A cochlear implantation robot in surgical practice

Cochlear implantation has become the standard treatment for severe to profoundly deaf patients over the last 20 years and is likely to increase as instrumentation systems improve such that patients with less deficiency can benefit and if the procedure can lead to accurate and a more efficient process of implantation. The critical step in the operation appears to be creating the cochleostomy, through which the implant electrode can be passed. A cochleostomy is created by drilling away the bony outer cochlea wall and, ideally, leaving the underlying endosteal membrane intact. The membrane is opened with a knife and implant is inserted. Inadvertent protrusion of the drill through the endosteal membrane may damage the scala tympani or osseous spiral lamina, and will contaminate the endolymph and perilymph with bone dust which, combined with the pressure surge experienced, may lead to a reduction in residual hearing. If the endosteal membrane is not perforated during the drilling process, and is opened by a knife, the damage to the cochlea will be minimised and residual hearing will be preserved. It has been shown that robotics can be applied in microsurgical tasks as a tool by automatically controlling the interaction between tissue and the tool point. The research reported here has led to clinical trials of an autonomous surgical robot system able to carry out the critical process of penetrating the bone tissue of the wall of the cochlea without penetration of the endosteal membrane located immediately inside the cochlea. Use of the robotic micro-drill in theatre represents the first application of an autonomous surgical robotic device and has shown that this is the ideal way to prepare a cochleostomy. The consistent results and the smooth form of the cochleostomy will enable more consistent insertion of implant electrodes and the likelihood of consistent results in terms of electrode performance. The means to avoid penetration of the endosteal membrane is expected to - - lead to a reduced complication rate.