阅读说明：本技术 基于粒子加速器的核磁共振磁场测量方法及系统 (Nuclear magnetic resonance magnetic field measurement method and system based on particle accelerator ) 是由 袁双虎 李玮 方永祥 李莉 刘宁 吕慧颖 于金明 于 2020-05-12 设计创作，主要内容包括：本公开公开了基于粒子加速器的核磁共振磁场测量方法及系统,包括：利用粒子加速器,向核磁共振仪的待测量区域发射加速粒子；记录所述加速粒子在待测量区域内的运动轨迹及轨迹改变点；改变粒子加速器的发射角度,再次向核磁共振仪的待测量区域发射加速粒子；记录改变发射角度后,加速粒子在待测量区域内的运动轨迹及轨迹改变点；重复上一步设定次数；然后,对每个的运动轨迹,利用磁偏转法计算当前运动轨迹的磁场强度；对每个轨迹改变点,利用氢原子核自旋法计算当前轨迹改变点的磁场强度；基于所有运动轨迹的磁场强度和所有轨迹点的磁场强度,绘出磁场强度边界线,得到核磁共振仪的待测量区域的磁场强度。(The utility model discloses a nuclear magnetic resonance magnetic field measurement method and system based on a particle accelerator, which comprises the following steps: emitting accelerated particles to a region to be measured of a nuclear magnetic resonance instrument by using a particle accelerator; recording the motion track and the track change point of the accelerated particles in the area to be measured; changing the emission angle of the particle accelerator, and emitting accelerated particles to the region to be measured of the nuclear magnetic resonance instrument again; recording the motion track and the track change point of the accelerated particles in the area to be measured after the emission angle is changed; repeating the previous step for a set number of times; then, for each motion track, calculating the magnetic field intensity of the current motion track by using a magnetic deflection method; for each track change point, calculating the magnetic field intensity of the current track change point by using a hydrogen atomic nuclear spin method; and drawing a magnetic field intensity boundary line based on the magnetic field intensity of all the motion tracks and the magnetic field intensity of all the track points to obtain the magnetic field intensity of the region to be measured of the nuclear magnetic resonance instrument.)

1. The nuclear magnetic resonance magnetic field measurement method based on the particle accelerator is characterized by comprising the following steps:

emitting accelerated particles to a region to be measured of a nuclear magnetic resonance instrument by using a particle accelerator; recording the motion track and the track change point of the accelerated particles in the area to be measured;

changing the emission angle of the particle accelerator, and emitting accelerated particles to the region to be measured of the nuclear magnetic resonance instrument again; recording the motion track and the track change point of the accelerated particles in the area to be measured after the emission angle is changed;

repeating the previous step for a set number of times; then, for each motion track, calculating the magnetic field intensity of the current motion track by using a magnetic deflection method; for each track change point, calculating the magnetic field intensity of the current track change point by using a hydrogen atomic nuclear spin method;

and drawing a magnetic field intensity boundary line based on the magnetic field intensity of all the motion tracks and the magnetic field intensity of all the track points to obtain the magnetic field intensity of the region to be measured of the nuclear magnetic resonance instrument.

2. The method of claim 1, further comprising:

applying reverse magnetic field intensity to a region to be measured of the nuclear magnetic resonance apparatus;

emitting accelerated particles to a region to be measured of a nuclear magnetic resonance instrument by using a particle accelerator; recording the motion track of the accelerated particles in the region to be measured;

judging the sizes of the track deflection angle and a set threshold value, and returning to the step of utilizing the particle accelerator to emit accelerated particles to a region to be measured of the nuclear magnetic resonance spectrometer if the track deflection angle is larger than the set threshold value; if the track deflection angle is smaller than the set threshold value, correcting the size of the reverse magnetic field intensity, and returning to the region to be measured of the nuclear magnetic resonance apparatus to apply the reverse magnetic field intensity; if the track deflection angle is zero, the process is ended and the applied reverse magnetic field strength is output.

3. The method as claimed in claim 1, wherein for each motion trajectory, calculating the magnetic field strength of the current motion trajectory by using a magnetic deflection method; the method specifically comprises the following steps:

charged particles vertically enter a magnetic field, deflect due to Lorentz force and do uniform-speed circular motion;

according to the track, measuring the time t, the distance s and the circumferential radius r of uniform-speed circular motion, and calculating the corresponding magnetic field by combining the known nuclear-mass ratio q/m:

B＝ms/qrt。

4. the method as claimed in claim 1, wherein for each motion trajectory, calculating the magnetic field strength of the current motion trajectory by using a magnetic deflection method; the method specifically comprises the following steps:

taking the boundary point as a boundary, dividing the particle motion track into two arcs, respectively measuring the motion time, the corresponding central angle and the radius of the two arcs for a plurality of times, and obtaining a plurality of groups of magnetic field strengths corresponding to the two arcs according to a plurality of groups of data of the two arcs:

averaging the magnetic field strengths of the multiple groups:

to remove significant errors, if | B_i-B*|>λ, then, the measured B is indicated_iIf the error is too large, discarding the error, wherein lambda is a constant;

then, the rest data is subjected to averaging processing to obtain the magnetic field intensity corresponding to the two arcs, the two obtained magnetic field intensities can form a range, and the actual magnetic field intensity is within the range.

5. The method as claimed in claim 1, wherein for each trajectory change point, the magnetic field strength of the current trajectory change point is calculated by using a hydrogen nuclear spin method, specifically:

placing hydrogen nuclei at the current trajectory change point, and calculating the spin magnetic moment of the hydrogen nuclei:

μ＝epg/2M，

wherein e is the charge of the hydrogen nuclei, M is the mass of the hydrogen nuclei, and g is a constant determined by the nuclear structure;

p is the discrete value of the nuclear angular momentum;

wherein I is a spin quantum number, I ═ 0, 1/2, 1, 3/2, 2, 5/2, … …, n/2; n is a positive integer; and then the resonance condition can be obtained according to the interaction of the magnetic moment and the external magnetic field, and the magnetic field size of the corresponding point can be calculated.

6. The method as claimed in claim 1, wherein for each motion trajectory, calculating the magnetic field strength of the current motion trajectory by using a magnetic deflection method; for each track change point, calculating the magnetic field intensity of the current track change point by using a hydrogen atomic nuclear spin method; the method comprises the following specific steps:

the interaction of magnetic field B with magnetic moment can be:

E＝-μ×B＝-μ_ZB＝-γP_ZB＝-γmhB

wherein m is the number of quanta;

ΔE＝γhB

energy separation between adjacent energy levels;

the nuclear magnetic resonance instrument works to generate a radio frequency field, and the radio frequency field meets the resonance condition:

v＝γB/2π，

by measuring the resonance frequency v of the particles in the corresponding magnetic field_HFinding the corresponding magnetic field:

B＝v_H2π/γ。

7. the method as claimed in claim 1, wherein the magnetic field intensity measured by the magnetic deflection method and the hydrogen nuclear spin method is measured for a plurality of times, and the magnetic field intensity at any point is obtained by combining a planar rectangular coordinate system.

8. A nuclear magnetic resonance magnetic field measurement system based on a particle accelerator is characterized by comprising:

a transmit module configured to: emitting accelerated particles to a region to be measured of a nuclear magnetic resonance instrument by using a particle accelerator; recording the motion track and the track change point of the accelerated particles in the area to be measured;

an angle change module configured to: changing the emission angle of the particle accelerator, and emitting accelerated particles to the region to be measured of the nuclear magnetic resonance instrument again; recording the motion track and the track change point of the accelerated particles in the area to be measured after the emission angle is changed;

a magnetic field strength calculation module configured to: repeating the angle changing step for a set number of times; then, for each motion track, calculating the magnetic field intensity of the current motion track by using a magnetic deflection method; for each track change point, calculating the magnetic field intensity of the current track change point by using a hydrogen atomic nuclear spin method;

an output module configured to: and drawing a magnetic field intensity boundary line based on the magnetic field intensity of all the motion tracks and the magnetic field intensity of all the track points to obtain the magnetic field intensity of the region to be measured of the nuclear magnetic resonance instrument.

9. An electronic device comprising a memory and a processor and computer instructions stored on the memory and executable on the processor, the computer instructions when executed by the processor performing the method of any of claims 1-7.

10. A computer-readable storage medium storing computer instructions which, when executed by a processor, perform the method of any one of claims 1 to 7.

Technical Field

The disclosure relates to the technical field of medical equipment, in particular to a nuclear magnetic resonance magnetic field measurement method and system based on a particle accelerator.

Background

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

With the development of the times, the medical technology is also continuously improved in the face of the increasing number of tumor diseases. Through an electronic slip ring, a radiotherapy instrument and a nuclear magnetic resonance instrument are combined, and the obtained magnetic resonance accelerator can achieve the effect of positioning and radiotherapy. However, because the nmr is inside the electronic slip ring and works to generate a magnetic field, the hydrogen nuclei in the human body in the magnetic field are excited to cause the hydrogen nuclei to resonate and absorb energy, and the accelerated particles generated by the external particle accelerator are injected into the human body. In order to avoid the deflection of particles due to the Lorentz force generated by the particles passing through the magnetic field during the process of entering the human body, a magnetic field detection method is needed to accurately calibrate and detect the magnetic field in the nuclear magnetic resonance instrument.

The inventor finds that the traditional detection method is complex and can be completed only by assistance of other tools, and is obviously not suitable for a system in which a particle accelerator and a nuclear magnetic resonance spectrometer are combined.

Disclosure of Invention

In order to solve the deficiencies of the prior art, the present disclosure provides a nuclear magnetic resonance magnetic field measurement method and system based on a particle accelerator; the particle accelerator in the combined structure can be effectively utilized, and local materials can be obtained; and the boundary points are calculated by another method, so that the measurement of the measured magnetic field is more accurate and simpler.

In a first aspect, the present disclosure provides a particle accelerator-based nuclear magnetic resonance magnetic field measurement method;

the nuclear magnetic resonance magnetic field measurement method based on the particle accelerator comprises the following steps:

emitting accelerated particles to a region to be measured of a nuclear magnetic resonance instrument by using a particle accelerator; recording the motion track and the track change point of the accelerated particles in the area to be measured;

an angle changing step: changing the emission angle of the particle accelerator, and emitting accelerated particles to the region to be measured of the nuclear magnetic resonance instrument again; recording the motion track and the track change point of the accelerated particles in the area to be measured after the emission angle is changed;

repeating the angle changing step for a set number of times; then, for each motion track, calculating the magnetic field intensity of the current motion track by using a magnetic deflection method; for each track change point, calculating the magnetic field intensity of the current track change point by using a hydrogen atomic nuclear spin method;

and drawing a magnetic field intensity boundary line based on the magnetic field intensity of all the motion tracks and the magnetic field intensity of all the track points to obtain the magnetic field intensity of the region to be measured of the nuclear magnetic resonance instrument.

In a second aspect, the present disclosure provides a particle accelerator-based magnetic resonance magnetic field measurement system;

a nuclear magnetic resonance magnetic field measurement system based on a particle accelerator, comprising:

a transmit module configured to: emitting accelerated particles to a region to be measured of a nuclear magnetic resonance instrument by using a particle accelerator; recording the motion track and the track change point of the accelerated particles in the area to be measured;

an angle change module configured to: changing the emission angle of the particle accelerator, and emitting accelerated particles to the region to be measured of the nuclear magnetic resonance instrument again; recording the motion track and the track change point of the accelerated particles in the area to be measured after the emission angle is changed;

a magnetic field strength calculation module configured to: repeating the angle changing step for a set number of times; then, for each motion track, calculating the magnetic field intensity of the current motion track by using a magnetic deflection method; for each track change point, calculating the magnetic field intensity of the current track change point by using a hydrogen atomic nuclear spin method;

an output module configured to: and drawing a magnetic field intensity boundary line based on the magnetic field intensity of all the motion tracks and the magnetic field intensity of all the track points to obtain the magnetic field intensity of the region to be measured of the nuclear magnetic resonance instrument.

In a third aspect, the present disclosure also provides an electronic device comprising a memory and a processor, and computer instructions stored on the memory and executed on the processor, wherein when the computer instructions are executed by the processor, the method of the first aspect is performed.

In a fourth aspect, the present disclosure also provides a computer-readable storage medium for storing computer instructions which, when executed by a processor, perform the method of the first aspect.

Compared with the prior art, the beneficial effect of this disclosure is:

1. the magnetic field is measured in the particle accelerator of the combined particle accelerator and nuclear magnetic resonance spectrometer, and the particle accelerator is reasonably and effectively utilized, so that the measurement of the magnetic field is more accurate.

2. According to the method, the movement track and the track change point of the accelerated particles in the area to be measured are recorded, so that the recording and the measurement of the movement track of the particles are more accurate, the accuracy of magnetic field measurement is improved, and a reasonable coordinate system is combined, so that the accurate calibration of a magnetic field can be realized.

3. The method combines a magnetic deflection method and a hydrogen atomic nuclear spinning method, adopts different methods for different areas, and repeatedly measures the boundary area with changed magnetic field, so that the boundary track with changed magnetic field is clearer.

4. The hydrogen nuclear spin method adopted by the method accords with the positioning principle of nuclear magnetic resonance for medical tumor images, and can be mastered more quickly and operated and calculated more familiar to users.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not to limit the disclosure.

Fig. 1 is a flow chart of magnetic field measurement by magnetic deflection method according to a first embodiment of the present disclosure;

FIG. 2 is a flow chart of magnetic field measurement by hydrogen nuclear spin method according to a first embodiment of the disclosure;

FIG. 3 is a flowchart illustrating a process for processing the obtained data according to a first embodiment of the disclosure;

fig. 4 is an overall flowchart of the method according to the first embodiment of the disclosure.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

As described in the background, the existing magnetic field detection technology is complicated and requires other instruments to be connected, and it is obviously not suitable for the assembled device to be measured after being disassembled. In order to solve the problems, the disclosure provides a nuclear magnetic resonance magnetic field measurement and correction method and system based on a particle accelerator.