摘要
Lorentz force electrical impedance tomography(LFEIT)inherits the merit of high resolution by ultrasound stimulation and the merit of high contrast through electromagnetic field detection.To reduce the instantaneous peak power of the stimulating signal to the transducer,the sinusoidal pulse and step-frequency technique is investigated in LFEIT.The theory of application of step-frequency technique in LFEIT is formulated with the direct demodulation method and the in-phase quadrature demodulation method.Compared with the in-phase quadrature demodulation method,the direct demodulation method has simple experimental setup but could only detect half of the range.Experiments carried out with copper foils confirmed that LFEIT using the step-frequency technique could detect the electrical conductivity variations precisely,which suggests an alternative method of realization of LFEIT.
作者
Zhi-Shen Sun
Guo-qiang Liu
Hui Xia
孙直申;刘国强;夏慧(Institute of Electrical Engineering,Chinese Academy of Sciences,Beijing 100190;University of Chinese Academy of Sciences,Beijing 100049;Univ Lyon,Universite Claude Bernard Lyon 1,Centre Leon Berard,INSERM,LabTAU UMR1032,LYON F-69003,France)
基金
Supported by the National Natural Science Foundation of China under Grant Nos 51137004 and 61427806
the Scientific Instrument and Equipment Development Project of Chinese Academy of Sciences under Grant No YZ201507
the China Scholarship Council Program under Grant No 201604910849
