Considerations for the design of future cochlear implant electrode arrays: Electrode array stiffness size and depth of insertion

摘要

The level of hearing rehabilitation enjoyed by cochlear implant recipients has increased dramatically since the introduction of these devices. This improvement is the result of continual development of these systems and the inclusion of subjects with less severe auditory pathology. These developments include advanced signal processing, higher stimulation rates, greater numbers of channels, and the development of more efficient electrode arrays that are less likely to produce insertion damage. New directions in the application of cochlear implants, particularly in combined acoustic and electrical stimulation, and increasing performance expectations will place greater demands on future electrode arrays. Specifically, the next generation of arrays must be reliably inserted without damage, maintain residual acoustic function, and may need to be inserted more deeply.In this study we measured the mechanical properties of 8 clinical and prototype human cochlear implant electrode arrays and evaluated insertion trauma and insertion depth in 79 implanted cadaver temporal bones. We found that the size and shape of the array directly affects the incidence of observed trauma. Further, arrays with greater stiffness in the plane perpendicular to the plane of the cochlear spiral are less likely to cause severe trauma than arrays with similar vertical and horizontal stiffness.