KR101848408B1 - Automatic exposure control apparatus using detector sensor - Google Patents

Abstract

The present invention relates to an automatic exposure control apparatus using a detector sensor. The automatic exposure control apparatus includes a detector sensor part for photographing the X-ray image of a subject, a detector sensor line selection part for selecting at least one specific detector sensor line at a position where the automatic exposure control (AEC) of the detector sensor part is performed, a detector sensor value lead part for reading a value outputted from each detector sensor of the detector sensor line selected at the position where the automatic exposure control is performed, and a control part for reading the specific detector sensor line value and processes it by a predetermined method, and outputting an AEC control signal for interrupting the irradiation of the X-ray when the processed line value is equal to or greater than a preset reference value. It is possible to determine the degree of the X-ray exposure of the X-ray image.

Description

TECHNICAL FIELD [0001] The present invention relates to an automatic exposure control apparatus using a detector sensor,

The present invention relates to an automatic exposure control apparatus using a detector sensor, and more particularly, to a sensor sensor for acquiring an x-ray image, a sensor line for a specific number of sites to be subjected to automatic exposure control, To an automatic exposure control apparatus using a detector sensor, which can determine the degree of X-ray exposure of an X-ray image.

In general, radiation plays an important role in protecting the human body from illness and developing medicine, and it is an essential process for almost every medical imaging examination. With recent advances in science, changes to digital image acquisition systems are rapidly changing the radiation exposure environment.

Such a digital medical environment has the advantage of maximizing user convenience, but in general, the dose of patient exposure may increase in order to reduce image noise and enhance image quality. Thus, medical radiation exposure by radiation is the largest proportion of anthropogenic radiation exposure. Recently, attention has been focused on the management of medical exposure, that is, a method for maximizing diagnostic information while minimizing the dose of radiation with minimal radiation.

On the other hand, in the case of the examination using the diagnosis X-ray, proper conditions should be set and the examination should be carried out with the proper dose. To do this, you need to know the thickness of the subject and the degree of x-ray absorption. However, since it is difficult to be practically applied, a control device that automatically irradiates an appropriate amount of radiation necessary for an image density using an automatic exposure control device (AEC) is widely used.

In particular, since the automatic exposure control apparatus is most frequently used in the chest x-ray inspection, it is not unconditionally reliable. Therefore, the ionization chamber should be accurately positioned at the examination site. If the examination site is not accurately positioned, Can be performed. The ionization chamber is a radiation measuring instrument using ionizing action of gas by radiation.

Currently, there is a method of using the automatic exposure control device (AEC) in which an ion chamber is positioned between a patient and an image detector. In this method, a part of an X-ray radiation signal is reduced There is a problem in that it is inconvenient to replace the existing bucky case with a bucky case which can additionally accommodate the automatic exposure control device (AEC) in order for the automatic exposure control device (AEC) to be usable. Another method of using the automatic exposure control device (AEC) is to place the ion chamber at the rear end of the image detector. In this method, X-ray radiation usable in the ion chamber is detected So that there is a problem that the accuracy of detecting radiation is lowered.

BACKGROUND ART [0002] The background art of the present invention is disclosed in Korean Patent No. 10-1285343 (registered on May 3, 2015, automatic exposure control device).

According to an aspect of the present invention, there is provided an automatic exposure control method for an automatic exposure control system, the automatic exposure control method comprising the steps of: detecting a predetermined number of sensor lines in a detector sensor for acquiring an X- The present invention provides an automatic exposure control apparatus using a detector sensor that can be used as a detection sensor for detecting an X-ray exposure level of an X-ray image.

According to an aspect of the present invention, there is provided an automatic exposure control apparatus using a detector sensor, comprising: a detector sensor section for photographing an X-ray image of a subject; A detector sensor line selector for selecting at least one specific detector sensor line at a position where automatic exposure control (AEC) of the detector sensor unit is to be performed; A detector sensor value lead unit for reading a value output from each detector sensor of a detector sensor line selected in a region where automatic exposure control is to be performed; And a controller for controlling the exposure using the brightness value of the selected detector sensor line value.

In the present invention, the detector sensor is a thin film transistor (TFT) sensor.

In the present invention, the detector sensor line selector includes a gate selector for selecting gates of the detector sensors included in the selected detector sensor line.

In the present invention, the detector sensor value read unit may include a readout integrated circuit (ROIC) that reads an analog signal from a photodiode-based detector sensor and amplifies and outputs the analog signal, And at least one of them is implemented.

In the present invention, the number and position of the specific detector sensor line may be set in advance, or the setting may be changed by a user as required.

In the present invention, the controller may repeatedly read the value of the selected detector sensor line through the detector sensor value read unit while the detector sensor is in the X-ray exposed state.

In the present invention, the controller may be implemented as a Field Programmable Gate Array (FPGA) type or a CPU that performs data storage and calculation by a program command.

In the present invention, when the controller is implemented as an FPGA type, the control unit may include: an accumulator for reading predetermined sensor line values and accumulating them on a line by line basis; A line average value calculation unit for calculating a line average value of the values of the detector sensor lines accumulated through the accumulation unit for each line; A total average value calculation unit for calculating a total average value of the line average values; And a comparison unit comparing the overall average value with a preset brightness value and outputting an AEC control signal for interrupting the irradiation of the X-ray when the overall average value is equal to or greater than the preset brightness value.

In the present invention, when the control unit is implemented as a CPU type, the controller reads the pixel values of the detector sensor line through the detector sensor value read unit during the X-ray exposure state, Calculating a line average value of pixel values of the accumulated detector sensor line, calculating an average value of the line average values, comparing the total average value with a preset brightness value, and comparing the total average value with the preset brightness value And outputs an AEC control signal for interrupting irradiation of the X-ray.

In the present invention, the accumulating unit may include an adder for summing up the pixel values of the detector sensor lines newly read and the pixel values of the corresponding detector sensor lines, which are accumulated and accumulated in the accumulator, and storing them in the accumulator .

In the present invention, the control unit processes the selected sensor line value in a predetermined manner, and outputs an AEC control signal for blocking the irradiation of the X-ray line when the processed line value is equal to or greater than a predetermined value .

According to an aspect of the present invention, there is provided a method for controlling exposure of an X-ray image using a predetermined number of sensor lines of a portion where automatic exposure control is to be performed in a detector sensor for acquiring an X- It is possible to solve the problem that the amount of light is reduced when the conventional ion chamber is used and to provide the automatic exposure control function without any device in an environment where the ion chamber can not be used.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a schematic configuration of an automatic exposure control apparatus using a detector sensor according to an embodiment of the present invention; FIG.
FIG. 2 is an exemplary diagram showing a schematic configuration of a control unit in FIG. 1; FIG.
3 is a flowchart for explaining a control unit in FIG.

Hereinafter, an embodiment of an automatic exposure control apparatus using a detector sensor according to the present invention will be described with reference to the accompanying drawings.

In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

FIG. 1 is a schematic view illustrating an automatic exposure control apparatus using a detector sensor according to an embodiment of the present invention. Referring to FIG.

1, the automatic exposure control apparatus using the detector sensor according to the present embodiment includes a detector sensor unit 100, a detector sensor value lead unit 400, a detector sensor line selection unit 500, (600).

The detector sensor unit 100 provides digital image information of a subject photographed with an X-ray, and may be referred to as a thin film transistor (TFT) detector.

For example, the detec- tor sensor unit 100 is a digital image detection sensor that functions as a film in a conventional analog X-ray imaging apparatus, and allows an X-ray imaging apparatus to confirm an X-ray image immediately after being taken by a digital X-ray imaging apparatus using a computer monitor.

The detector sensor line selection unit 500 selects at least one specific line (i.e., a horizontal line or a vertical line) in the detector sensor unit 100 of the region of interest (ROI) (Or TFT detectors) 200, 201, and 202 and may include at least one or more gate selectors 501 to 505 for selecting gates of the detector sensors (or TFT detectors).

The detector sensor value read unit 400 selectively reads a value output from a detector sensor (or a TFT detector) of a part 300 where automatic exposure control is to be performed.

For example, the detector sensor value read unit 400 performs a function of a readout integrated circuit (ROIC) that reads an analog signal from a photodiode-based detector sensor, and amplifies and outputs the analog signal.

Therefore, the detector sensor value lead unit 400 includes at least one ROIC 401 to 405 corresponding to the size of the part 300 to be subjected to the automatic exposure control.

The controller 600 controls the detector sensor line selector 500 to select at least one specific line 200, 201, or 202 of the detector sensor of the part 300 where automatic exposure control is to be performed, And controls the detector sensor value read unit 400 to selectively read a value output from a detector sensor (or a TFT detector) of a part 300 where automatic exposure control is to be performed.

For example, the controller 600 may select at least one detector sensor line (row line) through the detector sensor line selector 500 in a region 300 where automatic exposure control is to be performed, It is used as a sensor.

Here, the number of the parts 300 and the detector sensor line (Row Line) to be subjected to the automatic exposure control may be set in advance, and the setting may be changed by the user as necessary.

The controller 600 repeatedly reads the value of the detector sensor line through the detector sensor value read unit 400 at least twice at a high speed while the detector sensor unit 100 is in the X-ray exposure state. Of course, depending on the setting, the detector sensor line may repeatedly read the value of the detector sensor line through the detector sensor value read unit 400 at a high speed while the detector sensor unit 100 is in the X-ray exposure state. That is, there is no restriction on the number of times the sensor line value is read.

The control unit 600 may be implemented as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and may include designable logic elements such as AND, OR, XOR, Decoders, logic gates, etc.) and programmable internal lines (e.g., logic blocks, flip-flops, memory, etc.). Also, the controller 600 may be implemented as a CPU that performs data storage and calculation by program instructions, and does not limit the implementation medium.

The control unit 600 reads values (e.g., image brightness levels) of the detector sensor lines through the detector sensor value reading unit 400, accumulates the values on a line-by-line basis, (For example, image brightness level), and then calculates the average value of the line average values.

In calculating the total average value, the maximum and minimum mean values may be removed and an average may be calculated to reduce the deviation of the average values. For example, in calculating the average value, it is possible to simply obtain the average of all the values, and to assign the weight to each pixel value to obtain the average value, and the calculation method of the average value is not limited. Here, the line average value means an ROI (region of interest), that is, a brightness average value of a portion 300 to be subjected to automatic exposure control in FIG.

Next, the entire average value (i.e., the average image brightness level) is compared with a predetermined brightness value (a kind of reference value), and if the total average value (i.e., average image brightness level) is equal to or greater than the predetermined brightness value, .

FIG. 2 is an exemplary diagram showing a schematic configuration of a control unit in FIG. 1; FIG.

2, the controller 600 includes accumulators 610 and 620 for reading predetermined sensor sensor line values (e.g., image brightness levels) and accumulating them on a line-by-line basis, Line average value calculating units 630 and 631 for calculating a line average value of the values of the detector sensor lines accumulated (for example, image brightness levels) through the line sensor units 610 and 620, a total average value calculating unit (650) for comparing the total average value (i.e., the average image brightness level) with a predetermined brightness value and outputting an AEC control signal for blocking the irradiation of the X-ray when the total average value is equal to or greater than the predetermined brightness value ).

Meanwhile, the accumulators 610 and 620 accumulate the values of the detector sensor line values (pixel values) newly input (input) and the pixel values of the corresponding detector sensor lines, which are accumulated and accumulated in the accumulators 612 and 622, And accumulators (612, 622) for storing the signals in the accumulators (612, 622).

The line average value calculators 630 and 631 calculate an average value (i.e., a line average value) of detector sensor line values (e.g., image brightness levels) (e.g., image brightness levels) output from the accumulators 610 and 620, .

The overall average value calculating unit 640 calculates the total average value of the detector sensor line values (e.g., image brightness level) output from the line average value calculating units 630 and 631 (i.e., the total line average value). For example, in calculating the average value, it is possible to simply obtain the average of all the values, and to assign the weight to each pixel value to obtain the average value, and the calculation method of the average value is not limited. In calculating the total average value, the maximum and minimum mean values may be removed and an average may be calculated to reduce the deviation of the average values. That is, the overall average may be calculated by transforming the average values in the calculation of the total average value, selecting a partial average value according to the designated condition, or selecting and excluding a partial average value according to the predetermined condition.

The comparator 650 compares a total average value (i.e., a total line average value) of each detector sensor line value output from the total average value calculator 640 with a predetermined brightness value (a kind of reference value) And outputs an AEC control signal for blocking the irradiation of the X-ray when the total average value is equal to or greater than the preset brightness value.

3 is a flowchart for explaining the control unit in FIG.

As shown in FIG. 3, when the controller 600 is in the X-ray exposure state (YES in S101), the control unit 600 reads each preset detector sensor line value (pixel value) (S102) The detector sensor line values (pixel values) are accumulated (S103).

Next, the controller 600 calculates an average value (i.e., a line average value) of the accumulated detector sensor line values (e.g., image brightness levels) (S104).

Next, the controller 600 calculates a total average value (i.e., a total line average value) of the calculated detector sensor line values (e.g., image brightness level) (S105). In calculating the total average value, the maximum and minimum mean values may be removed and an average may be calculated to reduce the deviation of the average values.

Next, the controller 600 compares the total average value (i.e., the total line average value) of the calculated detector sensor line values with a preset brightness value (a kind of reference value) (S106) If it is equal to or greater than the preset brightness value (YES in S107), the AEC control signal for cutting off the irradiation of the X-ray is outputted (S108).

However, if the overall average value is not equal to or greater than the preset brightness value (NO in S107), the overall average value calculation process (S102 to S107) may be repeatedly performed.

As described above, in the present embodiment, the detector sensor for acquiring the x-ray image can determine the degree of x-ray exposure of the x-ray image by using a specific number of sensor lines of the part where automatic exposure control is to be performed as a sensor for automatic exposure control Thus, it is possible to solve the problem that the amount of light is reduced when the conventional ion chamber is used, and it is possible to provide an automatic exposure control function without an additional device in an environment where the ion chamber can not be used.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, I will understand the point. Accordingly, the technical scope of the present invention should be defined by the following claims.

100: Detector sensor section
200, 201, 202: Line for use as AEC sensor
300: The part you want to use as a sensor to perform the AEC
400, 401 to 405: Detector sensor value lead portion
500, 501 to 505: Detector sensor line selector
600:
610, 620:
611, 621: adder
612, 622: accumulator
630, 631: line average value calculating section
640: total average value calculating unit
650:

Claims (9)

A detector sensor unit for photographing an X-ray image of a subject;
A detector sensor line selector for selecting at least one specific detector sensor line at a position where automatic exposure control (AEC) of the detector sensor unit is to be performed;
A detector sensor value lead unit for reading a value output from each detector sensor of a detector sensor line selected at a position where the automatic exposure control is to be performed; And
And a controller for controlling the exposure using the brightness value of the selected detector sensor line value,
Wherein the detector sensor value lead portion comprises:
A readout integrated circuit (ROIC) for reading an analog signal from a photodiode-based detector sensor and amplifying and outputting the analog signal is provided including at least one corresponding to a size of a portion to be subjected to the automatic exposure control,
Wherein,
An accumulator for reading predetermined detector sensor line values and accumulating them on a line by line basis; A line average value calculation unit for calculating a line average value of the values of the detector sensor lines accumulated through the accumulation unit for each line; A total average value calculation unit for calculating a total average value of the line average values; And a comparator for comparing the total average value with a preset brightness value and outputting an AEC control signal for interrupting the irradiation of the X-ray when the total average value is equal to or greater than the predetermined brightness value. Exposure control device.
The apparatus according to claim 1,
Wherein the sensor is a thin film transistor (TFT) sensor.
The apparatus of claim 1, wherein the detector sensor line selector comprises:
And a gate selector for selecting a gate of each of the detector sensors included in the selected detector sensor line.
delete The method of claim 1, wherein the specific detector sensor line comprises:
The number and position of which can be set in advance or the setting can be changed by the user.
The apparatus of claim 1,
Wherein the controller repeatedly reads the value of the selected detector sensor line through the detector sensor value read unit while the detector sensor is in the X-ray exposed state.
The apparatus of claim 1,
A field programmable gate array (FPGA) type,
(CPU) that stores and computes data according to a program command.
delete The apparatus of claim 1,
And outputs an AEC control signal for blocking the irradiation of the X-ray when the processed line value is equal to or greater than a preset value. The apparatus according to claim 1, controller.

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