Insertion trauma of a cochlear implant electrode array with Nitinol inlay

Area of Science:

• Biomedical Engineering
• Neurosurgery
• Materials Science

Background:

• Cochlear implant electrode insertion aims for perimodiolar positioning.
• Shape memory actuators offer potential for controlled electrode positioning.
• Hearing preservation electrode arrays require atraumatic insertion techniques.

Purpose of the Study:

• To evaluate the impact of integrating a Nitinol wire inlay into a hearing preservation electrode array.
• To assess the risk of insertion trauma associated with the modified electrode design.
• To determine if the shape memory effect influences electrode insertion behavior.

Main Methods:

• Six conventional Hybrid-L electrode arrays were modified with a 100 µm Nitinol wire inlay.
• Electrodes were inserted into human temporal bone specimens using a standard surgical approach.
• Histological analysis of embedded electrodes was performed to evaluate insertion trauma.

Main Results:

• Electrode insertion with the Nitinol inlay was straightforward, with no observed difficulties.
• Histological examination revealed no detectable insertion trauma.
• The shape memory wire effectively curled the electrode array post-insertion.

Conclusions:

• The integration of a Nitinol shape memory wire inlay is feasible in hearing preservation electrode arrays.
• This modification does not appear to increase the risk of insertion trauma.
• Atraumatic insertion of modified cochlear implant electrodes is achievable.