A5051452480- Advanced MRI Techniques and Applications
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Advanced X-ray Imaging Techniques
- MRI in cancer diagnosis
- Soft Robotics and Applications
- Magnetic Field Sensors Techniques
- Wireless Power Transfer Systems
- Gastrointestinal Bleeding Diagnosis and Treatment
- Particle Accelerators and Free-Electron Lasers
- Electrical and Bioimpedance Tomography
- Advanced NMR Techniques and Applications
- Medical Imaging Techniques and Applications
- NMR spectroscopy and applications
- Micro and Nano Robotics
- Physics of Superconductivity and Magnetism
- Matrix Theory and Algorithms
- Advanced Neuroimaging Techniques and Applications
- Magnetic Properties and Applications
- Numerical methods in inverse problems
- Non-Destructive Testing Techniques
- Gastrointestinal disorders and treatments
Beijing University of Technology
2021-2024
Institute of Electrical Engineering
2016-2020
Chinese Academy of Sciences
2016-2020
University of Chinese Academy of Sciences
2018-2020
Magnetic field shimming of the magnet is a routine practice in magnetic resonance imaging (MRI) system. For clinically-used 1.5 T or 3 MRI superconducting magnets, it generally straightforward to achieve desired uniformity with passive shim technique. In comparison, shims higher efficiency are usually introduced combination satisfy requirement for ultrahigh magnets (≥7 Tesla). However, involves complex winding structure and low-temperature environment, bringing considerable engineering...
In this paper, a novel active shimming method is proposed to minimize the shim coil-magnet and coil-shim coil magnetic couplings simultaneously. standard superconducting designs, each usually designed individually correct specific field harmonic components of inhomogeneous without considering among coils main magnet. particular, strong interaction zonal magnet can lead series problems, like drift field, instability homogeneity, even destruction coils. decoupling techniques for reducing...
Magnetic navigation capsule endoscopy (MNCE) has been widely used for gastric examination because of its advantages high accuracy, speed, and minimal injury. However, the insufficient driving force single control strategy currently commercialized products have become challenges applying in active inspection intestinal tract. To solve these problems, based on existing cardiac interventional magnetic system, MNCE system with a dual-joystick method is proposed, which can achieve manipulation...
In planar magnetic resonance imaging (MRI) systems, gradient coils are usually placed within a very limited space owing to the physical constraints of small gap size (pole-pole) distance permanent magnet. Typically, unshielded or partially shielded design scheme is adopted generate required fields with reduced system costs. However, non-fully can induce large eddy currents on surrounding metal structures, including magnet poles, that significantly impact performance. This paper elaborates...
In this paper, a set of novel whole-body gradient coils is designed for cylindrical magnetic resonance imaging (MRI) systems. For the sake high coil efficiency, design scheme focuses on volume occupied by patient, discounting large space under patient bed that unused during imaging. To further improve performance, are an unconventional, hybrid cylindrical-planar structure, where primary arranged chord-truncated former while shielding remain assemblies. new configuration, layers make best...
Abstract In Magnetic Resonance Imaging ( MRI ) equipment, a set of shim coils are designed to generate specific magnetic fields, thus eliminating harmonic components field obtain high level homogeneous within the region interesting ROI ). electromagnetic design process, in order produce desired field, deviation between calculated coil and theoretical is treated as kind traditional objective functions optimize distribution current density on surface skeleton. However, such function ill‐posed...
Insertable head gradient coils offer significant advantages such as high strength and fast switching speed owing to shorter distances the target region of interest than whole-body cylindrical coils. To produce superior performance, local coil is typically designed with an asymmetric configuration accommodate both shoulders a patient, leading tough dimensional constraints practical limits implementation. In this paper, we propose new cone-shaped model improve performance mitigate patient...
With few exceptions, a fresh magnetic resonance imaging (MRI) scanner may fail to achieve the field specifications, due existence of engineering errors or surrounding ferromagnetic materials. Excellent homogeneity is one most important criteria for quality; therefore, shimming technique must be employed bring within MRI requirements. The commonly used method passive (PS), which utilizes shim pieces (iron pieces) with different thickness in specific positions generate “corrective” field. In...
In magnetic resonance imaging (MRI), pulsed gradient fields induce eddy currents in surrounding conducting components of the MRI scanner. These distort image and introduce thermal load cryostat. Ohmic heating superconducting magnet due to changes operating temperature magnet, which can lead system quench. Numerical simulation these current is important compensate/control their adverse effects. this paper, a coupled circuit network method outlined model that induced by z-gradient coil....
Magnetic resonance imaging (MRI) has become one of the most powerful tools in modern medical diagnosis and interventional therapy. It can achieve very fast scanning due to synchronization time space under high field with homogeneity. High stability improve ratio signal noise resolution. an important diagnostic tool early stages cancer, evaluation efficacy treatment high-risk surgery, neuroscience, molecular imaging. On other hand, recent years, development openness magnets combine MRI...
In this paper, we present a novel nonlinear optimization algorithm for designing shim coil system, especially high-order axial coil, magnetic resonance imaging（MRI) system. an MRI equipment, in order to eliminate higher-order harmonic components of the field within volume interest（VOI), passive shimming（PS) is adopted traditional methods. However, such method suitable global shimming with low accuracy and poor target. Active shimming（AS) makes up shortcomings from PS set coils which are...
Gradient coil is an essential component of a magnetic resonance imaging (MRI) scanner. To achieve high spatial resolution and speed, high-efficiency gradient with slew rate required. In consideration the safety comfort patient, mechanical stability, acoustic noise peripheral nerve stimulation (PNS) are also need to be concerned for practical use. our previous work, whole-body set hybrid cylindrical-planar structure has been presented, which offers significantly improved performances. this we...
Passive shimming optimizations usually contain constrain condition about the maximum number of shim-piece on position where shim-pieces may be placed at, but papers do not involve how to set shim-piece. In traditional optimization method, is into a same constant. But, in this paper, determined according its and requirement magnetic field uniformity. By comparison these two methods, method can obtain better result which has smaller error with accurate calculation The numerical simulation open...
Magnetic navigation capsule endoscopy (MNCE) is considered to be an important means realize the controllable and precise examination of (CE) in unstructured gastrointestinal (GI) tract. For current magnetic system (MNS), due limitation workspace, driving force, control method CE, only clinical application stomach has been realized, whereas other parts GI tract still experimental stage. More preclinical studies are needed achieve multisite tract.Based on MNS (Supiee) developed laboratory,...
In a magnetic resonance imaging system, the field homogeneity plays decisive role on image quality. As an effective technique, passive shimming (PS) uses ferromagnetic material (shim pieces) to eliminate impurity in area. existing PS algorithms, most attempt efficiently find continuous solutions using standard linear programming (LP). However, discrete solution has be used practice. Direct rounding off of may lead unacceptable loss. theory, integer (IP) can solution, however, it usually...
For extremely high field magnets, the low-temperature superconducting/high-temperature superconducting (LTS/HTS) structure is an efficient and economical solution. In LTS/HTS magnet system, LTS background deeply mutual inductance coupled with HTS insert magnet. A sudden quench may potentially destroy double pancakes (DPs) of because induced current resulting additional electromagnetic stress. To improve safety stability this article proposed a new passive protecting scheme system. scheme,...