[Clinical use of a micromanipulator system: preliminary clinical experience in middle ear surgery]. / Klinischer Einsatz eines Mikromanipulators : Erste Erfahrungen in der Mittelohr- und Felsenbeinchirurgie.

PROBLEM DESCRIPTION: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

[Influence of an auto-motorised optical navigation camera to the surgical workflow in ENT surgery]. / Die Auswirkungen einer robotergeführten Navigationskamera in der HNO-Chirurgie.

BACKGROUND: With the application of optical navigation systems an interruption of the line of sight (LOS) between navigation camera and the patient/instrument can occur. The goal of this work is the clinical evaluation of a newly developed system for automatic adjusting of an optical navigation camera (Navigation Camera Assistant, NCA). NCA is a miniature robot, which is able to position the navigation camera autonomously in 2 levels. MATERIAL AND METHODS: The influence of the NCA was examined on 128 patients: 55 procedures at the paranasal sinuses and 9 procedures at the temporal bone with the NCA were evaluated and compared with available workflow data of adequate surgeries without NCA. An optical navigation system of the 3 (rd) generation was used. The following parameters were recorded: Preparation time of the system, time of using the system, LOS-interruptions. RESULTS: The LOS-interruption decreased in the group of FESS with application of the NCA by 92%, in the group tympanic cavity by 85%. The number of corrective motions of the navigation camera was increased with application of the NCA in the group FESS by 73%, in the group tympanic cavity by 89%. The usage time of navigation increased with the application of the NCA in the group of FESS by 36%, in the group tympanic cavity by 16%. CONCLUSIONS: With a motorized navigation camera can be the interruption rate of LOS significantly improved at frontal and lateral skull base. The technical expenditure for installation of the NCA robot is little even during, for this reason there is the potential that this module can be established for the clinical practice.

[Sensitivity of neurochemical dementia diagnostics in CSF compared to 99mTc-SPECT in Alzheimer's dementia]. / Vergleichende Sensitivität der neurochemischen Demenzdiagnostik im Liquor und rCBF im 99mTc-SPECT bei Patienten mit Alzheimerdemenz.

The diagnosis of Alzheimer's dementia is currently changing from a late and exclusion diagnosis towards a pathophysiology-based early and positive diagnosis. Especially advances in neuro-chemical dementia diagnostics in the cerebrospinal fluid (NDD-CSF) and imaging techniques like PET, SPECT or MRI are of particular interest. Unfortunately, many studies investigated only either one or other technique. In the present study 56 patients (average 67.1 years; average mini-mental status test (MMST) 22.2) were examined with the clinical diagnosis of Alzheimer's dementia. All patients both underwent NDD-CSF as well as 99mTc-SPECT. Only the SPECT, but not the NDD-CSF correlated with disease severity. Sensitivity of NDD-CSF was 89 % and SPECT 48 % for all patients and 93 % resp. 61 % for patients with MMST < 24. Below MMST 20 both methods had equal sensitivity. Both diagnostic techniques showed no statistic coherence (p = 0.27), neither after correction for subgroups like disease severity or the APOE genotype. Our results are compatible with the hypothesis that the NDD-CSF reflects beta-amyloid-aggregation and Tau-Protein pathology as a pathophysiologic biomarker. Our results suggest that SPECT is rather a state parameter for the rCBF changes following cortical neurodegeneration.