In-Vivo Electrical Impedance Measurement in Mastoid Bone

dc.contributor.authorWyss Balmer, Thomas
dc.contributor.authorAnsó, Juan
dc.contributor.authorMuntane, Enric
dc.contributor.authorGavaghan, Kate
dc.contributor.authorWeber, Stefan
dc.contributor.authorStahel, Andreas
dc.contributor.authorBüchler, Philippe
dc.description.abstractNerve 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.
dc.identifier.citationAnnals of Biomedical Engineering, vol. 45 (4), pp. 1122-1132
dc.identifier.issn0090-6964, 1573-9686
dc.subjectFacial nerve monitoring, Resistivity, Cochlear implant, Nerve, preservation, human trabecular bone, direct cochlear access, facial-nerve, electrode, polarization, mechanical-properties, biological-materials, surgery, implantation, stimulation, model, Engineering
dc.titleIn-Vivo Electrical Impedance Measurement in Mastoid Bone
dc.typeJournal Article
dc.type.csemresearchareasDigital Health