Robotic Arm Assisted Slow Electrode Insertion and Simultaneous Measurement of Cochlear Microphonics in Cochlear Implantation.

Cochlear microphonic potentials (CMPs) are an electrical response predominantly of the outer and, to a smaller degree, the inner hair cells to acoustic signals. They can be used to monitor hearing and structure preservation during cochlear implantation. Among other precautions, slow and steady electrode insertion has proven beneficial in this regard. In this article, the authors present a combination of robotic-assisted implantation and observation of CMPs. CMPs are recorded through the cochlear implant tip electrode before and after opening the round window membrane, during insertion, and in the final electrode position. Acoustic pure tones at frequencies determined by the patient's hearing status are used as stimuli. To set the electrode insertion trajectory, a 5-degree-of-freedom manipulator (2 rotational, 3 translational) is used. Electrode insertion is performed with a linear actuator controlled by the surgeon. Additionally, the electrode entrance can be manually guided, and the trajectory readjusted accordingly based on CMP observations. Experiences so far indicate that human-guided robotic CI electrode insertion, combined with simultaneous CMP measurement, is feasible and appears to be a promising strategy to improve cochlear structure preservation.