High-voltage high-current small-ripple-wave gradient amplifier

Abstract

The invention relates to a high-voltage high-current small-ripple-wave gradient amplifier which is used for driving a gradient coil and further generating a gradient field needed by imaging of a magnetic resonance system. The high-voltage high-current small-ripple-wave gradient amplifier is composed of a signal processing and controlling part, a high-voltage power conversion part, a low-voltage power conversion part and a low-pass filtering part. The high-voltage high-current small-ripple-wave gradient amplifier can use different power conversion parts according to different characteristics of input and output signals, the needed target gradient field is generated rapidly and accurately by outputting filtering waves, and output ripple-wave current is reduced as mush as possible. The gradient amplifier can simplify the design of a high-voltage high-current amplifier, reduce hardware cost, improve system efficiency and optimize the performance of a gradient system to the maximum extent.

Description

technical field [0001] The invention relates to a gradient amplifier for generating and controlling pulse currents in gradient coils in a magnetic resonance imaging system. Background technique [0002] The gradient system refers to all circuit units related to the gradient magnetic field. Its function is to provide the system with a rapidly switchable gradient field with linearity and precision that meets the requirements, so as to dynamically modify the main magnetic field and realize the spatial positioning of imaging voxels. In the gradient system, the control signal generated by the gradient waveform generator is used as the input of the gradient amplifier, and the current output of the gradient amplifier drives three sets of gradient coils to generate a gradient field in the imaging space, giving the spatial coordinates of the imaging site, so that each pixel in the image is consistent with the human body. One-to-one correspondence of imaging parts. [0003] The grad...

AI Technical Summary

Problems solved by technology

The gradient amplifiers commonly used at this stage all adopt a single high-voltage power conversion structure

In the current period or even for a period of time, high-voltage power devices cannot achieve high-frequency switching. With the continuous increase in high-voltage voltage requirements, a single high-voltage power conversion structure cannot achieve both short settling time and low ripple current.

At the same time, the implementation of this single high-voltage power conversion topology, as the high-voltage voltage increases, the volume and cost increase, and the performance of the gradient system cannot be optimized to the greatest extent, and the performance of the system cannot be maximized

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