HU195383B - Device for adjusting parameters of exposure of an x-ray equipment - Google Patents

Abstract

An apparatus for setting the exposure parameters of an X-ray equipment, in which the control function is shared between a machine-dependent control block including a microcontroller and a personal computer. The control block is arranged to adjust various settings of the X-ray equipment and to control the conditions that must be provided between these parameters for a trouble-free operation and to provide an interface towards the personal computer, while the personal computer is used in a dialogue mode by the X-ray personnel to select the required examination and to adjust the actual conditions of an examination.

Description

The present invention relates to the field of control of X-ray generators, and more particularly to apparatus for adjusting the exposure parameters of high voltage, X-ray tube current and exposure time.

It is well known in the field of x-ray technology that the exposure parameters must be adjusted by the x-ray physician or the operating staff for each x-ray, according to the examination that is currently required. The parameters, expressed in milliamperes and seconds (milliseconds), can be varied within wide limits for any X-ray equipment, and despite their practical experience, X-ray doctors will determine the type of examination to be performed rather than the technical parameters for such examinations.

The high cost of X-rays and the need to reduce radiation exposure to patients require the use of optimum images. The value of the recording parameters depends mainly on the body part under investigation and many different tests can be performed within one body part. The number of tests that can be performed is hundreds, and X-ray equipment staff cannot be expected to know the exact value of the optimal parameters for each type of examination. The parameters of optimum uptake exposure depend not only on the type of examination but also on the subject and the patient's condition. Such conditions include age, gender, weight, and many other individual characteristics. In addition, there are other factors that influence the exposure parameters, such as the X-ray equipment and the technical characteristics of the X-ray film. Such features include, for example, the sensitivity of the film or video system used, the possible use of a screening grid, the imaging distance, etc.

Setting the optimum parameters requires artificial intelligence, and more recently, the use of computers.

There are now many types of computer-supported X-ray generators that use a special purpose computer to help set the necessary exposure parameters. A typical example of such a control is the control unit POLYDOROS 50/80/100 of Siemens in the Federal Republic of Germany. In this control unit, a matrix of 7 rows and 7 columns is used on the control surface, beside the rows is an image of a standing human figure, each row is assigned to a body part at a given height, and the columns belong to various possible examinations of that body part.

The selection of the test is selected by clicking on the field at the intersection of the appropriate column and row, and this selection will display a caption indicating the type of test selected and display the parameters associated with the currently selected test. In addition to selecting a test, the control unit also allows you to set some conditions.

This type of control is of great help to the operator when adjusting the exposure parameters. However, the use of such special purpose computers limits the possibilities in several ways. The first limiting factor is the organization of the keyboard. The treatment of a matrix with 7 rows and 7 columns is already on the verge of confusion when selecting an assay. However, the possible and the tests to be performed require a more fine-grained distinction, which the aforementioned known design solutions can no longer provide. The limited size of the keypad determines the maximum number of possible settings, that is, only so many conditions can be considered when selecting an exposure.

The design of the control unit is closely related to the X-ray generator for which it was designed and can no longer be used for a different X-ray generator. If, as a result of technical progress, new devices are introduced or new conditions are created which need to be considered when selecting exposure parameters, these types of control units can no longer meet these requirements.

There is another problem with costs. Special purpose computers are priced much higher than mass-produced general purpose computers or personal computers because of their small series production.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus for adjusting the exposure parameters of an x-ray machine which does not limit the number of body parts and the number of tests that can be distinguished within it and allows the scale or scale of such tests to be varied or it can take into account the different circumstances of the study and their changes, and finally it can be used for other purposes.

In accordance with the present invention, it has been recognized that a distinction needs to be made between conditions that are dependent on a particular X-ray equipment and conditions that can only be selected by the operator according to the particular examination. The first set of conditions is satisfied by a control unit that coordinates various machine-dependent tasks and, in addition to this function, provides an interface connection to a general-purpose computer from which to receive the specific information defining the recording, a second set of conditions with a general-purpose computer, for example, a personal computer that can be programmed so that the required examination and test conditions are selected by the attending physician in dialogue with it. Sharing the control fclniln case between the two intelligent devices offers many advantages. First of all, PCs are widely known, are relatively simple and hassle-free programming, and low in commodity performance, and can be used for other purposes besides setting shooting parameters, such as assisting with X-ray department administration or servicing multiple X-ray equipment. can be done, etc.

The special purpose control unit thus eliminates many complex tasks and can therefore be manufactured at a lower cost and at the same time ensures the optimum reliability and performance of the associated X-ray equipment.

According to the invention, The device will now be described in more detail with reference to the drawings. In the drawing it is

Figure 1 is a general block diagram of the apparatus according to the invention, a

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Figure 2 illustrates in greater detail the structure of the control unit and the X-ray apparatus, a

Figure 3 is a flowchart of information-based adjustment of exposure parameters from a personal computer, a

Figure 4 shows the screen image when selecting a body part,

Figure 5 shows the screen image when selecting a test, and

Figure 6 illustrates the screen image after making both choices.

Figure 1 is a general block diagram of the system of the invention. The arrangement consists of three main functional units, such as known X-ray units 100, 200 control units and 300 personal computers. The units for X-ray equipment 100 are described only in the depth necessary to understand the operation of the control. X-ray equipment 100 is provided with an X-ray tube 101 whose anode and cathode are connected to a high-voltage transformer 103 through a high-voltage rectifier 102. The primary winding of transformer 103 is connected to a voltage regulator 104 of known design, which has voltage adjusting control inputs for adjusting the voltage of transformer 103 in accordance with preset values of control unit 200.

The X-ray heating filament 101 is powered by a heating transformer 106, its primary coil being coupled via a current chopper 107 to the output of the heating generator 230 for the control block 200. The effective value of the chopper 107 output voltage determines the amount of current flowing through the X-ray tube 101 during exposure.

The Exposure Duration is determined by a timing unit 108 connected, for example, to the control input of the voltage control unit 104. The duration of the timing provided by the timing unit 108 is the same as the timing pulse sent from the control unit 200 to the timing unit 108. Rotation of the anode 101 of the X-ray tube is provided by the anode rotation unit 109, which is powered by the appropriate voltage applied to the anode rotation control unit 110. The anode rotation control unit 110 receives a rotation control command from the control unit 200.

The auxiliary device block 111 denotes known devices and units which can be connected to or used with the X-ray equipment according to the emerging needs. This may include, for example, a screening grid, an automatic recording control unit, an automatic brightness control, a light control unit, a unit that connects the tomograph, etc. With regard to the auxiliary equipment, it should be noted that the control unit 200 receives an indication of their operation (or presence) via the connection terminal 50 and, if the operation requires a control signal, is sent by the control unit 200 via the connection terminal 60.

The control block 200 and the sanctuary 300! the job of the computer is to set up and control the operation of the X-ray apparatus 100. This task is shared between the personal computer 300 and the control unit 200 such that the personal computer 300 provides a high degree of flexibility and handling convenience in determining and adjusting the recording parameters, and the control unit 200 provides an intelligent interface for actual configuration of the X-ray machine 100. coordinates the various control processes and provides appropriate protection.

The main unit of the control unit 200 is a microcontroller 210 which is preferably configured with an 8051 microprocessor of the INTEL company in the United States.

Microcontroller 210 is connected to control unit 220 kV which is connected via terminal 10 to control input 104 of voltage regulator 104 and heater 230 which controls terminal 107 via terminal 20 and timer controller 240 through terminal 30 , fourth, with anode rotation control unit 250, which is connected via terminal 40 to anode rotation control unit 110. The microcontroller 210 has a standard serial interface interface 260 and communicates with a personal computer 300 via a 70 serial data link. Via an additional terminal, the microcontroller 210 is also connected to a custom-designed exposure button. The microcontroller 210 receives information about the various states of the X-ray apparatus 100 through connections not shown in the drawing. Such a connection is required to interrupt or disable recording if the parameters actually set do not match those required by the control block 200.

4, 2 shows a more detailed functional block diagram of the control block 200. As mentioned above, the microcontroller 210 is comprised of, for example, an INTEL 8051 microprocessor. Figure 2 also illustrates the internal structure of the microprocessor. Microcontroller 210 has a serial interface 211, which includes an input buffer that receives and stores serial data received from the personal computer 300 via interface connection 260 and an RXD input data line, and provides a temporary interface for data sent to the personal computer 300 via the TXD output data line. storage. Microcontroller 210 includes processor 212, random access memory 213, read-only memory 214, first and second timers 215, 216 and a plurality of connection terminals, each having a given number of input and / or output connections. Terminal 0 has eight connections, through which kV and exposure time are set. Terminals 1-3 are assigned to various auxiliary functions, such as communication to the exposure button 82, adjustment of the anode rotation, connections to the auxiliary unit block 111, and reception of status information from various functional blocks of the X-ray equipment 100.

The mA of the X-ray apparatus 100 is adjusted by means of a first timer 215 which produces a pulse sequence of frequency determined by the microcontroller 210. The output of timer 215 is connected to a frequency converter 231 which generates an output voltage signal based on the frequency of the input pulses. This voltage signal is connected to the control input of a voltage-controlled power supply unit 232 that otherwise operates at a specified supply voltage Ug. The voltage-controlled power supply 232 feeds through the terminal 20 the current chopper 107 of the X-ray apparatus 100 with an output voltage that is dependent on the voltage applied to its input. The current 107 is 3

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the chopper output drives the primary winding of the transformer 106 via the sensor resistor R. The voltage across the sensor resistor R is detected and collapsed by a comparator 233 when the current flowing through the sensor resistor R falls below a certain threshold level. The tilted state of comparator 233 indicates to microcontroller 210 that the heating current is outside the allowable range.

Use the first connection of the 0 terminals to set the exposure time. If all the conditions required for shooting are met, the 2J0 microcontroller transmits a pulse of the same length as the exposure time to this connection. The timing controller 240 is actually a separating amplifier which sends a corresponding drive pulse to the timing unit 108 in the X-ray equipment 100.

The kV of the X-ray apparatus 100 is set by the voltage regulator 104. In a preferred embodiment of the high-voltage setting, the high-voltage transformer 103 has a plurality of primary windings which are coupled to a switch output 112 (Fig. 2). The switching unit 112 is operable according to the prescribed combinations, and each combination has a specific number of turns of the primary winding of the transformer 103, so that the value of the high voltage generated on the secondary winding is adjusted accordingly. The switching unit 112 is actuated by a relay 113, which is powered via the terminal 10 from the 220 kV control unit. The 220 kV control unit has the same number of stages as the number of relays 113 and has the corresponding number of input lines. In the embodiment outlined in Figure 2, this number is seven and includes terminals 1-7 of terminals 0. For example, the 220 kV control unit may be constructed from known drives of the American SPRAGUE Corporation ULN 2803.

The anode rotation is controlled through the connection r of the microcontroller terminals 1 by enabling the anode rotation control unit 250 to operate. The latter unit comprises a separation amplifier and other relay and serves to generate a voltage signal through the terminal 40 to the anode rotation control unit 110.

In order to understand the setting and control of the X-ray apparatus 100 by the control unit 200, assume that the personal computer 300 generates at least the following three information for the microcontroller 210:

(a) the value of kV in the form of a code combination which defines the logic states of the 1 to 7 connections of the 0 terminals associated with that value;

b) the value of the current flowing through the X-ray tube during exposure, in mA, the frequency code to be provided by the first timer 215;

(c) the duration of exposure, ie the SCR.

These three information are sent by the personal computer 300 to the microcontroller 210 in the form of a sequential signal through a serial data link.

The logical framework for operation is illustrated in Figure 3, which is a flow chart of major events that occur during exposure. The first decision is that the processor 212 should check the actual status of the serial buffer 211 of the interface. If there is data in the buffer (data specific to the kV code first), the process starts and the kV code in the buffer is applied to terminals 0 (1 to 7 of its terminals). The next decision is similar, so processor 212 checks that the serial puffcr state is charged -c (now, charge is represented by the presence of mA information). If the serial buffer contains data for mA, the frequency code defining the flowing current is updated from the serial buffer to the timer 215, and then the timer 215 is started and this generates a pulse sequence at the frequency so determined. This frequency is converted by the frequency converter 231 to a voltage signal which determines the distribution ratio of the controlled power supply 232, i.e. the magnitude of the output voltage. The current chopper 107 then produces a rectangular signal which is transmitted to the heating transformer 106 and thus the X-ray tube 101 rises.

The next step involves a similar decision, and if the following information (regarding the duration of exposure) is available in the buffer, the corresponding time code is written to the second timer 216. When this is done, processor 212 activates terminal r of terminal 1, causing the anode rotation to begin. Then, a waiting period of a certain length begins, which depends on the transient duration of the anode rotation, the stabilization of the filament temperature, and the time required to set the switching unit 112. The waiting time is slightly longer than the longest of these three conditions. After the waiting time has elapsed, the device is ready for recording and the processor 212 continuously monitors the status of the exposure button 82. When the active position of the button 82 is detected (i.e. when the button 82 is pressed), the second timer 216s starts and the connection o of the terminals 0 becomes active. This causes the timer controller 240 to receive a timer pulse, and exposure starts at the set parameters.

The processor 212 now examines the status of the second timer 216, and when timing is complete, it terminates the active state of the connection o and resets the timer 216. This also means the end of exposure. Now, from the read-only memory 214, a basic frequency value is written to the first timer 215, the value of which is consistent with the degree of preheating to be performed between successive recordings. The terminals 1-7 of the terminals 0 are reset, thereby releasing the switch unit 112. The anode rotation is also stopped. The control unit 200 returns to its initial state and a new exposure can be adjusted and triggered.

From this mode of operation, it can be seen that the use of the control block 220 provided with the microcontroller 210 essentially solves all the tasks involved in coordinating the operating phases required to perform a recording. As a result of this alignment, only the three parameters mentioned, kV, mA and secundum, are required to perform the recording, and a data transmission line on a standard line is sufficient. In other words, the intelligence implemented by the control unit 200 relieves the PC of a large number of control and monitoring tasks, and consequently the PC's capacity can be freely utilized for other purposes such as improving overall system manageability and adapting to various clinical and technical conditions. to enhance flexible adaptation.

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The personal computer 300 is used to assist X-ray personnel in selecting the desired mode. A preferred way of providing this assistance is illustrated in FIGS. 4 to 8.

Figure 4 shows a screen image of the personal computer 300 in the first selection mode when body part selection can be made. To the left of the picture is a sketched standing human figure, divided by appropriate demarcation lines into several clearly identifiable sections. One of the areas is blinking. Preferably, the body parts are selected in a predetermined sequence, for example, from head to toe. In Figure 4, the area corresponding to the head flashes. The picture to the right of the human figure shows a caption window. This window lists the X-ray examinations that can be performed on the part of the body that is blinking. If the body part to be selected is not the head, the operator may press one of the standard buttons for controlling up or down on the keyboard of the personal computer 300 to flicker up or down the body part and the contents of the subtitle window will list the exams for the flashing part. When the desired body part is flashing, you can, for example, press the "return" key on the keyboard to validate it. This will cause the selected body part to stop blinking and become more illuminated, and the cursor will jump to the first line of the caption window.

In Figure 5, the selected body part is the chest, which is highlighted, and the caption window shows a list of the chest tests that can be performed. The flashing status of the cursor or the given line can be moved up and down similarly to the selection of a body part, and the selection of the desired test when the corresponding subtitle flashes with the same eg Validated with the return key. As a result of selecting a test, the line for the selected test stops blinking and becomes brighter, just as with selecting a body part. After selection, the kV, mA, and secundum values for the selected test are received from the personal computer 300 in the form of a standard serial information signal to the control unit 200.

We can see that the operating mode outlined here is very easy to master and virtually eliminates the possibility of incorrect settings. The number of body parts that can be selected and the testing options associated with one body part can be varied within wide limits.

The 300 personal computer can provide operators with several other services. The three parameters associated with exposure depend not only on the body part and the desired test, but also on a number of other factors, such as the age and condition of the subject. The condition-specific data may be, for example, body weight, possible pregnancy, or the gypsum state of the body part being examined, etc. There are other factors related to the X-ray equipment. These include, for example, the quality of the film, the distance of the x-ray source from the body part under examination (eg magnification) and the auxiliary equipment eg. a screen presence.

The computer program used to select the body part and the examination is quite simple and can be easily prepared by a person skilled in the art based on the information outlined. A large amount of information should be made available to the 300 PCs. This includes data triplets associated with each optional study. The selection actually defines the memory address on which the desired data set is located. It is understood that as many such tables of data need to be stored in memory as the number of distinguishable (and optional) states.

The condition data should be provided by the operator before or after the selection of body part and test. The status data includes many that are constant for a particular type of device or for a particular position of the device (e.g., film sensitivity, object distance, presence or absence of a grid, etc.), so it is unnecessary to provide it with every shot. Another way to save memory capacity is to compute some of the factors in the knowledge of the data triplets and the steady state data.

The combination of the personal computer 300 with the control unit 200 is a source of several advantages. Above all, it makes the treatment easier and more reliable. In addition, the price of large series PCs is significantly below those of special purpose PCs. As a result of sharing the control function between the computer and the control unit, the computer is freed from performing a large number of special tasks, so programming is possible even without knowing the internal operating conditions and operating conditions of the X-ray equipment, and the PC has sufficient spare capacity to which also allows the development of roaming centers. The overcapacity of a personal computer can be used to record important patient data and automate administrative work, which has so far placed a heavy burden on X-ray staff.

Claims (8)

f. Apparatus for adjusting exposure parameters of an x-ray machine, such as adjusting its high voltage, current and exposure time to meet the requirements of a user-selectable test, wherein the x-ray machine is provided with input terminals receiving electrical parameters for setting the parameters; ), the microcontroller (210) is provided with a interface (211) connected to parallel or serial data lines (70), further comprising a central processing unit (212), random access memory (213), read-only information storing logical states of said signals. memory (214), a timer (215, 216) controlled by instructions from the processor (212), logic state terminals (0) prescribed by the processor (212), said terminals (0), and said input terminals (10, 20, 30, 40). , 50, 60) and a computer (300) for connecting to the interface (211) via a parallel or serial data transmission line (70). The apparatus of claim 1, wherein the X-ray tube (101) has a frequency timer (215) generating a frequency signal associated with data defining anode current, the output of the timer (215) being a frequency voltage forming said coupling circuit. It is connected to an input (231) of a converter (381), its output being connected to a control input of an adjustable power supply (232) whose output is connected to the heating circuit of the X-ray tube (101). Apparatus according to claim 2, characterized in that the heating circuit comprises a current chopper (J07) coupled to the output of the control power supply (232) and a heating transformer (106) having a primary winding connected to its output, the secondary winding (101). connected to the heating element. Apparatus according to claim 2, characterized in that, after the exposure is completed, an output of the processor (212) containing a frequency code corresponding to the preheating between exposures is connected to the timer (215). Apparatus according to any one of claims 1-4, characterized in that the control block (200) comprises a second timer (216) with a timer set at the exposure time required by the personal computer (300), and the output of the second timer (216) is the control block. (200) is connected to an output terminal (0) of a timer which is connected to the input of a timer unit (108) via a timing controller (240). Apparatus according to claim 5, characterized in that it is provided with an exposure button (82) which engages the microcontroller (2t0). 7. Apparatus according to any one of claims 1 to 3, characterized in that the X-ray apparatus (100) comprises a high-voltage transformer (103) which: Equipped with 10 primary windings, the voltage control unit (104) comprises a switching unit (112) coupled to these windings, the actuators of which are connected to relays (113), and a kV control unit (220) is provided as part of the control unit (200). they are connected to the relays (113) and their input is connected to said terminals (0). 8. Apparatus according to any one of claims 1 to 3, characterized in that the control unit (200) is connected to the input terminals (10, 20, 30, 40, 50, 60) of the X-ray apparatus (100) and a plurality of associated auxiliary units (111).