Annals of Biomedical Engineering

, Volume 45, Issue 4, pp 1122–1132 | Cite as

In-Vivo Electrical Impedance Measurement in Mastoid Bone

  • Thomas Wyss BalmerEmail author
  • Juan Ansó
  • Enric Muntane
  • Kate Gavaghan
  • Stefan Weber
  • Andreas Stahel
  • Philippe Büchler


Nerve monitoring is a safety mechanism to detect the proximity between surgical instruments and important nerves during surgical bone preparation. In temporal bone, this technique is highly specific and sensitive at distances below 0.1 mm, but remains unreliable for distances above this threshold. A deeper understanding of the patient-specific bone electric properties is required to improve this range of detection. A sheep animal model has been used to characterize bone properties in vivo. Impedance measurements have been performed at low frequencies (<1 kHz) between two electrodes placed inside holes drilled into the sheep mastoid bone. An electric circuit composed of a resistor and a Fricke constant phase element was able to accurately describe the experimental measurements. Bone resistivity was shown to be linearly dependent on the inter-electrode distance and the local bone density. Based on this model, the amount of bone material between the electrodes could be predicted with an error of 0.7 mm. Our results indicate that bone could be described as an ideal resistor while the electrochemical processes at the electrode-tissue interface are characterized by a constant phase element. These results should help increasing the safety of surgical drilling procedures by better predicting the distance to critical nerve structures.


Facial nerve monitoring Resistivity Cochlear implant Nerve preservation 



This work is part of the HearRestore project, scientifically evaluated by the SNF, financed by the Swiss Confederation, and funded by


  1. 1.
    Ansó, J., C. Dür, K. Gavaghan, H. Rohrbach, N. Gerber, T. Williamson, E. M. Calvo, T. W. Balmer, C. Precht, D. Ferrario, M. S. Dettmer, K. M. Rösler, M. D. Caversaccio, B. Bell, and S. Weber. A neuromonitoring approach to facial nerve preservation during image-guided robotic cochlear implantation. Otol. Neurotol. 37:89–98, 2016.CrossRefPubMedGoogle Scholar
  2. 2.
    Ansó, J., C. Stahl, N. Gerber, T. M. Williamson, K. Gavaghan, M. Caversaccio, S. Weber, and B. Bell. Feasibility of using EMG for early detection of the facial nerve during robotic direct cochlear access. Otol. Neurotol. 35:545–554, 2014.CrossRefPubMedGoogle Scholar
  3. 3.
    Bell, B., N. Gerber, T. Williamson, K. Gavaghan, W. Wimmer, M. Caversaccio, and S. Weber. In vitro accuracy evaluation of image-guided robot system for direct cochlear access. Otol. Neurotol. 34:1284–1290, 2013.CrossRefPubMedGoogle Scholar
  4. 4.
    Bell, B., C. Stieger, N. Gerber, A. Arnold, C. Nauer, V. Hamacher, M. Kompis, L. Nolte, M. Caversaccio, and S. Weber. A self-developed and constructed robot for minimally invasive cochlear implantation. Acta Otolaryngol. 132:355–360, 2012.CrossRefPubMedGoogle Scholar
  5. 5.
    Bernardeschi, D., N. Meskine, N. AlOtaibi, R. Ablonczy, M. Kalamarides, A. B. Grayeli, and O. Sterkers. Continuous facial nerve stimulating burr for otologic surgeries. Otol. Neurotol. 32:1347–1351, 2011.CrossRefPubMedGoogle Scholar
  6. 6.
    Cordero, A., M. del mar Medina, A. Alonso, and T. Labatut. Stapedectomy in sheep: an animal model for surgical training. Otol. Neurotol. 32:742–747, 2011.CrossRefPubMedGoogle Scholar
  7. 7.
    Delgado, T. E., W. A. Bucheit, H. R. Rosenholtz, and S. Chrissian. Intraoperative monitoring of facila muscle evoked responses obtained by intracranial stimulation of the facila nerve: a more accurate technique for facila nerve dissection. Neurosurgery 4:418–421, 1979.CrossRefPubMedGoogle Scholar
  8. 8.
    Dong, C. C. J., D. B. Macdonald, R. Akagami, B. Westerberg, A. Alkhani, I. Kanaan, and M. Hassounah. Intraoperative facial motor evoked potential monitoring with transcranial electrical stimulation during skull base surgery. Clin. Neurophysiol. 116:588–596, 2005.CrossRefPubMedGoogle Scholar
  9. 9.
    Dralle, H., C. Sekulla, K. Lorenz, M. Brauckhoff, and A. Machens. Intraoperative monitoring of the recurrent laryngeal nerve in thyroid surgery. World J. Surg. 32:1358–1366, 2008.CrossRefPubMedGoogle Scholar
  10. 10.
    Gabriel, C., S. Gabriel, and E. Corthout. The dielectric properties of biological tissues: I. Literature survey. Phys. Med. Biol. 41:2231–2249, 1996.CrossRefPubMedGoogle Scholar
  11. 11.
    Geddes, L. A., C. P. Da Costa, and G. Wise. The impedance of stainless-steel electrodes. Med. Biol. Eng. 9:511–521, 1971.CrossRefPubMedGoogle Scholar
  12. 12.
    Geers, A. E., J. G. Nicholas, and A. L. Sedey. Language skills of children with early cochlear implantation. Ear Hear. 24:46S–58S, 2003.CrossRefPubMedGoogle Scholar
  13. 13.
    Gerber, N., B. Bell, K. Gavaghan, C. Weisstanner, M. Caversaccio, and S. Weber. Surgical planning tool for robotically assisted hearing aid implantation. Int. J. Comput. Assist. Radiol. Surg. 9:11–20, 2014.CrossRefPubMedGoogle Scholar
  14. 14.
    Gurr, A., T. Stark, G. Probst, and S. Dazert. The temporal bone of lamb and pig as an alternative in ENT-education. Laryngorhinootologie 89:17–24, 2010.CrossRefPubMedGoogle Scholar
  15. 15.
    Heman-Ackah, S. E., S. Gupta, and A. K. Lalwani. Is facial nerve integrity monitoring of value in chronic ear surgery? Laryngoscope 123:2–3, 2013.CrossRefPubMedGoogle Scholar
  16. 16.
    Kalvøy, H. Needle guidance in clinical applications based on electrical impedance. Ann. Biomed. Eng. 38:2371–2382, 2010.CrossRefPubMedGoogle Scholar
  17. 17.
    Kalvøy, H., L. Frich, S. Grimnes, O. G. Martinsen, P. K. Hol, and A. Stubhaug. Impedance-based tissue discrimination for needle guidance. Physiol. Meas. 30:129–140, 2009.CrossRefPubMedGoogle Scholar
  18. 18.
    Kalvøy, H., P. Høyum, S. Grimnes, and Ø. G. Martinsen. From impedance theory to needle electrode guidance in tissue. J. Phys. Conf. Ser. 224:12072, 2010.CrossRefGoogle Scholar
  19. 19.
    Kalvøy, H., G. K. Johnsen, O. G. Martinsen, and S. Grimnes. New method for separation of electrode polarization impedance from measured tissue impedance. Open Biomed. Eng. J. 5:8–13, 2011.CrossRefPubMedPubMedCentralGoogle Scholar
  20. 20.
    Kalvøy, H., C. Tronstad, B. Nordbotten, S. Grimnes, and Ø. G. Martinsen. Electrical impedance of stainless steel needle electrodes. Ann. Biomed. Eng. 38:2371–2382, 2010.CrossRefPubMedGoogle Scholar
  21. 21.
    Labadie, R. F., R. Balachandran, J. H. Noble, G. S. Blachon, J. E. Mitchell, F. A. Reda, B. M. Dawant, and J. M. Fitzpatrick. Minimally invasive image-guided cochlear implantation surgery: first report of clinical implementation. Laryngoscope 124:1915–1922, 2014.CrossRefPubMedPubMedCentralGoogle Scholar
  22. 22.
    Leonetti, J. P., G. J. Matz, P. G. Smith, and D. L. Beck. Facial nerve monitoring in otologic surgery: clinical indications and intraoperative technique. Ann. Otol. Rhinol. Laryngol. 99:911–918, 1990.CrossRefPubMedGoogle Scholar
  23. 23.
    Liboff, A. R., R. A. Rinaldi, L. S. Lavine, and M. H. Shamos. On electrical conduction in living bone. Clin. Orthop. Relat. Res. 106:330–335, 1975.CrossRefGoogle Scholar
  24. 24.
    Prass, R. Iatrogenic facial nerve injury: the role of facial nerve monitoring. Otolaryngol. Clin. North Am. 29:265–275, 1996.PubMedGoogle Scholar
  25. 25.
    Prass, R., and H. Lüders. Constant-current versus constant-voltage stimulation. Neurosurgery 62:622–623, 1985.Google Scholar
  26. 26.
    Schwan, H. Electrode polarization impedance and measurements in biological materials. Ann. N. Y. Acad. Sci. 148:191–209, 1968.CrossRefPubMedGoogle Scholar
  27. 27.
    Schwan, H. P. Linear and nonlinear electrode polarization and biological materials. Ann. Biomed. Eng. 20:269–288, 1992.CrossRefPubMedGoogle Scholar
  28. 28.
    Seibel, V. A. A., L. Lavinsky, and J. A. P. De Oliveira. Morphometric study of the external and middle ear anatomy in sheep: a possible model for ear experiments. Clin. Anat. 19:503–509, 2006.CrossRefPubMedGoogle Scholar
  29. 29.
    Sierpowska, J., M. A. Hakulinen, J. Töyräs, J. S. Day, H. Weinans, I. Kiviranta, J. S. Jurvelin, and R. Lappalainen. Interrelationships between electrical properties and microstructure of human trabecular bone. Phys. Med. Biol. 51:5289–5303, 2006.CrossRefPubMedGoogle Scholar
  30. 30.
    Sierpowska, J., M. A. Hakulinen, J. Töyräs, J. S. Day, H. Weinans, J. S. Jurvelin, and R. Lappalainen. Prediction of mechanical properties of human trabecular bone by electrical measurements. Physiol. Meas. 26:S119–S131, 2005.CrossRefPubMedGoogle Scholar
  31. 31.
    Sierpowska, J., M. J. Lammi, M. A. Hakulinen, J. S. Jurvelin, R. Lappalainen, and J. Töyräs. Effect of human trabecular bone composition on its electrical properties. Med. Eng. Phys. 29:845–852, 2007.CrossRefPubMedGoogle Scholar
  32. 32.
    Sierpowska, J., J. Töyräs, M. A. Hakulinen, S. Saarakkala, J. S. Jurvelin, and R. Lappalainen. Electrical and dielectric properties of bovine trabecular bone–relationships with mechanical properties and mineral density. Phys. Med. Biol. 48:775–786, 2003.CrossRefPubMedGoogle Scholar
  33. 33.
    Silverstein, H., and S. Rosenberg. Intraoperative facial nerve monitoring. Otolaryngol. Clin. North Am. 24:709–725, 1991.PubMedGoogle Scholar
  34. 34.
    Silverstein, H., E. Smouha, and R. Jones. Routine identification of the facial nerve using electrical stimulation during otological and neurotological surgery. Laryngoscope 98:726–730, 1988.CrossRefPubMedGoogle Scholar
  35. 35.
    Stecker, M. A review of intraoperative monitoring for spinal surgery. Surg. Neurol. Int. 3:174, 2012.CrossRefGoogle Scholar
  36. 36.
    Wanna, G. B., R. Balachandran, O. Majdani, J. Mitchell, and R. F. Labadie. Percutaneous access to the petrous apex in vitro using customized micro-stereotactic frames based on image-guided surgical technology. Acta Otolaryngol. 1–6, 2009.Google Scholar

Copyright information

© Biomedical Engineering Society 2016

Authors and Affiliations

  1. 1.Computational Biomechanics, ISTBUniversity of BernBernSwitzerland
  2. 2.ARTORG Center for Biomedical EngineeringUniversity of BernBernSwitzerland
  3. 3.Control and Sensing Systems Division, CSEMNeuchâtelSwitzerland
  4. 4.Mathematics, Bern University of Applied SciencesBielSwitzerland

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