A force sensing Automated Insertion Tool for cochlear electrode implantation

Cochlear electrode insertion is a challenging manual procedure. One technique requires the physician to coordinate the motions of an electrode array approximately 1mm in diameter and the smaller stylet within it, using miniature forceps. A new minimally invasive access technique precludes forceps insertion because the electrode must travel through a small-diameter drilled hole to reach the cochlear access point. To address this, we present an automated insertion tool. This second generation device not only enables deployment in the minimally invasive setting, but also makes insertion velocity profiles repeatable and can sense insertion forces. Force sensing is essential because insertion forces can indicate impending damage to cochlear membranes, but are below the thresholds that can be sensed by human hands. The Automated Insertion Tool we present is designed to be compact and lightweight for straightforward integration into the operating room environment. It is able to insert an electrode with a resolution of less than 1µm, achieve velocities of up to 5mm/sec and resolve forces as small as 0.005 N.