Journal of Korea Society of Industrial Information Systems (한국산업정보학회논문지)

Korea Society of Industrial Information Systems (한국산업정보학회)
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Characteristics of Bio-impedance for Implantable Electrode Design in Human Skin

인간 피부에 삽입형 전극설계를 위한 생체임피던스 특성

  • 김민수 (경운대학교 항공정보통신공학과) ;
  • 조영창 (경운대학교 항공정보통신공학과)
  • Received : 2014.07.10
  • Accepted : 2014.08.18
  • Published : 2014.08.30
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Abstract

Electrode contact resistance is a crucial factor in physiological measurements and can be an accuracy limiting factor to perform electrical impedance measurements. The electrical bio-impedance values can be calculated by the conductivity and permittivity of underlying tissue using implant electrode in human skin. In this study we focus on detecting physiological changes in the human skin layers such as the sebum layer, stratum corneum layer, epidermis layer, dermis layer, subcutaneous fat and muscle. The aim of this paper is to obtain optimal design for implantable electrode at subcutaneous fat layer through the simulation by finite element methods(FEM). This is achieved by evaluating FEM simulations geometrically for different electrodes in length(50 mm, 70 mm), in shape(rectangle, round square, sexangle column), in material(gold) and in depth(22.325 mm) based on the information coming from the subcutaneous fat layer. In bio-impedance measurement experiments, according to electrode shapes and applied voltage, we have ascertained that there was the highest difference of bio-impedance in subcutaneous fat layer. The methodology of simulation can be extended to account for different electrode designs as well as more physical phenomena that are relevant to electrical impedance measurements of skin and their interpretation.

전극 접촉저항은 생리학적 측정에 중대한 인자이며, 전기적 임피던스 측정을 수행할 때 정확성에 제한적 요인이 될 수 있다. 생체전기임피던스 값들은 인간피부에 삽입되는 전극을 이용하여 하부 조직의 도전율과 유전율에 의해서 계산할 수 있다. 본 연구에서는 피지, 각질층, 표피층, 진피, 피하조직 및 근육층의 인체 피부의 생리적 변화를 검출하는데 주안점을 두고 있으며, 피하조직에 삽입되는 전극의 최적설계를 위해 유한요소법을 사용하였다. 이를 위해 전극의 길이(50 mm, 70 mm), 재질(금), 모양(직사각형, 둥근사각, 육각기둥) 및 깊이(22.325 mm)에 따른 전극설계의 차이를 유한요소법을 통해 피하조직 층으로부터 얻어지는 정보를 바탕으로 기하학적으로 평가하였다. 생체임피던스 실험에서 전극모양과 인가전압에 따라서 피하조직에서 생체임피던스 차이가 가장 크게 나타남을 확인하였다. 본 연구의 모의실험은 피부의 전기적 임피던스 측정과 해석에 관한 물리적 현상뿐만 아니라 다른 형태의 전극 설계에 관한 특성들을 설명할 수 있을 것이다.

Keywords

References

  1. Y. Cho, M. Kim, J. Yoon, "A study on the electrical difference for the limbs and thoracic impedance using real-time bio-impedance measurement system," J. Korea Industr. Syst. Res. Vol. 18, No. 6, pp. 9-16, 2013. https://doi.org/10.9723/jksiis.2013.18.6.009
  2. O. Martinsen, S. Grimnes and J. Karlwen, "Electrical methods for skin moisture assessment," Skin Pharmacol., Vol. 8, No. 5, pp. 237-245, 1995. https://doi.org/10.1159/000211353
  3. S.W. Park, J.W. Park, "Skin Region Extraction using Multi-layer Neural Network and Skin Color Moedel", Korea Industr. Syst. Res, Vol. 16, No.2, pp.31-38, 2011.
  4. M. Sawan, Y Laaziri, F. Mounaim, E. Elzayat, J. Coros and M. Elhilali, "Electrode tissues interface: modeling and experimental validation," Biomed. Master., Vol. 2, pp. S7-S15, 2007. https://doi.org/10.1088/1748-6041/2/1/S02
  5. J. Nasehi, T. Oh, C. Jin, A. Thiagalingam and A. McEwan, "Evaluation of different stimulation and measurement patterns based on internal electrode," Comput. in Biolo. and Med., Vol. 42, No. 11, pp. 1122-1132, 2012. https://doi.org/10.1016/j.compbiomed.2012.09.004
  6. M. Jolley et al., "Finite element modeling of subcutaneous implantable defibrillator electrodes in an adult torso," Heart Rhythm, Vol. 7, No. 5, pp. 692-698, 2010. https://doi.org/10.1016/j.hrthm.2010.01.030
  7. A. Searle and L. Kirkup, "A direct comparison of wet, dry and insulating bioelectric recording electrodes," Physiol. Meas. Vol. 21, No. 2, pp. 271-283, 2000. https://doi.org/10.1088/0967-3334/21/2/307
  8. C. Roberto, H. Philip, T. Craig and M. Alistair, "Electrode contact impedance sensitivity to variations in geometry," Physiol. Meas., Vol. 33, pp. 817-830, 2012. https://doi.org/10.1088/0967-3334/33/5/817
  9. J. Van Duk, M. Lowery, B. Lapatki and D. Stegeman, "Evidence of potential Averaging over the Finite Surface of a Bioelectric Surface Electrode," Annals of Biomed. Eng., Vol. 37, No. 6, pp. 1141-1151, 2009. https://doi.org/10.1007/s10439-009-9680-7
  10. X. Zh ao, Y. Kinouchi, E. Yasuno, D. Gao, T. Morimoto and M. Takeuchi, "A new method for noninvasive measurement of multilayer tissue conductivity and structure using divided electrodes," IEEE Tran. Biomed. Eng., Vol. 51, No. 2, 2004.
  11. S. Huclova, D. Baumann, M. Talary and J. Frohlich, "Sensitivity and specificity analysis of fringing field dielectric spectroscopy applied to a multilayer system modelling the human skin," Phys. Med. Biol. Vol. 56, No. 24, pp.7777-7793, 2011. https://doi.org/10.1088/0031-9155/56/24/007
  12. M.S. Kim, Y.C. Cho, S.T. Seo, C.S. Son, H.J. Park, Y.N. Kim, "A New Method for Non-Invasive Measurement of Skin in the Low Frequency Range," Health. Informat. Rese. Vol. 16, No. 3, pp. 143-148, 2010. https://doi.org/10.4258/hir.2010.16.3.143
  13. U. Birgersson, E. Birgersson, I. Nicander and S. Ollmar, "A methodology for extracting the electrical properties of human skin," Physiol. Meas., Vol. 34, No. 6, pp. 723-736, 2013. https://doi.org/10.1088/0967-3334/34/6/723
  14. S. Grimnes and O. Martinsen, "Bioimpedance and bioelectricity basics, "Academic Pres., 2000.