Finite size bi-planar gradient coil for MRI

Liu, Haiying

doi:10.1109/20.706838

Cited by 6 publications

(5 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The bi-planar coil is traditionally used for Magnetic Resonance Imaging (MRI) coil design, and details about the coil design can be found in references [19,21,35]. The bi-planar coil is also used for residual magnetic field compensation in a magnetic field shielding room, and details on how to design such a coil are demonstrated in references [22,24,26,36].…”

Section: Coil Designmentioning

confidence: 99%

“…It is difficult to miniaturize the typical three-axis coils, such as the Helmholtz coil. However, the bi-planar coil, which can produce three-dimensional magnetic fields with only two parallel planes of current confinement [19], gives us the opportunity to further miniaturize the devices. As we know, it is hard to fabricate a 3D Helmholtz coil in the micro-machined atomic magnetometer.…”

Section: Introductionmentioning

confidence: 99%

“…The bi-planar coil, which is typically used to produce stable magnetic fields or magnetic field gradients for field cancellation [9], has been widely used in Magnetic Resonance Imaging systems [19,21]. With the development of optically pumped magnetometers for MEG or MCG recording, the bi-planar coil was designed for field compensation in a magnetic field shield room [22,23].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

In Situ Study of the Magnetic Field Gradient Produced by a Miniature Bi-Planar Coil for Chip-Scale Atomic Devices

Chen,

Wang,

Zhang

et al. 2023

Micromachines

View full text Add to dashboard Cite

The miniaturization of quantum sensors is a popular trend for the development of quantum technology. One of the key components of these sensors is a coil which is used for spin modulation and manipulation. The bi-planar coils have the advantage of producing three-dimensional magnetic fields with only two planes of current confinement, whereas the traditional Helmholtz coils require three-dimensional current distribution. Thus, the bi-planar coils are compatible with the current micro-fabrication process and are quite suitable for the compact design of the chip-scale atomic devices that require stable or modulated magnetic fields. This paper presents a design of a miniature bi-planar coil. Both the magnetic fields produced by the coils and their inhomogeneities were designed theoretically. The magnetic field gradient is a crucial parameter for the coils, especially for generating magnetic fields in very small areas. We used a NMR (Nuclear Magnetic Resonance) method based on the relaxation of 131Xe nuclear spins to measure the magnetic field gradient in situ. This is the first time that the field inhomogeneities of the field of such small bi-planar coils have been measured. Our results indicate that the designed gradient caused error is 0.08 for the By and the Bx coils, and the measured gradient caused error using the nuclear spin relaxation method is 0.09±0.02, suggesting that our method is suitable for measuring gradients. Due to the poor sensitivity of our magnetometer under a large Bz bias field, we could not measure the Bz magnetic field gradient. Our method also helps to improve the gradients of the miniature bi-planar coil design, which is critical for chip-scale atomic devices.

show abstract

Section: Coil Designmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

In Situ Study of the Magnetic Field Gradient Produced by a Miniature Bi-Planar Coil for Chip-Scale Atomic Devices

Chen,

Wang,

Zhang

et al. 2023

Micromachines

View full text Add to dashboard Cite

show abstract

“…As a result, the inductance of the designed coil is always too large for practical applications. Following Turner's original approach, a number of modified methods were proposed by including the inductance of the coil in the objective function [2][3][4][5][6][7][8][9]. In these methods [2][3][4][5][6][7][8][9], the objective function is written with the gradient magnetic field and the stored magnetic energy (or the inductance), both of which are expressed by the surface current density.…”

Section: Introductionmentioning

confidence: 99%

“…Following Turner's original approach, a number of modified methods were proposed by including the inductance of the coil in the objective function [2][3][4][5][6][7][8][9]. In these methods [2][3][4][5][6][7][8][9], the objective function is written with the gradient magnetic field and the stored magnetic energy (or the inductance), both of which are expressed by the surface current density. Although these minimal-energy methods are theoretically feasible, they are sometimes difficult to implement into practical designs.…”

Section: Introductionmentioning

confidence: 99%

An optimized target-field method for MRI transverse biplanar gradient coil design

Zhang¹,

Xu²,

Fu³

et al. 2011

Meas. Sci. Technol.

View full text Add to dashboard Cite

Gradient coils are essential components of magnetic resonance imaging (MRI) systems. In this paper, we present an optimized target-field method for designing a transverse biplanar gradient coil with high linearity, low inductance and small resistance, which can well satisfy the requirements of permanent-magnet MRI systems. In this new method, the current density is expressed by trigonometric basis functions with unknown coefficients in polar coordinates. Following the standard procedures, we construct an objective function with respect to the total square errors of the magnetic field at all target-field points with the penalty items associated with the stored magnetic energy and the dissipated power. By adjusting the two penalty factors and minimizing the objective function, the appropriate coefficients of the current density are determined. Applying the stream function method to the current density, the specific winding patterns on the planes can be obtained. A novel biplanar gradient coil has been designed using this method to operate in a permanent-magnet MRI system. In order to verify the validity of the proposed approach, the gradient magnetic field generated by the resulted current density has been calculated via the Biot-Savart law. The results have demonstrated the effectiveness and advantage of this proposed method.

show abstract

A stream function method for gradient coil design

Lemdiasov¹,

Ludwig

2005

Concepts Magn. Reson.

128

131

View full text Add to dashboard Cite

ABSTRACT:A new design approach for the construction of gradient coils for magnetic resonance imaging is presented. The theoretical formulation involves a constraint cost function between the desired field in a particular region of interest in space and an almost arbitrarily defined surface that carries the current configuration based on Biot-Savart's integral equation. An appropriate weight function in conjunction with linear approximation functions permits the transformation of the problem formulation into a linear matrix equation whose solution yields discrete current elements in terms of magnitude and direction within a specified coil surface. Numerical predictions and comparisons with practical measurements for the G x , G y , G z gradient coils underscore the success of this approach in terms of achieving highly linear fields while maintaining low parasitic fields and low inductances.

show abstract

Finite size bi-planar gradient coil for MRI

Cited by 6 publications

References 1 publication

In Situ Study of the Magnetic Field Gradient Produced by a Miniature Bi-Planar Coil for Chip-Scale Atomic Devices

In Situ Study of the Magnetic Field Gradient Produced by a Miniature Bi-Planar Coil for Chip-Scale Atomic Devices

An optimized target-field method for MRI transverse biplanar gradient coil design

A stream function method for gradient coil design

Contact Info

Product

Resources

About