A modular micro-macro robot system for instrument guiding in middle ear surgery

Surgical interventions at the middle ear are very challenging tasks for surgeons. At an otosclerosis the stapes is immobile because of an abnormal bone growth so that the sound transmission is disturbed. Therefore, a stapedotomy is performed where the stapes is partly replaced by a small implant to reconstruct the path of sound transmission. The state of the art is to use handheld micro instruments. However, the structures are, as well as the required precision, in the range of sub-millimeters, and the view is limited due to the narrow ear canal. Because of the human hand tremor, which goes from some tenth millimeters up to some millimeters, the intervention is very delicate. Until now, there are no assistance systems for guiding surgical instruments available. In this contribution we present the further development of a formerly presented micro-macro telemanipulator system. New functionality for coarse and fine positioning was implemented, as well as a processing unit and a quick-changer for exchanging the micro manipulator. In a preliminary experiment standard-based position repeatability is obtained. It is shown that the repeatability of the current macro robot is appropriate for the task and so the approach has high potential for supporting the surgeon in ENT surgery.