Consensus Panel on a Cochlear Coordinate System Applicable in Histologic, Physiologic, and Radiologic Studies of the Human Cochlea

Hypothesis: An objective cochlear framework, for evaluation of the cochlear anatomy and description of the position of an implanted cochlear implant electrode, would allow the direct comparison of measures performed within the various subdisciplines involved in cochlear implant research. Background: Research on the human cochlear anatomy in relation to tonotopy and cochlear implantation is conducted by specialists from numerous disciplines such as histologists, surgeons, physicists, engineers, audiologists, and radiologists. To allow accurate comparisons between and combinations of previous and forthcoming scientific and clinical studies, cochlear structures and electrode positions must be specified in a consistent manner. Methods: Researchers with backgrounds in the various fields of inner ear research as well as representatives of the different manufacturers of cochlear implants (Advanced Bionics Corp., Med-El, Cochlear Corp.) were involved in consensus meetings held in Dallas, March 2005, and Asilomar, August 2005. Existing coordinate systems were evaluated, and requisites for an objective cochlear framework were discussed. Results: The consensus panel agreed upon a 3-dimensional, cylindrical coordinate system of the cochlea using the "Cochlear View" as a basis and choosing a z axis through the modiolus. The zero reference angle was chosen at the center of the round window, which has a close relationship to the basal end of the Organ of Corti. Conclusion: Consensus was reached on an objective cochlear framework, allowing the outcomes of studies from different fields of research to be compared directly.

[1]  G M Clark,et al.  Cochlear view: postoperative radiography for cochlear implantation. , 2000, The American journal of otology.

[2]  Mary Hardy,et al.  The length of the organ of Corti in man , 1938 .

[3]  Margaret W Skinner,et al.  In Vivo Estimates of the Position of Advanced Bionics Electrode Arrays in the Human Cochlea , 2007, The Annals of otology, rhinology & laryngology. Supplement.

[4]  Johan H. M. Frijns,et al.  The consequences of neural degeneration regarding optimal cochlear implant position in scala tympani: A model approach , 2006, Hearing Research.

[5]  G. Bredberg,et al.  Cellular pattern and nerve supply of the human organ of Corti. , 1968, Acta oto-laryngologica.

[6]  Ge Wang,et al.  Three-dimensional geometric modeling of the cochlea using helico-spiral approximation , 2000, IEEE Trans. Biomed. Eng..

[7]  Jean-Philippe Guyot,et al.  Measurements of electrode position inside the cochlea for different cochlear implant systems , 2005, Acta oto-laryngologica.

[8]  Patricia A. Leake,et al.  Frequency Map for the Human Cochlear Spiral Ganglion: Implications for Cochlear Implants , 2007, Journal for the Association for Research in Otolaryngology.

[9]  Johan H M Frijns,et al.  Multisection CT as a valuable tool in the postoperative assessment of cochlear implant patients. , 2005, AJNR. American journal of neuroradiology.

[10]  D. D. Greenwood Critical Bandwidth and the Frequency Coordinates of the Basilar Membrane , 1961 .

[11]  Bernard Fraysse,et al.  The Size of the Cochlea and Predictions of Insertion Depth Angles for Cochlear Implant Electrodes , 2006, Audiology and Neurotology.

[12]  W. Kalender,et al.  Determination of the position of nucleus cochlear implant electrodes in the inner ear. , 1994, The American journal of otology.

[13]  Margaret W. Skinner,et al.  Use of Computed Tomography Scans for Cochlear Implants , 2008, Journal of Digital Imaging.

[14]  G M Clark,et al.  Absolute identification of electric pulse rates and electrode positions by cochlear implant patients. , 1985, The Journal of the Acoustical Society of America.

[15]  L M Collins,et al.  Comparison of electrode discrimination, pitch ranking, and pitch scaling data in postlingually deafened adult cochlear implant subjects. , 1997, Journal of the Acoustical Society of America.

[16]  Graeme M. Clark,et al.  Pitch comparisons of acoustically and electrically evoked auditory sensations , 1996, Hearing Research.

[17]  W.A. Kalender,et al.  Unwrapping cochlear implants by spiral CT , 1996, IEEE Transactions on Biomedical Engineering.

[18]  A Frequency-Position Function for the Human Cochlear Spiral Ganglion , 2006, Audiology and Neurotology.

[19]  G. Wang,et al.  In vivo measures of cochlear length and insertion depth of nucleus cochlear implant electrode arrays. , 1998, The Annals of otology, rhinology & laryngology. Supplement.

[20]  D. D. Greenwood A cochlear frequency-position function for several species--29 years later. , 1990, The Journal of the Acoustical Society of America.

[21]  Luca Ferrarini,et al.  Anatomic Considerations of Cochlear Morphology and Its Implications for Insertion Trauma in Cochlear Implant Surgery , 2009, Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology.

[22]  A. Wright,et al.  Hair cell distributions in the normal human cochlea. , 1987, Acta oto-laryngologica. Supplementum.

[23]  H. Takahashi,et al.  Sexual dimorphism and development of the human cochlea. Computer 3-D measurement. , 1991, Acta oto-laryngologica.

[24]  G M Clark,et al.  Improved and simplified methods for specifying positions of the electrode bands of a cochlear implant array. , 1996, The American journal of otology.

[25]  Louise Loiselle,et al.  An Electric Frequency-to-place Map for a Cochlear Implant Patient with Hearing in the Nonimplanted Ear , 2007, Journal for the Association for Research in Otolaryngology.

[26]  G M Clark,et al.  Radiologic evaluation of multichannel intracochlear implant insertion depth. , 1993, The American journal of otology.

[27]  Stephen J. Rebscher,et al.  Considerations for design of future cochlear implant electrode arrays: electrode array stiffness, size, and depth of insertion. , 2008, Journal of rehabilitation research and development.

[28]  R. Hilsinger,et al.  Computer-Generated Three-Dimensional Reconstruction of the Cochlea , 1989, Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery.

[29]  Margaret W Skinner,et al.  Role of Electrode Placement as a Contributor to Variability in Cochlear Implant Outcomes , 2008, Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology.

[30]  D. D. Greenwood,et al.  Critical bandwidth and consonance in relation to cochlear frequency-position coordinates , 1991, Hearing Research.

[31]  Marco Pelizzone,et al.  Acoustic to Electric Pitch Comparisons in Cochlear Implant Subjects with Residual Hearing , 2006, Journal of the Association for Research in Otolaryngology.

[32]  Thomas Klenzner,et al.  Quality Control After Insertion of the Nucleus Contour and Contour Advance Electrode in Adults , 2007, Ear and hearing.

[33]  Luboš Voldřich,et al.  Correlative study of sensory cell density and cochlear length in humans , 1987, Hearing Research.

[34]  S. Connor,et al.  CT and MR Imaging Cochlear Distance Measurements May Predict Cochlear Implant Length Required for a 360° Insertion , 2009, American Journal of Neuroradiology.

[35]  Graeme M. Clark,et al.  Computer-Aided Three-Dimensional Reconstruction in Human Cochlear Maps: Measurement of the Lengths of Organ of Corti, Outer Wall, Inner Wall, and Rosenthal's Canal , 1996, The Annals of otology, rhinology, and laryngology.

[36]  J. Geleijns,et al.  Evaluation of 4 Multisection CT Systems in Postoperative Imaging of a Cochlear Implant: A Human Cadaver and Phantom Study , 2008, American Journal of Neuroradiology.