The t-pocket secures the R/S with anatomically consistent strong points of fixation while precluding dural complications. There were no cases of migration or intracranial complication noted. Further trials and device-specific training with this technique are necessary before it is widely adopted.

The temporal bone studies showed the Contour electrode array to be generally positioned closer to the modiolus than the standard Nucleus straight array, and to have an equivalent probability of causing insertion-induced damage.

Objective: This study was conducted to evaluate the insertion properties and intracochlear trajectories of three perimodiolar electrode array designs and to compare these designs with the standard CochlearlMelbourne array. Background: Advantages to be expected of a perimodiolar electrode array inclu<;le both a reduction in stimulus thresholds and an increase in dynamic range, resulting in a more localized stimulation pattern of the spiral ganglion cells, reduced power consumption, and, therefore, longer speech processor battery life. Methods: The test arrays were implanted into human temporal bones. Image analysis was performed on a radiograph taken after the insertion. The cochleas were then histologically processed with the electrode array in situ, and the resulting sections were subsequently assessed for position of the electrode array as well as insertion-related intracochlear damage. Intracochlear multichannel cochlear implants have successfully provided auditory information for profoundly deaf patients by electrically stimulating discrete populations of auditory nerve fibers via a scala tympani electrode array. The straight, yet flexible, tapered Melbourne/Cochlear electrode array can be safely implanted into the human cochlea. However, histologic and radiologic examination of implanted temporal bones showed that the electrode array is usually positioned along the outer wall of the scala tympani (1-5). The array is, therefore, some distance from the spiral ganglion cells in the Rosenthal canal and their peripheral processes. However,

Objectives This pilot study details the use of a software tool that uses continuous impedance measurement during electrode insertion, with the eventual potential to assess and optimize electrode position and reduce insertional trauma. Study Design Software development and experimental study with human cadaveric cochleae and two live surgeries. Methods A prototype program to measure intracochlear electrode impedance and display it graphically in real time has been developed. The software was evaluated in human cadaveric temporal bones while simultaneously making real time fluoroscopic recordings, and in two live surgeries during intracochlear electrode insertion. Results Impedance changes were observed with various scalar positions, and values were consistent with those obtained using clinically available software. Using Contour Advance™ electrodes, impedance values increased after stylet removal, particularly when using the monopolar mode. Conclusion Impedance values seem systematically affected by electrode position, with higher values being associated with proximity to the cochlear wall. The new software is capable of acquiring impedance measurements during electrode insertion and this data may be useful to guide surgeons to achieve optimal and atraumatic electrode insertion, to guide robotic electrode insertion, and to provide insights about electrode position in the cochlea.