Article
Impedance-based CI Electrode Array Insertion Depth Estimation (en)
* Presenting author
Abstract:
Safe and effective cochlear implantation requires postoperative confirmation of correct electrode placement. More specifically, the knowledge of electrode insertion depths can be used for patient-specific programming of audio processors, such as bilateral matching or tonotopy-based fitting. We demonstrate how readily available and routinely performed postoperative impedance telemetry can be used to determine electrode insertion depths without the need for radiation-imposing imaging. The role of impedance subcomponents is discussed, and different approaches to estimating insertion depth are presented. A dataset of more than 150 preoperative and postoperative computed tomography scans and corresponding impedance telemetry was compiled as ground truth. Statistical models based on Bayesian ridge regression achieve submillimeter accuracy (mean absolute error 0.6 mm; SD 0.5 mm) and enable the detection of extracochlear electrodes or cases of array migration. Our technique is particularly important for the follow-up of pediatric cochlear implantation cases to avoid radiation dose and for clinical centers that do not have the resources for radiological follow-up.