scholarly journals Radio Frequency Coils for Hyperpolarized 13C Magnetic Resonance Experiments with a 3T MR Clinical Scanner: Experience from a Cardiovascular Lab

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 366
Author(s):  
Giulio Giovannetti ◽  
Alessandra Flori ◽  
Maria Filomena Santarelli ◽  
Vincenzo Positano ◽  
Nicola Martini ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Radio Frequency ◽  
Cardiac Metabolism ◽  
Estimation Methods ◽  
Field Pattern ◽  
Mouse Heart ◽  
Simulation Design ◽  
Hyperpolarized 13C ◽  
Coil Resistance

Hyperpolarized 13C magnetic resonance (MR) is a promising technique for the noninvasive assessment of the regional cardiac metabolism since it permits heart physiology studies in pig and mouse models. The main objective of the present study is to resume the work carried out at our electromagnetic laboratory in the field of radio frequency (RF) coil design, building, and testing. In this paper, first, we review the principles of RF coils, coil performance parameters, and estimation methods by using simulations, workbench, and MR imaging experiments. Then, we describe the simulation, design, and testing of different 13C coil configurations and acquisition settings for hyperpolarized studies on pig and mouse heart with a clinical 3T MRI scanner. The coil simulation is performed by developing a signal-to-noise ratio (SNR) model in terms of coil resistance, sample-induced resistance, and magnetic field pattern. Coil resistance was calculated from Ohm’s law and sample-induced resistances were estimated with a finite-difference time-domain (FDTD) algorithm. In contrast, the magnetic field per unit current was calculated by magnetostatic theory and a FDTD algorithm. The information could be of interest to graduate students and researchers working on the design and development of an MR coil to be used in 13C studies.

scholarly journals Wireless Power Transfer Using Harvested Radio Frequency Energy with Magnetic Resonance Coupling to Charge Mobile Device Batteries

2021 ◽  
Vol 11 (16) ◽  
pp. 7707
Author(s):  
Neetu Ramsaroop ◽  
Oludayo O. Olugbara
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Radio Frequency ◽  
Mobile Device ◽  
Receiver Coil ◽  
Wireless Power ◽  
Magnetic Resonance Coupling ◽  
Transmitter Coil ◽  
Resonance Coupling ◽  
Rf Energy

This research paper presents the design of a wireless power transfer (WPT) circuit integrated with magnetic resonance coupling (MRC) and harvested radio frequency (RF) energy to wirelessly charge the battery of a mobile device. A capacitor (100 µF, 16 V) in the RF energy harvesting circuit stored the converted power, and the accumulated voltage stored in the capacitor was 9.46 V. The foundation of the proposed WPT prototype circuit included two coils (28 AWG)—a transmitter coil, and a receiver coil. The transmitter coil was energized by the alternating current (AC), which produced a magnetic field, which in turn induced a current in the receiver coil. The harvested RF energy (9.46 V) was converted into AC, which energized the transmitter coil and generated a magnetic field. The electronics in the receiver coil then converted the AC into direct current (DC), which became usable power to charge the battery of a mobile device. The experimental setup based on mathematical modeling and simulation displayed successful charging capabilities of MRC, with the alternate power source being the harvested RF energy. Mathematical formulae were applied to calculate the amount of power generated from the prototype circuit. LTSpice simulation software was applied to demonstrate the behavior of the different components in the circuit layout for effective WPT transfer.

scholarly journals FREQUENCY NOISE INFLUENCE ON FUNCTIONING OF FREDKIN QUANTUM GATE

2010 ◽  
pp. 118-126
Author(s):  
Gennadiy P. Gorskyi ◽  
Vitaliy G. Deibuk
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Standard Deviation ◽  
Magnetic Resonance ◽  
Radio Frequency ◽  
Correct Answer ◽  
Quantum Gate ◽  
Frequency Noise ◽  
Fredkin Gate ◽  
Frequency Magnetic Field

The influence of detuning of radio frequency magnetic field (RFMF) on the functioning of nuclear magnetic resonance (NMR) quantum Fredkin gate is considered in this paper. It is shown that detuning of frequency decreases a probability of correct answer. If the spectral broadband of RFMF signal is increasing, then the main value of correct answer probability is decreasing too and standard deviation of this probability is increasing.

scholarly journals Homogenous nuclear magnetic resonance probe using the space harmonics suppression method

2020 ◽  
Vol 9 (1) ◽  
pp. 117-125
Author(s):  
Pauline de Pellegars ◽  
Liu Pan ◽  
Rahima Sidi-Boulenouar ◽  
Eric Nativel ◽  
Michel Zanca ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Radio Frequency ◽  
Signal To Noise ◽  
Space Harmonics ◽  
Saddle Coil ◽  
Radio Frequency Coils ◽  
Shs Method ◽  
Nuclear Magnetic

Abstract. Nuclear magnetic resonance imaging (MRI) has became an unavoidable medical tool in spite of its poor sensitivity. This fact motivates the efforts to enhance the nuclear magnetic resonance (NMR) probe performance. Thus, the nuclear spin excitation and detection, classically performed using radio-frequency coils, are required to be highly sensitive and homogeneous. The space harmonics suppression (SHS) method, already demonstrated to construct coil producing homogenous static magnetic field, is used in this work to design radio-frequency coils. The SHS method is used to determine the distribution of the electrical conductive wires which are organized in a saddle-coil-like configuration. The theoretical study of these SHS coils allows one to expect an enhancement of the signal-to-noise ratio with respect to saddle coil. Coils prototypes were constructed and tested to measure 1H NMR signal at a low magnetic field (8 mT) and perform MRI acquired at a high magnetic field (3 T). The signal-to-noise ratios of these SHS coils are compared to the one of saddle coil and birdcage (in the 3 T case) of the same size under the same pulse sequence conditions demonstrating the performance enhancement allowed by the SHS coils.

THE ELECTRON CYCLOTRON

1950 ◽  
Vol 28a (1) ◽  
pp. 73-91 ◽  
Author(s):  
P. A. Redhead ◽  
H. LeCaine ◽  
W. J. Henderson
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Radio Frequency ◽  
Constant Magnetic Field ◽  
Electron Cyclotron ◽  
Radio Frequency Field ◽  
Applied Frequency ◽  
Frequency Field

A magnetic resonance accelerator for electrons is described which was constructed on the principles suggested by Veksler. A constant magnetic field and applied frequency are employed, the frequency of the accelerating radio-frequency field being 2800 megacycles per second. Final energies of five million electron volts are obtained.

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