阅读说明：本技术 一种ct系统中射线剂量的控制方法及系统 (Control method and system for ray dose in CT system ) 是由 王青强 于 2019-12-27 设计创作，主要内容包括：本发明提出一种CT系统中射线剂量的控制方法及系统,本发明预先构建了被检查者体重与驱动器输出电流之间的关系式；然后在CT检查过程中读取驱动器的输出电流,并根据被检查者体重与驱动器输出电流之间的关系式转换成被检查者的等效体重；最后,根据计算出的被检查者等效体重值,在不同的扫描位置动态调整射线剂量,使得扫描图像更清晰,病人受到的射线更小更合理。(The invention provides a control method and a system of ray dose in a CT system, which pre-construct a relational expression between the weight of a checked person and the output current of a driver; then reading the output current of the driver in the CT examination process, and converting the output current into the equivalent weight of the examined person according to the relational expression between the weight of the examined person and the output current of the driver; finally, according to the calculated equivalent weight value of the examined person, the ray dosage is dynamically adjusted at different scanning positions, so that the scanned image is clearer, and the ray received by the patient is smaller and more reasonable.)

1. A control method of ray dose in a CT system is characterized in that the CT system comprises an examination bed, a driver and a driving motor, wherein the driving motor drives the examination bed to horizontally move according to pulses output by the driver;

the control method comprises the following steps:

(1) constructing a relation between the equivalent weight of the examined person and the output current of the driver:

wherein m represents the equivalent weight of the examinee, U represents the rated voltage of the driver, I represents the output current of the driver, R represents the driving radius of the driving motor, n represents the rotating speed of the motor, g represents the gravity acceleration, and mu represents the friction coefficient when the examination bed moves;

(2) in the checking process, when the checking bed moves at a constant speed, reading driver parameters including rated voltage and output current, and reading the rotating speed of a driving motor; then, according to the formula

2. A system for controlling radiation dose in a CT system, comprising: the device comprises an examination bed, an examination bed control board, a driver, a driving motor and a workstation; wherein the content of the first and second substances,

the examination bed control panel provides a user interaction window and generates a control signal of the driver according to the motion control parameters of the examination bed input by a user; reading the driver parameters and the rotating speed of the driving motor, calculating the equivalent weight of the checked person according to the read data and sending the equivalent weight to the workstation; the formula for calculating the equivalent weight of the examinee is as follows:

wherein, U represents the rated voltage of the driver, I represents the output current of the driver, R represents the driving radius of the driving motor, n represents the rotating speed of the motor, g represents the gravity acceleration, and mu represents the friction coefficient when the examination bed moves;

the driver generates a pulse waveform according to a control signal sent by the control panel of the examination bed, outputs the pulse waveform to the driving motor, and controls the driving motor to rotate so as to drive the examination bed to horizontally move;

the workstation receives the weight value of the examinee sent by the control panel of the examination bed and adjusts the radiation dose in the scanning process according to the weight value.

3. A radiation dose control system in CT system as claimed in claim 2, wherein said table control board acquires the rotation speed of the driving motor through the electronic encoder.

4. A radiation dose control system in a CT system as claimed in claim 2, wherein said table control board reads parameters of the driver via CANOPEN protocol, said parameters comprising: rated voltage, output current.

5. The system of claim 2, wherein the table control board interacts data with the workstation via a custom CAN bus protocol.

Technical Field

The invention relates to the technical field of CT scanning, in particular to a method and a system for controlling ray dose in a CT system.

Background

CT is electronic computerized tomography, which uses precisely collimated X-ray beam and detector with high sensitivity to scan the cross section of human body one by one. The CT mainly comprises a frame, an examination table and a workstation. Normally, by performing a scanning operation on the CT device in the shielding room at the workstation, an operator may select different scanning modes according to different parts to be scanned, the different scanning modes may have different dose outputs, and the quality of the image is closely related to the dose of the scanning. However, the existing scanning technology has certain defects that the dosage can be adjusted only according to different parts, and for inspectors with different weights, a workstation cannot automatically control the scanning dosage according to the weight of the inspectors.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects of the prior art, the invention provides a method and a system for controlling the ray dose in a CT system, which can realize that different equivalent weight values are obtained according to different body positions of a patient in the CT scanning process, and further adjust the ray dose.

The technical scheme is as follows: in order to achieve the purpose, the technical scheme provided by the invention is as follows:

a control method of ray dose in a CT system comprises an examination bed, a driver and a driving motor, wherein the driving motor drives the examination bed to horizontally move according to pulses output by the driver;

the control method comprises the following steps:

(1) constructing a relation between the equivalent weight of the examined person and the output current of the driver:

wherein m represents the equivalent weight of the examinee, U represents the rated voltage of the driver, I represents the output current of the driver, R represents the driving radius of the driving motor, n represents the rotating speed of the motor, g represents the gravity acceleration, and mu represents the friction coefficient when the examination bed moves;

(2) in the checking process, when the checking bed moves at a constant speed, reading driver parameters including rated voltage and output current, and reading the rotating speed of a driving motor; then, according to the formula

Calculating the equivalent weight of the current examinee, and then adjusting the radiation dose according to the calculated m.

The invention also provides a radiation dose control system in a CT system, which comprises: the device comprises an examination bed, an examination bed control board, a driver, a driving motor and a workstation; wherein the content of the first and second substances,

the examination bed control panel provides a user interaction window and generates a control signal of the driver according to the motion control parameters of the examination bed input by a user; reading the driver parameters and the rotating speed of the driving motor, calculating the equivalent weight of the checked person according to the read data and sending the equivalent weight to the workstation; the formula for calculating the equivalent weight of the examinee is as follows:

wherein, U represents the rated voltage of the driver, I represents the output current of the driver, R represents the driving radius of the driving motor, n represents the rotating speed of the motor, g represents the gravity acceleration, and mu represents the friction coefficient when the examination bed moves;

the driver generates a pulse waveform according to a control signal sent by the control panel of the examination bed, outputs the pulse waveform to the driving motor, and controls the driving motor to rotate so as to drive the examination bed to horizontally move;

the workstation receives the weight value of the examinee sent by the control panel of the examination bed and adjusts the radiation dose in the scanning process according to the weight value.

Furthermore, the examination bed control panel acquires the rotating speed of the driving motor through an electronic encoder.

Further, the examination table control board reads parameters of the driver through CANOPEN protocol, wherein the parameters comprise: rated voltage, output current.

Furthermore, the control panel of the examination bed interacts data with the workstation through a self-defined CAN bus protocol.

Has the advantages that: compared with the prior art, the invention has the following advantages:

the invention can obtain different equivalent weight values according to different body positions of a patient in the CT scanning process, and further adjust the ray dosage, so that the scanned image is clearer, and the ray received by the patient is smaller and more reasonable.

Drawings

Fig. 1 is a block diagram of an embodiment of a radiation dose control system in a CT system according to the present invention.

Detailed Description

The invention will be further described with reference to the accompanying drawings and specific embodiments. It is to be understood that the present invention may be embodied in various forms, and that there is no intention to limit the invention to the specific embodiments illustrated, but on the contrary, the intention is to cover some exemplary and non-limiting embodiments shown in the attached drawings and described below.

This embodiment provides an implementation manner of a method for controlling radiation dose in a CT system according to the present invention, where the CT system includes a table, a driver, and a driving motor, and the driving motor drives the table to move horizontally according to pulses output by the driver; the method comprises the following steps:

(1) constructing a relation between the equivalent weight of the examined person and the output current of the driver:

wherein, U represents the rated voltage of the driver, I represents the output current of the driver, R represents the driving radius of the driving motor, n represents the rotating speed of the motor, g represents the gravity acceleration, and mu represents the friction coefficient when the examination bed moves;

(2) in the checking process, when the checking bed moves at a constant speed, reading driver parameters including rated voltage and output current, and reading the rotating speed of a driving motor; then, according to the formula

Calculating the equivalent weight of the current examinee, and then adjusting the radiation dose according to the calculated weight m.

The specific method for adjusting the radiation dose according to the equivalent weight comprises the following steps: the larger the equivalent weight is, the longer the time for the same human body part to pass through the same position is, and at the moment, the dosage needs to be increased to ensure the accuracy of scanning data; conversely, a smaller equivalent weight indicates that the patient has less time to remain at this location throughout the scan, and less radiation can be used to penetrate the same tissue, thereby reducing the radiation dose and avoiding the patient being subjected to excessive radiation scanning. The specific dose is adjusted according to the specific scanning protocol used for scanning or according to the experience of the doctor.

In step (1), specifically, the formula

The derivation principle of (1) is as follows:

the formula I is as follows: P-FV, where P denotes the output power of the drive, F denotes the force applied to the couch by the drive motor, and V denotes the moving speed of the couch (i.e., the linear speed of the drive motor).

The formula II is as follows: t ═ FR, where T denotes the torque of the drive motor and R denotes the radius of action of the drive motor, since the table plate of the examination bed is moving horizontally, it is possible to obtain: f is mg μ, and μ is the friction coefficient of the table during movement.

The formula III is as follows: v ═ 2 pi Rn, where n denotes the drive motor speed.

The formula four is as follows: where U denotes the rated voltage and I denotes the output current.

The relation between the equivalent weight of the examinee and the output current of the driver can be obtained by the four formulas:

in step (2), specifically, after reading the driver parameters including the rated voltage, the output current, and the rotation speed of the driving motor, the U, I, n value is obtained, the radius of action R of the driving motor is related to the model of the driving motor, the circumferential ratio pi and the gravity acceleration g are constant and mu is the friction coefficient obtained by experiment in advance, so that, at this time, only U, I, n is substituted into the formula

The equivalent weight value can be calculated.

The invention also provides a control system of the ray dose in the CT system. Fig. 1 shows a schematic block diagram of an embodiment of a system for controlling radiation dose in a CT system according to the present invention. As shown in fig. 1, a radiation dose control system in a CT system includes: the device comprises an examination bed, an examination bed control board, a driver, a driving motor and a workstation; wherein the content of the first and second substances,

the examination bed control panel provides a user interaction window and generates a control signal of the driver according to the motion control parameters of the examination bed input by a user; reading the driver parameters and the rotating speed of the driving motor, calculating the weight of the checked person according to the read data and sending the weight to the workstation; the formula for calculating the equivalent weight of the examinee is as follows:

wherein, U represents the rated voltage of the driver, I represents the output current of the driver, R represents the driving radius of the driving motor, n represents the rotating speed of the motor, g represents the gravity acceleration, and mu represents the friction coefficient when the examination bed moves;

the driver generates a pulse waveform according to a control signal sent by the control panel of the examination bed, outputs the pulse waveform to the driving motor, and controls the driving motor to rotate so as to drive the examination bed to horizontally move;

the workstation receives the equivalent weight value of the examinee sent by the control panel of the examination bed, and adjusts the radiation dose in the scanning process according to the equivalent weight value.

Preferably, the examination bed control board acquires the rotating speed of the driving motor through an electronic encoder.

Preferably, the examination table control board reads parameters of the driver through CANOPEN protocol, and the parameters comprise: rated voltage, output current.

Preferably, the examination bed control board interacts data with the workstation through a custom CAN bus protocol.

It is to be understood that the features listed above for the different embodiments may be combined with each other to form further embodiments within the scope of the invention, where technically feasible. Furthermore, the particular examples and embodiments of the invention described are non-limiting, and various modifications may be made in the structure, steps, and sequence set forth above without departing from the scope of the invention.

The above-described embodiments, particularly any "preferred" embodiments, are possible examples of implementations, and are presented merely for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiments without departing substantially from the spirit and principles of the technology described herein, and such variations and modifications are to be considered within the scope of the invention.