The existing wireless power transfer(WPT)systems for gastrointestinal capsule robot have the prob-lems of small coupling coefficient and low power transmission efficiency(PTE).The reasons are due to the long distance ...The existing wireless power transfer(WPT)systems for gastrointestinal capsule robot have the prob-lems of small coupling coefficient and low power transmission efficiency(PTE).The reasons are due to the long distance between the transmitting coil and the receiving coil and the large difference in size.A new type of WPT system is designed,which uses three sets of small coil pairs to form a power supply unit(PSU),and utilizes multiple PSUs to form a multi-coil WPT system.Compared with single-coil system,the multi-coil system can achieve higher power utilization by switching between PSUs,instead of opening all PSUs.ANSYS Maxwell is used to perform finite element modeling on the PSU,analyzing the characteristics of the transmitting magnetic field.The results of the experiment show that when the distance between the small coil pairs in the PSU is 180mm,the magnetic field has relatively good uniformity,and the magnetic strength change relative to the center point is less than 5%.The average received power of the system is greater than 800mW,and the PTE is up to 5.1%.展开更多
The Energy Climate Package is the EU response to the Global Warming Challenge.Induction heating processes can contribute to the energy saving goal:20%saving within 2020.European induction manufacturer already propose ...The Energy Climate Package is the EU response to the Global Warming Challenge.Induction heating processes can contribute to the energy saving goal:20%saving within 2020.European induction manufacturer already propose many efficient solutions at industrial scale.To improve induction devices for an always better energy efficiency, EDF R&D set up a French cooperative project called ISIS with a financial support of the French National Research Agency.Its objective is to promote induction heating as Best Available Technology(BAT)and to develop innovative solutions to increase its efficiency.The ISIS innovations concern the electroheat conversion of induction devices(auto-adaptive multi-coil power supply,low losses coils)and the recovering of fatally lost energy.This paper shows the mid-term results of this project.Firsts control algorithms were successfully tested on a 100 kW 3-coil power supply.A homogenization technique is proposed to model a multi-strand coil.A heat recovery test bench is build and equipped with a PFC control loop to fit with the production fluctuations.展开更多
Magnetorheological(MR) cell with multi-coil was designed to enlarge the range of controllable transmission torque by increasing the effective length. Individual input current was proposed to maximize its potential for...Magnetorheological(MR) cell with multi-coil was designed to enlarge the range of controllable transmission torque by increasing the effective length. Individual input current was proposed to maximize its potential for reducing power consumption and generating large yield stress. Finite element analysis was performed to analyze magnetic field distribution, based on which a prototype MR cell was fabricated and tested to investigate the performance of various combinations of individual input currents. A good correlation was identified between experimental results and FEA predications. The results show that the power consumption can be reduced to 42.4%, maintaining large transmission torque, by distributing the total current(2 A) to three individual magnetic coils. In addition, optimal results of four input currents considering a multi-objective function are obtained by changing the weighting factor λ. The advantage of this design, such as lower power consumption and more control flexibility, makes it more competitive in engineering applications that require large energy consumption.展开更多
High magnetic field homogeneity is critical for magnetic resonance imaging(MRI),functional MRI,and magnetic resonance spectroscopy(MRS)applications.B_(0)inhomogeneity during MR scans is a long-standing problem resulti...High magnetic field homogeneity is critical for magnetic resonance imaging(MRI),functional MRI,and magnetic resonance spectroscopy(MRS)applications.B_(0)inhomogeneity during MR scans is a long-standing problem resulting from magnet imperfections and site conditions,with the main issue being the inhomogeneity across the human body caused by differences in magnetic susceptibilities between tissues,resulting in signal loss,image distortion,and poor spectral resolution.Through a combination of passive and active shim techniques,as well as technological advances employing multi-coil techniques,optimal coil design,motion tracking,and real-time modifications,improved field homogeneity and image quality have been achieved in MRI/MRS.The integration of RF and shim coils brings a high shim efficiency due to the proximity of participants.This technique will potentially be applied to high-density RF coils with a high-density shim array for improved B_(0)homogeneity.Simultaneous shimming and image encoding can be achieved using multi-coil array,which also enables the development of novel encoding methods using advanced magnetic field control.Field monitoring enables the capture and real-time compensation for dynamic field perturbance beyond the static background inhomogeneity.These advancements have the potential to better use the scanner performance to enhance diagnostic capabilities and broaden applications of MRI/MRS in a variety of clinical and research settings.The purpose of this paper is to provide an overview of the latest advances in B_(0)magnetic field shimming and magnetic field control techniques as well as MR hardware,and to emphasize their significance and potential impact on improving the data quality of MRI/MRS.展开更多
基金the National Natural Science Founda-tion of China(Nos.61673271 and 81971767)the Shang-hai Research Project(Nos.19441910600,19441913800 and 19142203800)the Project of Institute of Medical Robotics,Shanghai Jiao Tong University(No.IMR2018KY05)。
文摘The existing wireless power transfer(WPT)systems for gastrointestinal capsule robot have the prob-lems of small coupling coefficient and low power transmission efficiency(PTE).The reasons are due to the long distance between the transmitting coil and the receiving coil and the large difference in size.A new type of WPT system is designed,which uses three sets of small coil pairs to form a power supply unit(PSU),and utilizes multiple PSUs to form a multi-coil WPT system.Compared with single-coil system,the multi-coil system can achieve higher power utilization by switching between PSUs,instead of opening all PSUs.ANSYS Maxwell is used to perform finite element modeling on the PSU,analyzing the characteristics of the transmitting magnetic field.The results of the experiment show that when the distance between the small coil pairs in the PSU is 180mm,the magnetic field has relatively good uniformity,and the magnetic strength change relative to the center point is less than 5%.The average received power of the system is greater than 800mW,and the PTE is up to 5.1%.
基金Item Sponsored by French Research National Agency (ANR) Through "Efficacite Energetique et Reduction des Emissions de CO_2 Dans les Systemes Industriels" Program(Project ISIS n°ANR-09-EESI-004)
文摘The Energy Climate Package is the EU response to the Global Warming Challenge.Induction heating processes can contribute to the energy saving goal:20%saving within 2020.European induction manufacturer already propose many efficient solutions at industrial scale.To improve induction devices for an always better energy efficiency, EDF R&D set up a French cooperative project called ISIS with a financial support of the French National Research Agency.Its objective is to promote induction heating as Best Available Technology(BAT)and to develop innovative solutions to increase its efficiency.The ISIS innovations concern the electroheat conversion of induction devices(auto-adaptive multi-coil power supply,low losses coils)and the recovering of fatally lost energy.This paper shows the mid-term results of this project.Firsts control algorithms were successfully tested on a 100 kW 3-coil power supply.A homogenization technique is proposed to model a multi-strand coil.A heat recovery test bench is build and equipped with a PFC control loop to fit with the production fluctuations.
基金Projects(51175265,51305207)supported by the National Natural Science Foundation of China
文摘Magnetorheological(MR) cell with multi-coil was designed to enlarge the range of controllable transmission torque by increasing the effective length. Individual input current was proposed to maximize its potential for reducing power consumption and generating large yield stress. Finite element analysis was performed to analyze magnetic field distribution, based on which a prototype MR cell was fabricated and tested to investigate the performance of various combinations of individual input currents. A good correlation was identified between experimental results and FEA predications. The results show that the power consumption can be reduced to 42.4%, maintaining large transmission torque, by distributing the total current(2 A) to three individual magnetic coils. In addition, optimal results of four input currents considering a multi-objective function are obtained by changing the weighting factor λ. The advantage of this design, such as lower power consumption and more control flexibility, makes it more competitive in engineering applications that require large energy consumption.
基金supported by the National Institute of Neurological Disorders and Stroke(NINDS)and the National Institutes of Health(NIH)grants R01NS121544 and R01HL156818Additionally,support was provided by NIH SBIR grant R43NS120795+1 种基金We acknowledge data collection and sharing from the project funded by the Frontotemporal Lobar Degeneration Neuroimaging Initiative(National Institutes of Health Grant R01 AG032306)Hsin-Jung Yang and Hui Han hold equity in Lucidity Medical LLC.
文摘High magnetic field homogeneity is critical for magnetic resonance imaging(MRI),functional MRI,and magnetic resonance spectroscopy(MRS)applications.B_(0)inhomogeneity during MR scans is a long-standing problem resulting from magnet imperfections and site conditions,with the main issue being the inhomogeneity across the human body caused by differences in magnetic susceptibilities between tissues,resulting in signal loss,image distortion,and poor spectral resolution.Through a combination of passive and active shim techniques,as well as technological advances employing multi-coil techniques,optimal coil design,motion tracking,and real-time modifications,improved field homogeneity and image quality have been achieved in MRI/MRS.The integration of RF and shim coils brings a high shim efficiency due to the proximity of participants.This technique will potentially be applied to high-density RF coils with a high-density shim array for improved B_(0)homogeneity.Simultaneous shimming and image encoding can be achieved using multi-coil array,which also enables the development of novel encoding methods using advanced magnetic field control.Field monitoring enables the capture and real-time compensation for dynamic field perturbance beyond the static background inhomogeneity.These advancements have the potential to better use the scanner performance to enhance diagnostic capabilities and broaden applications of MRI/MRS in a variety of clinical and research settings.The purpose of this paper is to provide an overview of the latest advances in B_(0)magnetic field shimming and magnetic field control techniques as well as MR hardware,and to emphasize their significance and potential impact on improving the data quality of MRI/MRS.
