiation source located 20-50% above the level of the platform so that the upper plane of the latter cuts off 2-5 ° from the x-ray beam. 19. Installation according to claim 18, characterized in that the space between the x-ray source and the second column is closed by an additional casing in the form of a pyramid with a base adjacent to the column and an angle at the apex equal to the largest beam divergence angle. 20. The installation according to claim 19, characterized in that it is equipped with at least one additional collimator, made in the form of a pair of parallel plates, placed vertically inside the additional housing. 21. Installation according to p. 18, characterized in that the sensor is made of at least two parts, the upper of which is 60-70% of the total height of the sensor and is installed at an angle of 4-6 ° to the vertical towards the platform to accommodate the body. 22. Installation according to p. 18, characterized in that the upper crossbar between the vertical uprights of the U-shaped holder is made in the form of four rods threaded into the corresponding holes in the corners of four flat rectangular plates placed in pairs on a third of the length of the rods at each end thereof equal distances from the end of the rod and between each other in pairs, and the ends of the rods are designed for fastening to vertical racks. 23. The apparatus of claim 18, wherein the second radiation detector device is configured to convert visible radiation directly into a digital signal.

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