WO2018080195A1

WO2018080195A1 - Automatic x-ray exposure control method using time synchronization in wireless environment

Info

Publication number: WO2018080195A1
Application number: PCT/KR2017/011908
Authority: WO
Inventors: 홍승기; 김용진
Original assignee: 주식회사 뷰웍스
Priority date: 2016-10-28
Filing date: 2017-10-26
Publication date: 2018-05-03
Also published as: KR20180046939A

Abstract

The present invention relates to an automatic X-ray exposure control method using time synchronization in a wireless environment, comprising the steps of: allowing a wireless detector to synchronize time with a system control device; allowing the wireless detector to wirelessly transmit, to the system control device, X-ray exposure information calculated during X-ray imaging; allowing the system control device to calculate an X-ray exposure limit time point by using the X-ray exposure information wirelessly transmitted from the wireless detector; and allowing the system control device to transmit, to a generator, an AEC signal for stopping X-ray radiation when the present time point becomes the X-ray exposure limit time point.

Description

X-ray automatic exposure control using time synchronization in wireless environment

The present invention relates to an X-ray automatic exposure control method using time synchronization in a wireless environment. More particularly, in an X-ray imaging system for acquiring an X-ray image with a wireless detector, X-ray automatic exposure control can be stably performed in a wireless manner. It's about technology that makes it possible.

In general, radiation plays an important role in the protection of the human body from disease and in the development of medicine and is an essential process for almost all medical imaging tests. Recently, with the development of science, the change to the digital image acquisition device is rapidly changing the radiation exposure environment.

Such a digital medical environment has an advantage of maximizing user convenience, but in general, the dose of the patient may be increased to reduce image noise and improve image quality. As such, medical exposure by radiation accounts for the largest proportion of artificial radiation exposure. Recently, attention has been focused on medical exposure management, that is, a method for maximizing diagnostic information while reducing exposure dose with minimal radiation.

On the other hand, in the case of a test using diagnostic X-rays, an appropriate dose should be set by setting appropriate conditions. To do this, it is necessary to know the thickness and X-ray absorption degree according to the subject. However, since it is difficult to apply in reality, a control device that automatically irradiates an appropriate amount of radiation required for the concentration of the image using an automatic exposure control (AEC) device is widely used.

The automatic exposure control (AEC) should be able to determine the degree of X-ray exposure in real time during X-ray imaging and stop X-ray irradiation at the correct time.

Accordingly, conventionally, a control signal for automatic exposure control (AEC) between a detector (i.e., a sensor for detecting a kind of X-ray image) and a generator (i.e., a device for irradiating X-rays) (e.g., X-rays when the X-ray exposure is above a specified value) The line for outputting the AEC control signal, which is output to block the irradiation of, was connected in a wired manner.

However, in the case of an X-ray imaging system that acquires an X-ray image with a wireless detector, since the system control apparatus needs to collect X-ray exposure information wirelessly from the wireless detector and perform automatic exposure control (AEC), the operation state of the X-ray imaging system or According to the surrounding environment, there is a problem that a situation in which accurate automatic exposure control (AEC) cannot be performed may occur.

Background art of the present invention is disclosed in Republic of Korea Patent Publication No. 10-2015-0040768 (2015.04.15. Publication, X-ray apparatus and X-ray detector).

According to an aspect of the present invention, the present invention was created to solve the above problems, in the X-ray imaging system for acquiring an X-ray image with a wireless detector, time synchronization between the wireless detector and the system control device An object of the present invention is to provide an X-ray automatic exposure control method using time synchronization in a wireless environment.

X-ray automatic exposure control method using time synchronization according to an aspect of the present invention, the wireless detector and the system control apparatus of the X-ray imaging system for acquiring the X-ray image in a method for performing X-ray automatic exposure control through time synchronization in a wireless environment The wireless detector comprising: time synchronization with the system control apparatus; Wirelessly transmitting, by the wireless detector, the X-ray exposure information calculated during X-ray imaging to the system control apparatus; Calculating, by the system control apparatus, an X-ray exposure limit time point using X-ray exposure information wirelessly transmitted from the wireless detector; And when the current time point becomes the X-ray exposure limit time point, transmitting, by the system control apparatus, an AEC control signal for stopping X-ray irradiation to the generator.

In the present invention, in the step of synchronizing the time, the wireless detector generates and transmits a time synchronization packet having a predetermined format to the system control apparatus, and the system control apparatus transmits the time synchronization packet transmitted from the wireless detector. After receiving, the time synchronization packet is transmitted to the wireless detector again, and the wireless detector generates a time synchronization packet received completion packet immediately after receiving the time synchronization packet transmitted from the system control apparatus, and the system control apparatus. And the system control device receives the time synchronization packet reception completion packet to complete time synchronization.

In the present invention, the time synchronization packet and the time synchronization packet reception completed packet may be recorded with at least one of transmission time and reception time of the corresponding packet.

In the present invention, in the step of synchronizing the time, the wireless detector and the system control unit perform synchronization at a time interval of 1 ms or 1 ms, and are smaller than when a more accurate X-ray exposure limit point is to be calculated. The synchronization is performed on a time basis.

In the present invention, in the step of wirelessly transmitting the X-ray exposure information, when the X-ray image recording starts after the time synchronization is completed, the wireless detector checks whether the X-ray exposure information calculation period, the specified X-ray exposure information calculation period When the X-ray exposure information is calculated, and the calculation of the X-ray exposure information is completed, the wireless detector transmits the calculated X-ray exposure information to the system control device, and until the X-ray imaging is completed, according to the specified period. The wireless detector repeats the process of calculating and transmitting the X-ray exposure information to the system control apparatus.

In the transmitting of the AEC control signal, the system control apparatus receives the X-ray exposure information as the wireless detector calculates and transmits the X-ray exposure information at the designated period, and receives the received X-ray exposure information. After calculating the X-ray exposure limit time point on the time axis based on the X-ray exposure information, it is checked whether the current time point is the calculated X-ray exposure limit time point, and if it is determined that the current time point is the X-ray exposure limit time point, the generator generates an AEC control signal. It characterized in that to stop the X-ray irradiation by transmitting.

In the present invention, in calculating the X-ray exposure limit time point on the time axis, the X-ray exposure limit time point is calculated by summing the dose amounts that change over time based on the dose change graph corresponding to the generator type. .

In the present invention, the X-ray exposure information is internally calculated by the wireless detector itself and wirelessly transmitted, or by receiving the X-ray exposure information calculated by a separate means including an ion chamber, the wireless detector wirelessly transmits. It is done.

According to an aspect of the present invention, in the X-ray imaging system for acquiring an X-ray image with a wireless detector, by allowing time synchronization between the wireless detector and the system control device, X-ray automatic exposure control also in a wireless manner To ensure stable operation.

1 is an exemplary view showing a schematic configuration of an X-ray imaging system including a wireless detector according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a schematic configuration of a wireless detector in FIG. 1.

3 is an exemplary view showing a schematic configuration of a system control apparatus in FIG.

4 is a flowchart illustrating a time synchronization method for automatic exposure control according to an embodiment of the present invention.

5 is a flowchart illustrating an operation of a wireless detector in an X-ray imaging system according to an embodiment of the present invention.

6 is a flowchart illustrating the operation of the system control apparatus in the X-ray imaging system according to an embodiment of the present invention.

7 is an exemplary view showing a graph for predicting the X-ray exposure limit time by the system control apparatus in the X-ray imaging system according to an embodiment of the present invention.

Hereinafter, an embodiment of an X-ray automatic exposure control method using time synchronization in a wireless environment according to the present invention will be described with reference to the accompanying drawings.

In this process, the thickness of the lines or the size of the components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to the intention or convention of a user or an operator. Therefore, the definitions of these terms should be made based on the contents throughout the specification.

As shown in FIG. 1, the X-ray imaging system according to an exemplary embodiment of the present invention includes a wireless detector 100, a system control apparatus 200, a server 300, and a generator 400.

The generator 400 radiates X-rays to the wireless detector 100.

The generator 400 and the system control device 200 are connected in a wired manner to transmit and receive a control signal (eg, an AEC control signal) (that is, the system control device 200 transmits an AEC control signal and generates a generator ( 400) receives an AEC control signal).

In addition, the generator 400 stops X-ray irradiation when an AEC control signal is received from the system control apparatus 200 (or may be referred to as a controller).

In addition, the system control apparatus 200 may be configured as part of the generator 400.

The wireless detector 100 acquires an X-ray image radiated from the generator 400.

In addition, the wireless detector 100 and the system control apparatus 200 are connected in a wireless manner, and the wireless detector 100 calculates X-ray exposure information and transmits the X-ray exposure information to the system control apparatus 200.

In addition, the wireless detector 100 performs time synchronization to transmit the X-ray exposure information to the system control apparatus 200.

In addition, the wireless detector 100 is wirelessly connected to the system control apparatus 200 to transmit and receive image data, X-ray exposure information, and at least one control signal (eg, a time synchronization signal or a packet).

Meanwhile, the system control apparatus 200 receives time X-ray exposure information from the wireless detector 100 after performing time synchronization with the wireless detector 100.

In addition, the system control apparatus 200 calculates (or predicts) an X-ray exposure limit time point on the time axis, and when the X-ray exposure information reaches the calculated X-ray exposure limit time point, a control signal (ie, AEC control signal) is transmitted (or transmitted).

In this case, the system control apparatus 200 may refer to a graph as shown in FIG. 7 to calculate (or predict) the X-ray exposure limit time point.

7 is an exemplary view illustrating a graph for predicting an X-ray exposure limit time by a system control apparatus in an X-ray imaging system according to an exemplary embodiment of the present invention.

That is, the system control apparatus 200 refers to the dose rate that changes with time, even if the X-ray exposure information is not received through the wireless detector 100 temporarily, but the wireless detector ( Since the time synchronization between the system 100 and the system control device 200 is achieved, when the X-ray exposure limit time is reached by the calculation (or prediction), a control signal (ie, AEC control) is transmitted to the generator 400. Signal) is transmitted (or transmitted).

As described above, the system control apparatus 200 according to the present exemplary embodiment may expose X-rays through the time synchronization even if the reliability of wireless communication is deteriorated according to the operating state of the X-ray imaging system using the wireless detector 100 or the surrounding environment. By accurately calculating (or predicting) the time to reach the threshold time point and outputting a control signal (AEC control signal), it is possible to perform accurate automatic exposure control (AEC).

Meanwhile, the server 300 (or workstation), which is not described in FIG. 1, communicates with the system control apparatus 200 to perform overall operation of the X-ray imaging system. For example, the server 300 (or workstation) may change a setting of the wireless detector 100 or receive an image acquired by the wireless detector 100 through the system control apparatus 200.

FIG. 2 is an exemplary view showing a schematic configuration of a wireless detector in FIG. 1, and FIG. 3 is an exemplary diagram showing a schematic configuration of a system control apparatus in FIG. 1.

As shown in FIG. 2, the wireless detector 100 includes an X-ray exposure information calculator 110, an X-ray exposure information transmitter 120, and a time synchronizer 130.

The X-ray exposure information calculator 110 calculates X-ray exposure information in the wireless detector 100.

The X-ray exposure information transmitter 110 transmits (or transmits) the calculated X-ray exposure information to the system control apparatus 200.

The time synchronization unit 130 transmits and receives a time synchronization packet with the system control apparatus 200 to perform time synchronization with each other. In this case, the time synchronization packet includes a transmission time of a packet for time synchronization, a transmission period (transmission interval), and the like.

Although not specifically illustrated in the drawing, the X-ray exposure information may be calculated through other components (eg, an ion chamber, etc.) (not shown) of the X-ray imaging system. That is, the wireless detector 100 does not include the X-ray exposure information calculator 110, but instead receives X-ray exposure information calculated in the ion chamber (not shown), and then transfers the received X-ray exposure information. The X-ray exposure information transmitter 110 may transmit (or transmit) the data to the system control apparatus 200. In other words, the wireless detector 100 does not necessarily have to perform calculation of X-ray exposure information, and performs only a function of receiving and transmitting X-ray exposure information from another component (eg, an ion chamber, etc.) (not shown). It may be.

As illustrated in FIG. 3, the system control apparatus 200 may include an X-ray exposure information receiver 210, an X-ray exposure limit time calculator 220, a time synchronizer 230, and an AEC control signal transmitter 240. Include.

The X-ray exposure information receiver 210 receives X-ray exposure information transmitted (or transmitted) from the wireless detector 100.

The X-ray exposure limit point calculator 220 calculates an X-ray exposure limit point to derive a point in time when the X-ray exposure reaches a limit.

The reason for deriving the X-ray exposure limit point is that X-ray exposure information transmitted and received between the wireless detector 100 and the system control apparatus 200 is transmitted and received in a wireless manner, so that the X-rays are exposed at regular intervals in the wireless detector 100. Even if the exposure information is transmitted, the system control apparatus 200 that receives the exposure information may receive X-ray exposure information at irregular times, and the wireless detector 100 and the system control apparatus 200 may receive the exposure information. This is because the X-ray exposure limit time may be reached while X-ray exposure information is transmitted and received between the two.

The time synchronization unit 230 transmits and receives a time synchronization packet with the wireless detector 100 to perform time synchronization with each other. In this case, the time synchronization packet includes a transmission time of a packet for time synchronization, a transmission period (transmission interval), and the like.

As illustrated in FIG. 7, the AEC control signal transmitter 240 temporarily receives X-ray exposure information through the wireless detector 100 with reference to a dose rate that varies with time. If not, when the X-ray exposure limit time is reached by the calculation (or prediction), a control signal (ie, an AEC control signal) is transmitted (or transmitted) to the generator 400.

4 is a flowchart illustrating a time synchronization method for automatic exposure control according to an embodiment of the present invention. Referring to FIG. 4, time synchronization is performed between the wireless detector 100 and the system control apparatus 200. How to do this is explained.

As shown in FIG. 4, the wireless detector 100 generates and transmits a time synchronization packet having a predetermined format to the system control apparatus 200 (S101).

After receiving the time synchronization packet transmitted from the wireless detector 100 (S102), the system control apparatus 200 transmits the time synchronization packet to the wireless detector 100 again (S103).

After receiving the time synchronization packet transmitted from the system control apparatus 200, the wireless detector 100 immediately generates a time synchronization packet reception completion packet and transmits it to the system control apparatus 200 (S104).

Accordingly, the system control apparatus 200 completes time synchronization after receiving the time synchronization packet reception completion packet (S105).

At this time, the transmission time (or reception time) of the packet is recorded in each packet (eg, time synchronization packet, time synchronization packet reception completion packet). Therefore, the system control apparatus 200 completes time synchronization based on the wireless detector 100.

For reference, in synchronizing the time between the wireless detector 100 and the system control apparatus 200, the time between the wireless detector 100 and the system control apparatus 200 may be set to a time unit such as 1 ms or 1 ms. It can also be synchronized in smaller time units to calculate (predict) more accurate X-ray exposure thresholds.

Next, when the time synchronization is completed between the wireless detector 100 and the system control apparatus 200 as described above, as shown in FIGS. 5 and 6, the system control apparatus 200 performs automatic exposure control (AEC). Perform

As shown in FIG. 5, when the X-ray imaging starts after the time synchronization is completed, the wireless detector 100 checks whether the X-ray exposure information calculation cycle is performed (S201), and if it is the specified X-ray exposure information calculation cycle (S201). Example), X-ray exposure information is calculated (S202).

When the calculation of the X-ray exposure information is completed as described above, the wireless detector 100 transmits the calculated X-ray exposure information to the system control apparatus 200 (S203).

The steps S201 to S203 of calculating the X-ray exposure information and transmitting the X-ray exposure information to the system control apparatus 200 according to the specified cycle as described above are repeatedly performed until the X-ray imaging is completed. (Example of S204).

However, the period for calculating the X-ray exposure information does not have to be specified in advance, and in some embodiments, the X-ray exposure information may be calculated and transmitted to the system control apparatus 200 aperiodically.

As the wireless detector 100 calculates the X-ray exposure information and transmits the X-ray exposure information to the system control apparatus 200 in the designated period as described above, the system control apparatus 200 receives the X-ray exposure information (S301).

However, even if the wireless detector 100 transmits the X-ray exposure information at a designated period, the system control apparatus 200 may not necessarily receive the X-ray exposure information at a specified period, even if the wireless detector 100 transmits the X-ray exposure information. For example, the X-ray exposure information may be delayed or received or missed.

The system control apparatus 200 calculates (predicts) an X-ray exposure limit time point on a time axis based on the received X-ray exposure information (S302).

For example, FIG. 7 is a graph of directly measuring dose variation when radiographing is performed using a designated generator 400 under a dose condition of 100 kVp 100 mA 100 ms. From it can be seen that the dose per hour is constant. Therefore, from 20ms onwards, it is possible to predict the dose amount accumulated over time, and thus to predict the X-ray exposure limit time point of the image.

That is, the system control apparatus 200 is based on the dose change graph in the predetermined condition of the generator 400, the elapsed time from the time after the dose amount is constant to the dose amount accumulated in the period in which the dose amount increases per hour. Correspondingly, the cumulative dose amount may be added to calculate (or predict) an X-ray exposure limit time point.

However, the dose change amount per hour may vary depending on the type and setting of the generator 400. Therefore, the dose change graph per hour may be generated by the system control apparatus 200 based on the X-ray exposure information received from the wireless detector 100, and may be generated and used as a mathematical expression even if the graph is not in the form of a graph. Alternatively, the system control apparatus 200 may download an hourly dose change graph (or equation) or setting corresponding to the type of the generator 400 from the server 300 in advance (that is, calculate the X-ray exposure limit time point). Or for prediction).

When the X-ray exposure limit point is calculated (predicted) as described above, the system control apparatus 200 checks whether or not the X-ray exposure limit point (S303), and when it is determined that the current X-ray exposure limit point (S303). The AEC control signal is transmitted to the generator 400 to stop X-ray irradiation (S304).

As described above, in the present embodiment, the wireless detector 100 transmits the X-ray exposure information of the image to the system control apparatus 200 at a predetermined cycle, so that the system control apparatus 200 may predict the X-ray exposure limit time point of the image. Even if the X-ray exposure information is not normally transmitted due to the characteristics of the wireless system, the X-ray irradiation may be stopped by transmitting an AEC control signal to the generator 400 at the X-ray exposure limit time predicted by the system control apparatus 200. By doing so, there is an effect to provide an accurate and stable automatic exposure control (AEC) function in a wireless environment.

Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely exemplary, and various modifications and equivalent other embodiments are possible for those skilled in the art to which the art pertains. I will understand the point. Therefore, the technical protection scope of the present invention will be defined by the claims below.

Claims

A method of performing X-ray automatic exposure control through time synchronization in a wireless environment by a wireless detector and a system controller of an X-ray imaging system acquiring an X-ray image,

The wireless detector performing time synchronization with the system control apparatus;

Wirelessly transmitting, by the wireless detector, the X-ray exposure information calculated during X-ray imaging to the system control apparatus;

Calculating, by the system control apparatus, an X-ray exposure limit time point using X-ray exposure information wirelessly transmitted from the wireless detector; And

And transmitting, by the system control apparatus, an AEC control signal for stopping X-ray irradiation to a generator when a current time point becomes the X-ray exposure limit time point. Control method.
The method of claim 1, wherein in the time synchronization:

The wireless detector generates and transmits a time synchronization packet of a predetermined format to the system control apparatus.

The system controller receives the time synchronization packet transmitted from the wireless detector, and then transmits the time synchronization packet to the wireless detector again.

After receiving the time synchronization packet transmitted from the system control device, the wireless detector generates a time synchronization packet reception completion packet and transmits it to the system control device immediately.

The apparatus for controlling automatic exposure of X-rays using time synchronization in a wireless environment, characterized in that the system control device receives the time synchronization packet reception completion packet and completes time synchronization.
The method of claim 2,

The time synchronization packet and the time synchronization packet received completion packet,

At least one of the transmission time or the reception time of the packet is recorded X-ray automatic exposure control method using time synchronization in a wireless environment.
The method of claim 1, wherein in the time synchronization:

The wireless detector and the system control device,

X-ray automatic exposure control method using a time synchronization in a wireless environment, characterized in that for performing the synchronization in units of 1 ms or 1 ms.
The method of claim 1, wherein wirelessly transmitting the X-ray exposure information.

The wireless detector,

After the time synchronization is completed, the X-ray image recording starts, checks whether the X-ray exposure information calculation cycle, calculates the X-ray exposure information at the specified X-ray exposure information calculation cycle,

When the calculation of the X-ray exposure information is completed, the wireless detector transmits the calculated X-ray exposure information to the system control device.

Until the X-ray photographing is completed, the X-ray automatic operation using time synchronization in a wireless environment, characterized in that the wireless detector repeats the step of calculating the X-ray exposure information and transmits the X-ray exposure information to the system control apparatus according to the specified period. Exposure control method.
The method of claim 1, wherein in the step of transmitting the AEC control signal,

The system control device,

Receiving the X-ray exposure information as the wireless detector calculates and transmits the X-ray exposure information in the designated period,

After calculating the X-ray exposure limit time point on the time axis based on the received X-ray exposure information, it is checked whether the current time point is the calculated X-ray exposure limit time point,

If it is determined that the current time point is the X-ray exposure limit time, X-ray automatic exposure control method using time synchronization in a wireless environment, characterized in that the X-ray irradiation is stopped by transmitting an AEC control signal to the generator.
The method of claim 6,

In calculating the X-ray exposure limit time point in the time axis,

The X-ray automatic exposure control method using time synchronization in a wireless environment, characterized in that for calculating the X-ray exposure limit time point by summing the dose changes per hour based on the dose change corresponding to the type of the generator.
The method of claim 1, wherein the X-ray exposure information,

Internally calculated by the wireless detector itself, the wireless transmission,

The X-ray automatic exposure control method using time synchronization in a wireless environment, characterized in that the wireless detector wirelessly receives the X-ray exposure information calculated by a separate means including an ion chamber.