[Clinical use of a micromanipulator system: preliminary clinical experience in middle ear surgery]

Nowadays all procedures in tympanoplasty are performed using conventional instrumentation without any mechatronic based manipulators. A micromanipulator system (MMS) holds microinstruments and transmits the surgeon's hand movements to a monitor, thus, improving precision and ergonomics.

Using the Cartesian principle, a telemanipulator with three linear degrees of freedom controlled with a joystick was designed. The three axes are powered by a servomotor. The manipulator is equipped with a sterilizable instrument holder, which is placed on a sterile covered system. On this instrument holder, sterile surgical instruments can be clipped and can be easily changed during surgery. In the scope of this study, the MMS was used to perform a tympanoplasty III in 20 patients. A workflow expert protocol, a video of the surgery, and a questionnaire completed by all surgeons were evaluated.

Clinical use of the MMS 2.0 was performed in all 20 patients as planned. A partial/total ossicular replacement prosthesis (PORP/TORP) was used in all cases with the MMS as planned. Significantly more time was necessary not only to prepare for surgery but also to prepare the equipment intraoperatively, and the incision to suture time was longer. The number of intraoperative changes of instruments decreased by 24%. The frequency of contact between the instrument and the prosthesis was significantly decreased. All questionnaires indicated that further improvement of the MMS is needed.

The manipulator MMS 2.0 was successfully used in the clinical setting for the first time. The tool offers great potential for middle ear surgery (e.g., tympanoplasty III, stapes surgery and cochlear implant insertion). The principal of telemanipulation (master-slave) could be transferred to middle ear surgery. However, numerous technical improvements are still required.