Chinese Journal of Magnetic Resonance >

2024 , Vol. 41 >Issue 2: 117 - 127

DOI: https://doi.org/10.11938/cjmr20233066

Articles

A Design of Active Shimming Power Supply for Magnetic Resonance Spectrometers

  • LIU Tingwei ,
  • PENG Bowen ,
  • XU Yajie ,
  • WANG Ya ,
  • WANG Feng ,
  • YU Peng ,
  • YANG Xiaodong
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  • 1. School of Electronic and Information Engineering, Changchun University of Science and Technology, Changchun 130022, China
    2. Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
    3. Jinan Guoke Medical Technology Development Co., Ltd., Jinan 250013, China
    4. University of Science and Technology of China, Hefei 230026, China
#Tel: 15250434900, E-mail: xuyj@sibet.ac.cn;

Received date: 2023-04-27

  Online published: 2023-05-30

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Abstract

Highly homogeneous magnetic fields in magnetic resonance spectrometers are an important guarantee for improving the quality of spectra for chemical structure analysis and kinetic information. The active shimming process using a shimming power supply to drive a shimming coil to produce a compensating electromagnetic field is an essential way to improve the homogeneity of the magnetic field. The high accuracy and stability of the shimming power supply’s output are crucial indicators for improving the active shimming capability and maintaining the shimming results. The paper develops a high-precision, high-stability, low-ripple active shimming power supply system for magnetic resonance spectrometers, and designs a shimming current driver (constant current source) with output state monitoring based on negative feedback control, coupled with an MCU control platform and host computer system to complete the closed-loop transmission of control commands and data between hardware and software, to achieve digital constant current output control. Under R=2.84 Ω, L=25.5 µH shimming coil load, the full-scale output response time is less than 18.9 µs, the output ripple peak-to-peak control is 30 mV, the positive and negative current output symmetry is good, and the maximum output deviation is 4.8‰ for long time operation. This power supply was used in a nuclear magnetic resonance spectrometer system using 0.5 T-Halbach configuration magnets, and the magnetic field homogeneity was optimised from 24.48 ppm (10-6) to 2.72 ppm by driving a first-order shimming coil. This work contributes to the integration of compact nuclear magnetic resonance spectrometer systems and the applications related to active shimming.

Key words： nuclear magnetic resonance; active shimming power supply; high precision; high stability; multi-channel

Cite this article

LIU Tingwei , PENG Bowen , XU Yajie , WANG Ya , WANG Feng , YU Peng , YANG Xiaodong . A Design of Active Shimming Power Supply for Magnetic Resonance Spectrometers[J]. Chinese Journal of Magnetic Resonance, 2024 , 41(2) : 117 -127 . DOI: 10.11938/cjmr20233066

References

[1] 毛希安. 现代核磁共振实用技术及应用[M]. 北京: 科学文献出版社, 2000.
[2] ERNST R R(毛希安译). 一维和二维核磁共振原理[M]. 北京: 科学出版社, 1997.
[3] 裘祖文, 裴奉奎. 核磁共振波谱[M]. 北京: 科学出版社, 1989.
[4] YU G J, LIU J, MAO S Z, et al. Exchange kinetics of surfactants TX-100 and CTAB investigated by 1H NMR spectroscopy[J]. Chinese J Magn Reson, 2016, 33(3): 422-431.
  俞刚金, 刘君, 毛诗珍, 等. TX-100和CTAB交换动力学的核磁共振研究[J]. 波谱学杂志, 2016, 33(3): 422-431.
[5] BECKER M, JOUDA M, KOLCHINSKAYA A, et al. Deep regression with ensembles enables fast, first-order shimming in low-field NMR[J]. J Magn Reson, 2022, 336: 107151.
[6] VAN GELDEREN P, DE ZWART J A, STAREWICZ P, et al. Real-time shimming to compensate for respiration-induced B0 fluctuations[J]. Magn Reson Med, 2007, 57(2): 362-368.
[7] 谈军. 核磁共振波谱仪匀场电源数据通信模块设计[D]. 厦门： 厦门大学, 2009.
[8] XU Y, YU P, JIA F, et al. A spherical harmonics decomposition method (SHDM) for irregular matrix coils design[J]. IEEE T Bio-Med Eng, 2021, 69(4): 1292-1301.
[9] TOPFER R, FOIAS A, STIKOV N, et al. Real-time correction of respiration-induced distortions in the human spinal cord using a 24-channel shim array[J]. Magn Reson Med, 2018, 80(3): 935-946.
[10] HUANG Q M, CHEN S S, ZHANG J Q, et al. Method of designing magnetic resonance active shimming coil based on target field point method and flow function[J]. Acta Phys Sin, 2019, 68(19): 198301.
  黄清明, 陈珊珊, 张建青, 等. 基于目标场点法和流函数的磁共振有源匀场线圈设计方法[J]. 物理学报, 2019, 68(19): 198301.
[11] TOPFER R, FOIAS A, STIKOV N, et al. Real-time correction of respiration-induced distortions in the human spinal cord using a 24-channel shim array[J]. Magn Reson Med, 2018, 80(3): 935-946.
[12] LI S, JIANG X. Digital controlled MOSFET gradient amplifier for magnetic resonance imaging[C]// Int Conf Electr Mach Syst. IEEE, 2011: 1-6.
[13] BLAMIRE A M, ROTHMAN D L, NIXON T. Dynamic shim updating: a new approach towards optimized whole brain shimming[J]. Magn Reson Med, 1996, 36(1): 159-165.
[14] KOCH K M, MCINTYRE S, NIXON T W, et al. Dynamic shim updating on the human brain[J]. J Magn Reson, 2006, 180(2): 286-296
[15] 宋侃. 高场核磁共振波谱仪匀场系统的研究[D]. 北京： 中国科学院研究生院(武汉物理与数学研究所), 2016.
[16] STOCKMANN J P, WITZEL T, KEIL B, et al. A 32-channel combined RF and B0 shim array for 3 T brain imaging[J]. Magn Reson Med, 2016, 75(1): 441-451.
[17] ZHOU Z C, SUN Z H. Design of dynamic shim amplifier based on DSP[J]. Autom Instrum, 2011, 26(2): 45-49.
  周泽畅, 孙宗海. 基于DSP的动态匀场放大器设计[J]. 自动化与仪表, 2011, 26(2): 45-49.
[18] 刘畅. 磁共振成像系统匀场电源优化设计[D]. 成都： 西南交通大学, 2018.
[19] CHEN S S, XIA T, BI X, et al. Design and implementation of an active shimming system for low field NMR analyzers[J]. Chinese J Magn Reson, 2017, 34(1): 87-99.
  陈珊珊, 夏天, 毕昕, 等. 高性能核磁共振弛豫分析仪匀场系统的设计与实现[J]. 波谱学杂志, 2017, 34(1): 87-99.
[20] 王玉. 核磁共振室温匀场电源与场频联锁系统一体化——核心板高速电路设计[D]. 厦门: 厦门大学, 2012.
[21] XU Y J, CHEN Q Y, ZHANG G C, et al. Shim coils design for Halbach magnet based on target field method[J]. Appl Magn Reson, 2015, 46(7): 823-836.
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