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Latypova AA, Yaremenko AV, Pechnikova NA, Minin AS, Zubarev IV. Magnetogenetics as a promising tool for controlling cellular signaling pathways. J Nanobiotechnology 2024; 22:327. [PMID: 38858689 PMCID: PMC11163773 DOI: 10.1186/s12951-024-02616-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 06/04/2024] [Indexed: 06/12/2024] Open
Abstract
Magnetogenetics emerges as a transformative approach for modulating cellular signaling pathways through the strategic application of magnetic fields and nanoparticles. This technique leverages the unique properties of magnetic nanoparticles (MNPs) to induce mechanical or thermal stimuli within cells, facilitating the activation of mechano- and thermosensitive proteins without the need for traditional ligand-receptor interactions. Unlike traditional modalities that often require invasive interventions and lack precision in targeting specific cellular functions, magnetogenetics offers a non-invasive alternative with the capacity for deep tissue penetration and the potential for targeting a broad spectrum of cellular processes. This review underscores magnetogenetics' broad applicability, from steering stem cell differentiation to manipulating neuronal activity and immune responses, highlighting its potential in regenerative medicine, neuroscience, and cancer therapy. Furthermore, the review explores the challenges and future directions of magnetogenetics, including the development of genetically programmed magnetic nanoparticles and the integration of magnetic field-sensitive cells for in vivo applications. Magnetogenetics stands at the forefront of cellular manipulation technologies, offering novel insights into cellular signaling and opening new avenues for therapeutic interventions.
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Affiliation(s)
- Anastasiia A Latypova
- Institute of Future Biophysics, Dolgoprudny, 141701, Russia
- Moscow Center for Advanced Studies, Moscow, 123592, Russia
| | - Alexey V Yaremenko
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
- Aristotle University of Thessaloniki, Thessaloniki, 54124, Greece.
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997, Russia.
| | - Nadezhda A Pechnikova
- Aristotle University of Thessaloniki, Thessaloniki, 54124, Greece
- Saint Petersburg Pasteur Institute, Saint Petersburg, 197101, Russia
| | - Artem S Minin
- M.N. Mikheev Institute of Metal Physics of the Ural Branch of the Russian Academy of Sciences, Yekaterinburg, 620108, Russia
| | - Ilya V Zubarev
- Institute of Future Biophysics, Dolgoprudny, 141701, Russia.
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2
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Yu P, Wang Y, Xu Y, Wu Z, Zhao Y, Peng B, Wang F, Tang Y, Yang X. Theoretical foundation for designing multilayer Halbach array magnets for benchtop NMR and MRI. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 344:107322. [PMID: 36332512 DOI: 10.1016/j.jmr.2022.107322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 10/21/2022] [Accepted: 10/23/2022] [Indexed: 06/16/2023]
Abstract
Multilayer Halbach array magnets support portable NMR and MRI, but optimizing their design to maximize performance and minimize the use of expensive magnet materials is challenging. This is partly because our theoretical understanding of such arrays is incomplete and computationally intensive. Here we provide a theoretical description of the magnetic field distribution and we demonstrate that inhomogeneity is greatest along the z axis in multilayer Halbach array magnets. This allows the configuration of the multilayer Halbach array magnets to be optimized in a way that takes into account homogeneity, magnet volume, and magnetic flux density. At the same time, our description simplifies the design of multilayer array magnets, while accommodating the possibility of different outer radii, lengths for each layer array, or the presence of separation between the rings. We validated the theoretical description in simulations of a three-layer Halbach array magnet, then with a prototype three-layer 1-T Halbach array magnet. After adjusting the position of magnet blocks in the neighboring rings, we achieved homogeneity of 220 ppm for a standard 5 mm NMR tube while the inner diameter of the magnet is 20 mm. Our work provides a theoretical foundation for designing multilayer Halbach array magnets to maximize homogeneity and minimize the use of magnet materials.
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Affiliation(s)
- Peng Yu
- School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China; Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China; Jinan Guoke Medical Technology Development Co., Ltd., Jinan 250101, China
| | - Ya Wang
- School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China; Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Yajie Xu
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Zhongyi Wu
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Ying Zhao
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Bowen Peng
- School of Biomedical Engineering (Suzhou), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China; Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China
| | - Feng Wang
- School of Electronic and Information Engineering, Changchun University of Science and Technology, 130022 Changchun, China
| | - Yuguo Tang
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China.
| | - Xiaodong Yang
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China.
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3
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Compact brain MRI. Nat Biomed Eng 2021; 5:201-202. [PMID: 33727710 DOI: 10.1038/s41551-021-00702-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
Nuclear magnetic resonance at low field strength is an insensitive spectroscopic technique, precluding portable applications with small sample volumes, such as needed for biomarker detection in body fluids. Here we report a compact double resonant chip stack system that implements in situ dynamic nuclear polarisation of a 130 nL sample volume, achieving signal enhancements of up to - 60 w.r.t. the thermal equilibrium level at a microwave power level of 0.5 W. This work overcomes instrumental barriers to the use of NMR detection for point-of-care applications.
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Bogaychuk A, Kuzmin V. Accounting for material imperfections in the design and optimization of low cost Halbach magnets. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:103904. [PMID: 33138559 DOI: 10.1063/5.0013274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 10/06/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate an experimental method for the improvement of the magnetic field homogeneity in Halbach magnets by taking magnet material imperfection into account. This method relies on the determination of the magnetization magnitude only for individual magnet blocks based on nuclear magnetic resonance field measurements in a simplified system, which, in our case, consists of four blocks. Then, a set of configurations with highest homogeneities can be found from simplified field map simulations of all possible configurations or by applying sophisticated optimum search algorithms if the number of blocks is large. Finally, the residual effect of angular magnetization deviations can be reduced by the experimental selection of the best configuration from the set found on the simulation step. This selection strategy is based on the conclusions made from statistical analysis of simulated field maps. By applying the described method to our eight-element magnet, we experimentally achieved tenfold field homogeneity improvement. Thus, in the best configuration, we obtained an average value of the magnetic field of 598.0 mT and a half-width of 226.9 ppm for a sample with a diameter of 4 mm and a height of 10 mm. These parameters along with the compact magnet size (40 × 40 × 102 mm3) and weight (0.6 kg) provide reasonable magnet quality compared with analogous systems having more complex magnet arrangements and significantly higher costs.
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Affiliation(s)
- A Bogaychuk
- Institute of Physics, Kazan Federal University, Kremlyovskaya Str. 18, Kazan 420008, Russia
| | - V Kuzmin
- Institute of Physics, Kazan Federal University, Kremlyovskaya Str. 18, Kazan 420008, Russia
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6
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Huber C, Goertler M, Abert C, Bruckner F, Groenefeld M, Teliban I, Suess D. Additive Manufactured and Topology Optimized Passive Shimming Elements for Permanent Magnetic Systems. Sci Rep 2018; 8:14651. [PMID: 30279477 PMCID: PMC6168460 DOI: 10.1038/s41598-018-33059-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/20/2018] [Indexed: 11/30/2022] Open
Abstract
A method to create a highly homogeneous magnetic field by applying topology optimized, additively manufactured passive shimming elements is investigated. The topology optimization algorithm can calculate a suitable permanent and nonlinear soft magnetic design that fulfills the desired field properties. The permanent magnetic particles are bonded in a polyamide matrix and they are manufactured with a low-cost, end-user 3D printer. Stray field measurements and an inverse stray field simulation framework can determine printing and magnetization errors. The customized shimming elements are manufactured by a selective melting process which produces completely dense soft magnetic metal parts. The methodology is demonstrated on a simple example of two axial symmetric cylindrical magnets, which generates a high inhomogeneous magnetic field. In this case, the maximum magnetic field density is 25 mT and the the homogeneity can be increased by a factor of 35 or down to 6‰. Simulation and measurement results point out a good conformity. Additional topology optimizations of more than one shimming element layer show the opportunity to make the manufactured magnetic system even more homogeneous.
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Affiliation(s)
- Christian Huber
- Physics of Functional Materials, University of Vienna, 1090, Vienna, Austria. .,Christian Doppler Laboratory for Advanced Magnetic Sensing and Materials, 1090, Vienna, Austria.
| | - Michael Goertler
- Institute for Surface Technologies and Photonics, Joanneum Research Forschungsgesellschaft GmbH, 8712, Niklasdorf, Austria
| | - Claas Abert
- Physics of Functional Materials, University of Vienna, 1090, Vienna, Austria.,Christian Doppler Laboratory for Advanced Magnetic Sensing and Materials, 1090, Vienna, Austria
| | - Florian Bruckner
- Physics of Functional Materials, University of Vienna, 1090, Vienna, Austria.,Christian Doppler Laboratory for Advanced Magnetic Sensing and Materials, 1090, Vienna, Austria
| | | | | | - Dieter Suess
- Physics of Functional Materials, University of Vienna, 1090, Vienna, Austria.,Christian Doppler Laboratory for Advanced Magnetic Sensing and Materials, 1090, Vienna, Austria
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Yu P, Xu Y, Wu Z, Chang Y, Chen Q, Yang X. A low-cost home-built NMR using Halbach magnet. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 294:162-168. [PMID: 30055440 DOI: 10.1016/j.jmr.2018.07.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 07/20/2018] [Accepted: 07/20/2018] [Indexed: 05/03/2023]
Abstract
The objective of this work is to develop a low-cost compact desktop NMR system based on Halbach magnets with the advantages of small size and ability to generate relatively high field strength. Considering the cost of manufacturing and assembling the magnetic blocks, the system utilized a 3-layer Halbach magnet and a wedge-shaped mechanical structure, which was designed for magnet rapid assembling. The comparison between simulation and calculation results of the initial magnetic field strength distribution showed that design theory and practice were in accordance. The initial homogeneity was 576 ppm in a square with a length of 5 mm. After passive shimming with two magnetic blocks and steel pieces, the uniformity reached 120 ppm in the same area. We developed and tested a compact single board spectrometer with digital modulation and demodulation in order to enhance the system mobility and improve the SNR. A self-made probe was used to carry out experiments with the spectrometer, and the spectral width at half-height reached 20 ppm in a cylinder with a diameter of 1.5 mm and a length of 1 mm. Compact structure and low cost of the system will facilitate and extend the application of desktop NMR system.
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Affiliation(s)
- Peng Yu
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, Jiangsu, China
| | - Yajie Xu
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, Jiangsu, China
| | - Zhongyi Wu
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, Jiangsu, China
| | - Yan Chang
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, Jiangsu, China
| | - Qiaoyan Chen
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, Jiangsu, China
| | - Xiaodong Yang
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, Jiangsu, China.
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8
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Hibino Y, Sugahara K, Muro Y, Tanaka H, Sato T, Kondo Y. Simple and low-cost tabletop NMR system for chemical-shift-resolution spectra measurements. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 294:128-132. [PMID: 30036813 DOI: 10.1016/j.jmr.2018.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/08/2018] [Accepted: 07/06/2018] [Indexed: 05/03/2023]
Abstract
We have been working on developing a low-cost tabletop NMR system. We reported that a field homogeneity as high as 50 ppm was achieved with a simple NMR magnet by employing two facing ferrite magnets with iron disks in between (Chonlathep et al., 2017). In this paper, we report two improvements added to our previous system: (1) an FPGA based signal processing unit to improve the S/N ratio and (2) a simple shimming mechanism to improve the field homogeneity. We obtained as high as 1 ppm field homogeneity in the best case. The signals from hydrogen nuclear spins in a methyl and carboxy group in acetic acid were resolved in NMR spectra.
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Affiliation(s)
- Y Hibino
- Graduate School of Science and Engineering Research, Kindai University, 577-8502 Higashi-Osaka, Japan.
| | - K Sugahara
- Graduate School of Science and Engineering Research, Kindai University, 577-8502 Higashi-Osaka, Japan; Department of Electronics and Engineering, Kindai University, 577-8502 Higashi-Osaka, Japan.
| | - Y Muro
- THAMWAY Co., Ltd, 417-0001 Fuji, Japan
| | - H Tanaka
- THAMWAY Co., Ltd, 417-0001 Fuji, Japan
| | - T Sato
- THAMWAY Co., Ltd, 417-0001 Fuji, Japan
| | - Y Kondo
- Graduate School of Science and Engineering Research, Kindai University, 577-8502 Higashi-Osaka, Japan; Department of Physics, Kindai University, 577-8502 Higashi-Osaka, Japan.
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9
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Blümich B, Rehorn C, Zia W. Magnets for Small-Scale and Portable NMR. MICRO AND NANO SCALE NMR 2018. [DOI: 10.1002/9783527697281.ch1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Bernhard Blümich
- RWTH Aachen University, Institut für Technische und Makromolekulare Chemie; Worringerweg 2 52074 Aachen Germany
| | - Christian Rehorn
- RWTH Aachen University, Institut für Technische und Makromolekulare Chemie; Worringerweg 2 52074 Aachen Germany
| | - Wasif Zia
- Sir Peter Mansfield Imaging Center, University of Nottingham; United Kingdom
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10
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Wang Q, Gao R, Liu S. Topology optimization based design of unilateral NMR for generating a remote homogeneous field. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 279:51-59. [PMID: 28463746 DOI: 10.1016/j.jmr.2017.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 04/07/2017] [Accepted: 04/07/2017] [Indexed: 06/07/2023]
Abstract
This paper presents a topology optimization based design method for the design of unilateral nuclear magnetic resonance (NMR), with which a remote homogeneous field can be obtained. The topology optimization is actualized by seeking out the optimal layout of ferromagnetic materials within a given design domain. The design objective is defined as generating a sensitive magnetic field with optimal homogeneity and maximal field strength within a required region of interest (ROI). The sensitivity of the objective function with respect to the design variables is derived and the method for solving the optimization problem is presented. A design example is provided to illustrate the utility of the design method, specifically the ability to improve the quality of the magnetic field over the required ROI by determining the optimal structural topology for the ferromagnetic poles. Both in simulations and experiments, the sensitive region of the magnetic field achieves about 2 times larger than that of the reference design, validating validates the feasibility of the design method.
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Affiliation(s)
- Qi Wang
- State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024, China
| | - Renjing Gao
- State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024, China
| | - Shutian Liu
- State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024, China.
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11
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Tayler MCD, Sakellariou D. Low-cost, pseudo-Halbach dipole magnets for NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 277:143-148. [PMID: 28285144 DOI: 10.1016/j.jmr.2017.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/01/2017] [Accepted: 03/02/2017] [Indexed: 05/27/2023]
Abstract
We present designs for compact, inexpensive and strong dipole permanent magnets aimed primarily at magnetic resonance applications where prepolarization and detection occur at different locations. Low-homogeneity magnets with a 7.5mm bore size and field up to nearly 2T are constructed using low-cost starting materials, standard workshop tools and only few hours of labor - an achievable project for a student or postdoc with spare time. As an application example we show how our magnet was used to polarize the nuclear spins in approximately 1mL of pure [13C]-methanol prior to detection of its high-resolution NMR spectrum at zero field (measurement field below 10-10T), where signals appear at multiples of the carbon-hydrogen spin-spin coupling frequency 1JCH=140.7(1)Hz.
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Affiliation(s)
- Michael C D Tayler
- Magnetic Resonance Research Center, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK; Department of Physics, University of California, Berkeley, CA 94720, USA.
| | - Dimitrios Sakellariou
- NIMBE, CEA-CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
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12
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Chonlathep K, Sakamoto T, Sugahara K, Kondo Y. A simple and low-cost permanent magnet system for NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 275:114-119. [PMID: 28043004 DOI: 10.1016/j.jmr.2016.12.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 12/13/2016] [Accepted: 12/19/2016] [Indexed: 06/06/2023]
Abstract
We have developed a simple, easy to build, and low-cost magnet system for NMR, of which homogeneity is about 4×10-4 at 57mT, with a pair of two commercially available ferrite magnets. This homogeneity corresponds to about 90Hz spectral resolution at 2.45MHz of the hydrogen Larmor frequency. The material cost of this NMR magnet system is little more than $100. The components can be printed by a 3D printer.
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Affiliation(s)
- K Chonlathep
- Grad. Sch. of Sci. and Eng., Kindai Univ., 577-8502 Higashi Osaka, Japan.
| | - T Sakamoto
- Dept. of Ele. and Eng., Kindai Univ., 577-8502 Higashi Osaka, Japan.
| | - K Sugahara
- Grad. Sch. of Sci. and Eng., Kindai Univ., 577-8502 Higashi Osaka, Japan; Dept. of Ele. and Eng., Kindai Univ., 577-8502 Higashi Osaka, Japan.
| | - Y Kondo
- Grad. Sch. of Sci. and Eng., Kindai Univ., 577-8502 Higashi Osaka, Japan; Dept. of Phys., Kindai Univ., 577-8502 Higashi Osaka, Japan.
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13
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Öztürk Y, Aktaş B. Note: 3D printed spheroid for uniform magnetic field generation. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:106103. [PMID: 27802690 DOI: 10.1063/1.4965035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This article is focused on a novel and practical production method for a uniform magnetic field generator. The method involves building of a surface coil template using a desktop 3D printer and winding of a conducting wire onto the structure using surface grooves as a guide. Groove pattern was based on the parametric spheroidal helical coil formula. The coil was driven by a current source and the magnetic field inside was measured using a Hall probe placed into the holes on the printed structure. The measurements are found to be in good agreement with our finite element analysis results and indicate a fairly uniform field inside.
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Affiliation(s)
- Y Öztürk
- TÜBITAK BILGEM, Gebze Yerleşkesi, 41470 Kocaeli, Turkey
| | - B Aktaş
- Physics Department, Gebze Technical University (GTU), 41400 Kocaeli, Turkey
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14
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Parker AJ, Zia W, Rehorn CWG, Blümich B. Shimming Halbach magnets utilizing genetic algorithms to profit from material imperfections. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 265:83-89. [PMID: 26874333 DOI: 10.1016/j.jmr.2016.01.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 01/14/2016] [Accepted: 01/19/2016] [Indexed: 06/05/2023]
Abstract
In recent years, permanent magnet-based NMR spectrometers have resurfaced as low-cost portable alternatives to superconducting instruments. While the development of these devices as well as clever shimming methods have yielded impressive advancements, scaling the size of these magnets to miniature lengths remains a problem to be addressed. Here we present the results of a study of a discrete shimming scheme for NMR Mandhalas constructed from a set of individual magnet blocks. While our calculations predict a modest reduction in field deviation by a factor of 9.3 in the case of the shimmed ideal Mandhala, a factor of 28 is obtained in the case of the shimmed imperfect Mandhala. This indicates that imperfections of magnet blocks can lead to improved field homogeneity. We also present a new algorithm to improve the homogeneity of a permanent magnet assembly. Strategies for future magnet construction can improve the agreement between simulation and practical implementation by using data from real magnets in these assemblies as the input to such an algorithm to optimize the homogeneity of a given design.
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Affiliation(s)
- Anna J Parker
- Institut für Technische und Makromolekulare Chemie, RWTH-Aachen University, Worringerweg 2, 52074 Aachen, Germany.
| | - Wasif Zia
- Institut für Technische und Makromolekulare Chemie, RWTH-Aachen University, Worringerweg 2, 52074 Aachen, Germany
| | - Christian W G Rehorn
- Institut für Technische und Makromolekulare Chemie, RWTH-Aachen University, Worringerweg 2, 52074 Aachen, Germany
| | - Bernhard Blümich
- Institut für Technische und Makromolekulare Chemie, RWTH-Aachen University, Worringerweg 2, 52074 Aachen, Germany
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15
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Dabaghyan M, Muradyan I, Hrovat A, Butler J, Frederick E, Zhou F, Kyriazis A, Hardin C, Patz S, Hrovat M. A portable single-sided magnet system for remote NMR measurements of pulmonary function. NMR IN BIOMEDICINE 2014; 27:1479-89. [PMID: 24953556 PMCID: PMC4232986 DOI: 10.1002/nbm.3149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 04/26/2014] [Accepted: 04/30/2014] [Indexed: 06/03/2023]
Abstract
In this work, we report initial results from a light-weight, low field magnetic resonance device designed to make relative pulmonary density measurements at the bedside. The development of this device necessarily involves special considerations for the magnet, RF and data acquisition schemes as well as a careful analysis of what is needed to provide useful information in the ICU. A homogeneous field region is created remotely from the surface of the magnet such that when the magnet is placed against the chest, an NMR signal is measured from a small volume in the lung. In order to achieve portability, one must trade off field strength and therefore spatial resolution. We report initial measurements from a ping-pong ball size region in the lung as a function of lung volume. As expected, we measured decreased signal at larger lung volumes since lung density decreases with increasing lung volume. Using a CPMG sequence with ΔTE=3.5 ms and a 20 echo train, a signal to noise ratio ~1100 was obtained from an 8.8mT planar magnet after signal averaging for 43 s. This is the first demonstration of NMR measurements made on a human lung with a light-weight planar NMR device. We argue that very low spatial resolution measurements of different lobar lung regions will provide useful diagnostic information for clinicians treating Acute Respiratory Distress Syndrome as clinicians want to avoid ventilator pressures that cause either lung over distension (too much pressure) or lung collapse (too little pressure).
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16
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Zalesskiy SS, Danieli E, Blümich B, Ananikov VP. Miniaturization of NMR systems: desktop spectrometers, microcoil spectroscopy, and "NMR on a chip" for chemistry, biochemistry, and industry. Chem Rev 2014; 114:5641-94. [PMID: 24779750 DOI: 10.1021/cr400063g] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Sergey S Zalesskiy
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences , Moscow, 119991, Russia
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Horch C, Schlayer S, Stallmach F. High-pressure low-field 1H NMR relaxometry in nanoporous materials. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 240:24-33. [PMID: 24508760 DOI: 10.1016/j.jmr.2014.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 12/10/2013] [Accepted: 01/08/2014] [Indexed: 06/03/2023]
Abstract
A low-field NMR sensor with NdFeB permanent magnets (B0=118 mT) and a pressure cell made of PEEK (4 cm outer diameter) were designed for (1)H relaxation time studies of adsorbed molecules at pressures of up to 300 bar. The system was used to investigate methane uptake of microporous metal-organic frameworks and nanoporous activated carbon. T2 relaxation time distribution of pure methane and of methane under co-adsorption of carbon dioxide show that the host-guest interaction lead to a relaxation time contrasts, which may be used to distinguish between the gas phase and the different adsorbed phases of methane. Adsorption isotherms, exchange of methane between adsorbent particles and the surrounding gas phase, successive displacement of methane from adsorption sites by co-adsorption of carbon dioxide and CO2/CH4 adsorption separation factors were determined from the observed NMR relaxation time distributions.
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Affiliation(s)
- Carsten Horch
- University of Leipzig, Faculty for Physics and Earth Sciences, Linnstrae 5, 04103 Leipzig, Germany
| | - Stefan Schlayer
- University of Leipzig, Faculty for Physics and Earth Sciences, Linnstrae 5, 04103 Leipzig, Germany
| | - Frank Stallmach
- University of Leipzig, Faculty for Physics and Earth Sciences, Linnstrae 5, 04103 Leipzig, Germany.
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Li X, Xia L, Chen W, Liu F, Crozier S, Xie D. Finite element analysis of gradient z-coil induced eddy currents in a permanent MRI magnet. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 208:148-155. [PMID: 21106418 DOI: 10.1016/j.jmr.2010.10.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 10/28/2010] [Accepted: 10/28/2010] [Indexed: 05/30/2023]
Abstract
In permanent magnetic resonance imaging (MRI) systems, pulsed gradient fields induce strong eddy currents in the conducting structures of the magnet body. The gradient field for image encoding is perturbed by these eddy currents leading to MR image distortions. This paper presents a comprehensive finite element (FE) analysis of the eddy current generation in the magnet conductors. In the proposed FE model, the hysteretic characteristics of ferromagnetic materials are considered and a scalar Preisach hysteresis model is employed. The developed FE model was applied to study gradient z-coil induced eddy currents in a 0.5 T permanent MRI device. The simulation results demonstrate that the approach could be effectively used to investigate eddy current problems involving ferromagnetic materials. With the knowledge gained from this eddy current model, our next step is to design a passive magnet structure and active gradient coils to reduce the eddy current effects.
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Affiliation(s)
- Xia Li
- Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, China.
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Robotic magnetic steering and locomotion of capsule endoscope for diagnostic and surgical endoluminal procedures. ROBOTICA 2009. [DOI: 10.1017/s0263574709990361] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
SUMMARYThis paper describes a novel approach to capsular endoscopy that takes advantage of active magnetic locomotion in the gastrointestinal tract guided by an anthropomorphic robotic arm. Simulations were performed to select the design parameters allowing an effective and reliable magnetic link between the robot end-effector (endowed with a permanent magnet) and the capsular device (endowed with small permanent magnets). In order to actively monitor the robotic endoluminal system and to efficiently perform diagnostic and surgical medical procedures, a feedback control based on inertial sensing was also implemented. The proposed platform demonstrated to be a reliable solution to move and steer a capsular device in a slightly insufflated gastrointestinal lumen.
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