Journal of South China University of Technology(Natural Science Edition) ›› 2022, Vol. 50 ›› Issue (12): 142-150.doi: 10.12141/j.issn.1000-565X.210752

Special Issue: 2022年电子、通信与自动控制

• Electronics, Communication & Automation Technology • Previous Articles    

Blind Source Separation Electrical Characteristics Extraction Method of Surface Electrical Impedance Myography Mixed Signals

YAN Hongli1 HUANG Linnan1 GAO Yueming1 VASIĆ Željka Lučev2 CIFREK Mario2   

  1. 1.College of Physical and Information Engineering/ Fujian Key Lab of Medical Instrumentation and Pharmaceutical Technology,Fuzhou University,Fuzhou 350108,Fujian,China
    2.Faculty of Electrical Engineering and Computing,University of Zagreb,Zagreb 10436,Croatia
  • Received:2021-12-01 Online:2022-12-25 Published:2022-07-29
  • Contact: 高跃明(1982-),男,博士,研究员,博士生导师,主要从事生物电磁和生物医学信号检测研究。 E-mail:fzu-gym@gmail.com.
  • About author:严洪立(1992-),男,博士生,主要从事智能图像与医学信息处理研究。E-mail:yan-hongli@foxmail.com.
  • Supported by:
    the National Key R&D Project of China(2022YFE0115500);the Regular Intergovernmental Exchange Project of the Ministry of Science and Technology(GKW [2019] No.16) and the Science and Technology Planning Project of Fujian Province(2021I0005)

Abstract:

Surface electrical impedance myography (sEIM) is important for evaluating muscle imbalance and muscle diseases. The mixed signals of impedance in the subcutaneous multilayer tissue captured by surface electrodes contain diverse-redundant components. Taking the mixed signals captured by sEIM as the blind signals and the muscle layer impedance as the source signal, this paper proposed a method for separating muscle layer impe-dance based on the impedance equivalent analysis and blind source separation, in order to improve the sensitivity of sEIM detecting changes in target muscle state. Firstly, a limb multilayer cylindrical finite element model for simulation was constructed. Secondly, a sensitivity method was employed to calculate the impedance contribution of each tissue layer for excluding redundant weak signals, which was equated to a blind source separation problem targeting the muscle layer. Finally, the separation effects of independent component analysis, principal component analysis, and equivariant adaptive separation via independence (EASI) were compared by numerical simulation and in vivo experiments to obtain the optimal solution and verify its feasibility. The results show that the correlation coefficient is above 0.98, the noise immunity is approximately 0.8, and the error cross talking (ECT) converges to 0.876 using the EASI-based method for separating muscle layer impedance. The separated muscle layer impedance in the in vivo experiments is consistent with the law of human impedance characteristics, indicating the method for separating muscle layer impedance with EASI can better enhance the sensitivity of sEIM to detect changes in the target muscle state.

Key words: electrical impedance myography, bioimpedance, blind source separation, finite element method, muscle

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