Performance improvement of magneto-acousto-electrical tomography for biological tissues with sinusoid-Barker coded excitation  

作　　者：Zheng-Feng Yu Yan Zhou Yu-Zhi Li Qing-Yu Ma Ge-Pu Guol Juan Tu Dong Zhang 余正风;周;李禹志;马青玉;郭各朴;屠娟;章东(Jiangsu Provincial Engineering Laboratory of Audio Technology, School of Physics and Technology,Nanjing Normal University;Institute of Acoustics, Nanjing University)

机构地区：[1]Jiangsu Provincial Engineering Laboratory of Audio Technology,School of Physics and Technology,Nanjing Normal University,Nanjing 210023,China [2]Institute of Acoustics,Nanjing University,Nanjing 210093,China

出　　处：《Chinese Physics B》2018年第9期346-353,共8页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.11474166 and 11604156);the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20161013);the Postdoctoral Science Foundation of China(Grant No.2016M591874);the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(Grant No.KYCX17 1083);the Priority Academic Program Development of Jiangsu Provincial Higher Education Institutions,China

摘　　要：By combining magnetics, acoustics and electrics, the magneto-acoustic-electrical tomography（MAET） proves to possess the capability of differentiating electrical impedance variation and thus improving the spatial resolution. However,the signal-to-noise ratio（SNR） of the collected MAET signal is still unsatisfactory for biological tissues with low-level electrical conductivity. In this study, the formula of MAET measurement with sinusoid-Barker coded excitation is derived and simplified for a planar piston transducer. Numerical simulations are conducted for a four-layered gel phantom with the 13-bit sinusoid-Barker coded excitation, and the performances of wave packet recovery with side-lobe suppression are improved by using the mismatched compression filter, which is also demonstrated by experimentally measuring a three-layered gel phantom. It is demonstrated that comparing with the single-cycle sinusoidal excitation, the amplitude of the driving signal can be reduced greatly with an SNR enhancement of 10 dB using the 13-bit sinusoid-Barker coded excitation. The amplitude and polarity of the wave packet filtered from the collected MAET signal can be used to achieve the conductivity derivative at the tissue boundary. In this study, we apply the sinusoid-Barker coded modulation method and the mismatched suppression scheme to MAET measurement to ensure the safety for biological tissues with improved SNR and spatial resolution, and suggest the potential applications in biomedical imaging.By combining magnetics, acoustics and electrics, the magneto-acoustic-electrical tomography（MAET） proves to possess the capability of differentiating electrical impedance variation and thus improving the spatial resolution. However,the signal-to-noise ratio（SNR） of the collected MAET signal is still unsatisfactory for biological tissues with low-level electrical conductivity. In this study, the formula of MAET measurement with sinusoid-Barker coded excitation is derived and simplified for a planar piston transducer. Numerical simulations are conducted for a four-layered gel phantom with the 13-bit sinusoid-Barker coded excitation, and the performances of wave packet recovery with side-lobe suppression are improved by using the mismatched compression filter, which is also demonstrated by experimentally measuring a three-layered gel phantom. It is demonstrated that comparing with the single-cycle sinusoidal excitation, the amplitude of the driving signal can be reduced greatly with an SNR enhancement of 10 dB using the 13-bit sinusoid-Barker coded excitation. The amplitude and polarity of the wave packet filtered from the collected MAET signal can be used to achieve the conductivity derivative at the tissue boundary. In this study, we apply the sinusoid-Barker coded modulation method and the mismatched suppression scheme to MAET measurement to ensure the safety for biological tissues with improved SNR and spatial resolution, and suggest the potential applications in biomedical imaging.

关 键 词：magneto-acousto-electrical tomography sinusoid-Barker coded excitation mismatched compression filter side lobe suppression 

分 类 号：TN713[电子电信—电路与系统] R318[医药卫生—生物医学工程]