For a practical superconducting quantum interference device（SQUID） based measurement system,the Tesla/volt coefficient must be accurately calibrated.In this paper,we propose a highly efficient method of calibrating ...For a practical superconducting quantum interference device（SQUID） based measurement system,the Tesla/volt coefficient must be accurately calibrated.In this paper,we propose a highly efficient method of calibrating a SQUID magnetometer system using three orthogonal Helmholtz coils.The Tesla/volt coefficient is regarded as the magnitude of a vector pointing to the normal direction of the pickup coil.By applying magnetic fields through a three-dimensional Helmholtz coil,the Tesla/volt coefficient can be directly calculated from magnetometer responses to the three orthogonally applied magnetic fields.Calibration with alternating current（AC） field is normally used for better signal-to-noise ratio in noisy urban environments and the results are compared with the direct current（DC） calibration to avoid possible effects due to eddy current.In our experiment,a calibration relative error of about 6.89 × 10-4is obtained,and the error is mainly caused by the non-orthogonality of three axes of the Helmholtz coils.The method does not need precise alignment of the magnetometer inside the Helmholtz coil.It can be used for the multichannel magnetometer system calibration effectively and accurately.展开更多
Energy metabolism is fundamental for life.It encompasses the utilization of carbohydrates,lipids,and proteins for internal processes,while aberrant energy metabolism is implicated in many diseases.In the present study...Energy metabolism is fundamental for life.It encompasses the utilization of carbohydrates,lipids,and proteins for internal processes,while aberrant energy metabolism is implicated in many diseases.In the present study,using three-dimensional(3D)printing from polycarbonate via fused deposition modeling,we propose a multi-nuclear radiofrequency(RF)coil design with integrated 1H birdcage and interchangeable X-nuclei(^(2)H,^(13)C,^(23)Na,and^(31)P)single-loop coils for magnetic resonance imaging(MRI)/magnetic resonance spectroscopy(MRS).The single-loop coil for each nucleus attaches to an arc bracket that slides unrestrictedly along the birdcage coil inner surface,enabling convenient switching among various nuclei and animal handling.Compared to a commercial 1H birdcage coil,the proposed 1H birdcage coil exhibited superior signal-excitation homogeneity and imaging signal-to-noise ratio(SNR).For X-nuclei study,prominent peaks in spectroscopy for phantom solutions showed excellent SNR,and the static and dynamic peaks of in vivo spectroscopy validated the efficacy of the coil design in structural imaging and energy metabolism detection simultaneously.展开更多
目的胶囊内镜机器人受尺寸限制和安全性等因素的影响,传统锂电池或拖缆式供能已不能满足要求,如何提供有效的供能方式成为其发展的重大瓶颈。随着无线供能方式的提出,基于电磁感应的无线能量传输被视为一种有效解决该问题的供能方式。...目的胶囊内镜机器人受尺寸限制和安全性等因素的影响,传统锂电池或拖缆式供能已不能满足要求,如何提供有效的供能方式成为其发展的重大瓶颈。随着无线供能方式的提出,基于电磁感应的无线能量传输被视为一种有效解决该问题的供能方式。方法设计了一个在任意姿态下接收线圈均能高效稳定供能胶囊机器人的无线能量传输系统。首先设计了符合赫姆霍兹线圈结构的双螺线管对线圈作为发射线圈,再结合机器人结构特征设计新型的磁芯结构和绕线方式,构成新型三维正交接收线圈。最后在由发射线圈和体外控制电路组成的可调谐发射平台上进行了0~360°范围内系统有效接收效率的测试。结果该系统能量传输效率在线圈任意姿态不低于4.95%,解决了因接收线圈姿态变化导致的供能不足问题。结论在输入功率为10.88 W条件下能提供最少544 m W的能量,实验验证了该系统的可行性。展开更多
基金Project supported by the“Strategic Priority Research Program(B)”of the Chinese Academy of Sciences(Grant No.XDB04020200)the Shanghai Municipal Science and Technology Commission Project,China(Grant No.15DZ1940902)
文摘For a practical superconducting quantum interference device（SQUID） based measurement system,the Tesla/volt coefficient must be accurately calibrated.In this paper,we propose a highly efficient method of calibrating a SQUID magnetometer system using three orthogonal Helmholtz coils.The Tesla/volt coefficient is regarded as the magnitude of a vector pointing to the normal direction of the pickup coil.By applying magnetic fields through a three-dimensional Helmholtz coil,the Tesla/volt coefficient can be directly calculated from magnetometer responses to the three orthogonally applied magnetic fields.Calibration with alternating current（AC） field is normally used for better signal-to-noise ratio in noisy urban environments and the results are compared with the direct current（DC） calibration to avoid possible effects due to eddy current.In our experiment,a calibration relative error of about 6.89 × 10-4is obtained,and the error is mainly caused by the non-orthogonality of three axes of the Helmholtz coils.The method does not need precise alignment of the magnetometer inside the Helmholtz coil.It can be used for the multichannel magnetometer system calibration effectively and accurately.
基金This work was supported in part by the STI 2030-Major Projects(No.2021ZD0200401)the National Key Research and Development Program of China(No.2018YFA0701400)+3 种基金the National Natural Science Foundation of China(Nos.52277232,52293424,81701774,and 61771423)the Fundamental Research Funds for the Central Universities(Nos.226-2022-00136 and 226-2023-00125)the Zhejiang Provincial Natural Science Foundation of China(No.LR23E070001),the Key R&D Program of Jiangsu Province(No.BE2022049)the Key-Area R&D Program of Guangdong Province(No.2018B030333001),China.
文摘Energy metabolism is fundamental for life.It encompasses the utilization of carbohydrates,lipids,and proteins for internal processes,while aberrant energy metabolism is implicated in many diseases.In the present study,using three-dimensional(3D)printing from polycarbonate via fused deposition modeling,we propose a multi-nuclear radiofrequency(RF)coil design with integrated 1H birdcage and interchangeable X-nuclei(^(2)H,^(13)C,^(23)Na,and^(31)P)single-loop coils for magnetic resonance imaging(MRI)/magnetic resonance spectroscopy(MRS).The single-loop coil for each nucleus attaches to an arc bracket that slides unrestrictedly along the birdcage coil inner surface,enabling convenient switching among various nuclei and animal handling.Compared to a commercial 1H birdcage coil,the proposed 1H birdcage coil exhibited superior signal-excitation homogeneity and imaging signal-to-noise ratio(SNR).For X-nuclei study,prominent peaks in spectroscopy for phantom solutions showed excellent SNR,and the static and dynamic peaks of in vivo spectroscopy validated the efficacy of the coil design in structural imaging and energy metabolism detection simultaneously.
文摘目的胶囊内镜机器人受尺寸限制和安全性等因素的影响,传统锂电池或拖缆式供能已不能满足要求,如何提供有效的供能方式成为其发展的重大瓶颈。随着无线供能方式的提出,基于电磁感应的无线能量传输被视为一种有效解决该问题的供能方式。方法设计了一个在任意姿态下接收线圈均能高效稳定供能胶囊机器人的无线能量传输系统。首先设计了符合赫姆霍兹线圈结构的双螺线管对线圈作为发射线圈,再结合机器人结构特征设计新型的磁芯结构和绕线方式,构成新型三维正交接收线圈。最后在由发射线圈和体外控制电路组成的可调谐发射平台上进行了0~360°范围内系统有效接收效率的测试。结果该系统能量传输效率在线圈任意姿态不低于4.95%,解决了因接收线圈姿态变化导致的供能不足问题。结论在输入功率为10.88 W条件下能提供最少544 m W的能量,实验验证了该系统的可行性。
