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Updated: Jul 30, 2025
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Enhancing Electrode Location Assessment in Cochlear Implantation via Computed Tomography Image Fusion
Published on: January 17, 2025
493
Spread of the intracochlear electrical field: Implications for assessing electrode array location in cochlear
Samuel Söderqvist1, Ville Sivonen1, Juha Koivisto2
1Department of Otorhinolaryngology - Head and Neck Surgery and Tauno Palva Laboratory, Head and Neck Center, Helsinki University Hospital and University of Helsinki, Kasarmikatu 11-13, Helsinki 00130, Finland.
Hearing Research
|May 17, 2023
Summary
Electrical field (EF) measurements using monopolar transimpedance matrix (TIMmp) and bipolar transimpedance (TIMbp) can assess cochlear implant electrode position. These methods may reduce the need for imaging, improving patient care.
Area of Science:
- Otoacoustic Emissions
- Biomedical Engineering
- Neurosurgery
Background:
- Electrical field (EF) spread in the cochlea is influenced by tissue conductivity.
- Monopolar transimpedance matrix (TIMmp) measures widespread EF, useful for electrode alignment.
- Bipolar TIM (TIMbp) estimates local potential differences for subtle location assessments.
Purpose of the Study:
- Investigate the impact of scala area (SA) and electrode-medial-wall distance (EMWD) on TIMmp and TIMbp.
- Evaluate the potential of TIMmp and TIMbp to estimate SA and EMWD.
- Assess intracochlear electrode array positioning using electrical field measurements.
Main Methods:
- Temporal bone study using three electrode arrays (Slim Straight, Contour Advance, Slim Modiolar).
- Simultaneous TIMmp and TIMbp measurements with cone-beam computed tomography.
- Multiple linear regression analysis to correlate measurements with anatomical dimensions.
Main Results:
- Intracochlear EF peak negatively correlated with SA (r = -0.55, p < 0.001).
- EF decay was faster near the medial wall (r = 0.35, p < 0.001).
- TIMmp and TIMbp together estimated SA (R² = 0.47) and EMWD (R² = 0.44).
Conclusions:
- TIMmp and TIMbp measurements correlate with SA and EMWD.
- These electrical field measurements can assess electrode array position within the cochlea.
- Potential to reduce reliance on intra- and postoperative imaging for cochlear implant placement.
