Electromagnetic Field Analysis of Signal Transmission Path and Electrode Contact Conditions in Human Body Communication

Human body communication (HBC) is a wireless communication method that uses the human body as part of the transmission medium. Electrodes are used instead of antennas, and the signal is transmitted by the electric current through the human body and by the capacitive coupling outside the human body. In this study, direction of electric field lines and direction of electric current through the human body were analyzed by the finite-difference time-domain method to clarify the signal path, which is not readily apparent from electric field strength distribution. Signal transmission from a transmitter on the subject’s wrist to an off-body receiver touched by the subject was analyzed for two types of transmitter electrode settings. When both the signal and ground electrodes were put in contact with the human body, the major return path consisted of capacitive coupling between the receiver ground and the human body, and the electric current through the human body that flowed back to the ground electrode of the transmitter. When the ground electrode was floating, the only return path was through the capacitive coupling of the floating ground. These results contribute to the better understanding of signal transmission mechanism of HBC and will be useful for developing HBC applications.

[1]  J.H. Hwang,et al.  Reverse effect of ground electrode on the signal loss of human body communication , 2008, 2008 IEEE Antennas and Propagation Society International Symposium.

[2]  Fukuro Koshiji,et al.  Input impedance analysis of a human body communication transmitter using a realistic human model and a simplified layered model , 2013 .

[3]  K. Fujii,et al.  A study on the receiving signal level in relation with the location of electrodes for wearable devices using human body as a transmission channel , 2003, IEEE Antennas and Propagation Society International Symposium. Digest. Held in conjunction with: USNC/CNC/URSI North American Radio Sci. Meeting (Cat. No.03CH37450).

[4]  Fukuro Koshiji,et al.  Evaluation of Ground Loop Through the Floor in Human Body Communication , 2017, Int. J. Wirel. Inf. Networks.

[5]  George Jie Yuan,et al.  Electric-Field Intrabody Communication Channel Modeling With Finite-Element Method , 2011, IEEE Transactions on Biomedical Engineering.

[6]  Yufei Zhao,et al.  The Modeling and Simulation of the Galvanic Coupling Intra-Body Communication via Handshake Channel , 2017, Sensors.

[7]  Bo Zhao,et al.  An Investigation on Ground Electrodes of Capacitive Coupling Human Body Communication , 2017, IEEE Transactions on Biomedical Circuits and Systems.

[8]  J.H. Hwang,et al.  Effects of ground electrode on signal transmission of human body communication using human body as transmission medium , 2006, 2006 IEEE Antennas and Propagation Society International Symposium.

[9]  Fukuro Koshiji,et al.  Electromagnetic field analysis of human body communication between wearable and stationary devices including the earth ground , 2014, 2014 International Conference on Electronics Packaging (ICEP).

[10]  Harinath Garudadri,et al.  Channel Modeling of Miniaturized Battery-Powered Capacitive Human Body Communication Systems , 2017, IEEE Transactions on Biomedical Engineering.

[11]  Abbas Jamalipour,et al.  Wireless Body Area Networks: A Survey , 2014, IEEE Communications Surveys & Tutorials.

[12]  German A. Alvarez-Botero,et al.  Characterization and Modeling of the Capacitive HBC Channel , 2015, IEEE Transactions on Instrumentation and Measurement.

[13]  Nozomi Haga,et al.  Equivalent Circuit of Intrabody Communication Channels Inducing Conduction Currents Inside the Human Body , 2013, IEEE Transactions on Antennas and Propagation.

[14]  Muhammad Irfan Kazim,et al.  An Efficient Full-Wave Electromagnetic Analysis for Capacitive Body-Coupled Communication , 2015 .

[15]  Yong-Xin Guo,et al.  Investigation and Modeling of Capacitive Human Body Communication , 2017, IEEE Transactions on Biomedical Circuits and Systems.

[16]  George Jie Yuan,et al.  Equation Environment Coupling and Interference on the Electric-Field Intrabody Communication Channel , 2012, IEEE Transactions on Biomedical Engineering.

[17]  Kai Zhang,et al.  A Finite-Element Simulation of Galvanic Coupling Intra-Body Communication Based on the Whole Human Body , 2012, Sensors.

[18]  Thomas G. Zimmerman,et al.  : Near-field , 2022 .

[19]  Alberto Fazzi,et al.  Human-centric connectivity enabled by body-coupled communications , 2009, IEEE Communications Magazine.

[20]  K. Fujii,et al.  Electric Field Distributions of Wearable Devices Using the Human Body as a Transmission Channel , 2007, IEEE Transactions on Antennas and Propagation.

[21]  Robert Simon Sherratt,et al.  A Survey on Wireless Body Area Networks for eHealthcare Systems in Residential Environments , 2016, Sensors.

[22]  Ken Sasaki,et al.  Intra-body data transmission for the personal area network , 2005 .