Method for designing elliptic cylindrical surface transverse gradient coil based on spatial alternation

Abstract

The invention discloses a method for designing an elliptic cylindrical surface transverse gradient coil based on spatial alternation. The method is characterized by comprising the steps that firstly, two shafts of the elliptic cylindrical surface where the gradient coil is located are defined to be in the direction x and the direction y, the shaft length of the elliptic cylindrical surface where the gradient coil is located in the direction x is 2a, the shaft length in the direction y is 2b, the wiring length in the axial direction is 2L, the strength of the gradient field is G, and the linearity is E; secondly, spatial alternation is utilized for converting the elliptic cylindrical surface into a cylindrical face, and the current density basis function and the expression are constructed under the cylindrical face; thirdly, a functional construction related to the current density is built, and the coefficient of the current density expression is obtained by solving the functional extreme value; fourthly, the solved coefficient of the current density expression is utilized for solving distribution of current density in the space, and the wiring shape of the gradient coil is obtained. The complex calculation of gradient coil designed through the network discrete method is avoided, and the high efficiency and precision are obtained.

Description

technical field [0001] The invention relates to a design method of a transverse gradient coil, in particular to a design method of an elliptical cylinder transverse gradient coil based on space transformation in a nuclear magnetic resonance imaging system. The invention belongs to the field of nuclear magnetic resonance imaging system component design. Background technique [0002] The gradient coil is one of the key components of the MRI system, and its main function is to provide the MRI system with alternating gradient magnetic fields in three orthogonal directions, so as to realize the spatial positioning of the imaged object. The structure of the gradient coil mainly includes two types: closed type and open type. [0003] The shape of the open gradient coil is a planar structure. Over the past few decades, permanent magnet-based NMR systems have dominated the market. The permanent magnet NMR system is generally an open system. Therefore, the research on the design a...

AI Technical Summary

Problems solved by technology

At present, there are few studies on the design theory of elliptical cylindrical gradient coils, and the lack of accurate, fast and efficient design schemes for elliptical cylindrical gradient coils has brought certain difficulties to the design and application of elliptical cylindrical gradient coils.

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