Prepolarization coil current control system and control method for low-field nuclear magnetic resonance

A low-field nuclear magnetic resonance and control system technology, applied in current collectors, electric vehicles, electrical components, etc., can solve problems such as interference with imaging gradient fields, damage to IGBT switch tubes, and affecting imaging effects, and achieve the effect of ensuring safe use
CN109980743BActive Publication Date: 2020-12-29NAT UNIV OF DEFENSE TECH +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
NAT UNIV OF DEFENSE TECH
Publication Date
2020-12-29

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Abstract

The invention discloses a pre-polarization coil current control system for low-field nuclear paramagnetic resonance and a control method thereof. The control system comprises a power supply, a pre-polarization coil, a charging protection circuit, a bootstrap circuit and a bridge type symmetrical driving circuit, wherein the charging protection circuit and the bootstrap circuit are connected in series and form a loop with the power supply; the bridge type symmetrical driving circuit comprises four IGBT switch tubes connected in parallel with a capacitor; the four IGBT switch tubes form a symmetrical full-bridge structure so as to realize the switching-on and switching-off of current of the pre-polarization coil; and the pre-polarization coil is connected among the four IGBT switch tubes. When the bridge type symmetrical driving circuit is switched off, the self inductance current of the pre-polarization coil charges the capacitor group, so that the capacitor group generates the potential much higher than the power supply voltage and exerts the potential onto the pre-polarization coil, so that the current drop speed of the pre-polarization coil is continuously accelerated; and the fast switching-off of the current of the pre-polarization coil is realized.
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Description

technical field

[0001] The invention relates to the technical field of low-field nuclear magnetic resonance, in particular to a prepolarization coil current control system and control method for low-field nuclear magnetic resonance. Background technique

[0002] Magnetic resonance imaging (MRI) has a good ability to distinguish soft tissues, and is widely used in biology, medicine and other fields, and has become a powerful means of clinical diagnosis.

[0003] The current common high-field magnetic resonance imaging system (MRI) has been pursuing a higher main magnetic field strength B0 field strength, but this solution faces difficulties such as high cost and strict hardware requirements, and there are also problems that it is not suitable for special patients ; In contrast, the B0 field strength of the extremely low-field MRI system is low, and has the advantages of simple structure and low cost, and existing experiments have also shown that compared with high-field, diff...

Claims

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