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TY - THES AU - Niesche, Annegret TI - Handgehaltener Miniaturroboter für die orthopädische Chirurgie VL - 76 PB - RWTH Aachen University VL - Dissertation CY - Düren M1 - RWTH-2024-07914 T2 - Aachener Beiträge zur Medizintechnik SP - 1 Online-Ressource : Illustrationen PY - 2024 N1 - Druckausgabe: 2024. - Auch veröffentlicht auf dem Publikationsserver der RWTH Aachen University N1 - Dissertation, RWTH Aachen University, 2024 AB - Numerous assistance systems have been developed to support the surgeon in effective and efficient bone machining with minimally invasive access. One possibility of interaction is the principle of synergistic control. It enables the robotic assistance system to control and optimize individual target variables while actively involving the operator into the process. However, current approaches show disadvantages with regard to flexible integration into the surgical work environment and workflow, require invasive bone fixation or offer only limited possibilities for process optimization. This thesis investigates the approach of using a synergistic hand-held active robot for bone machining. After manual coarse positioning, the robot executes the fine movement of the instrument for bone machining, thereby compensating for undesired human movements. By manually repositioning the robot, the accessible working space is expanded. The system itself therefore can be designed with a smaller working space and occupies less space in the operating room compared to robots which are installed at a fixed position in the room. A successful demonstration of this approach on a hard material like cortical bone is not known so far. In order to enable the compensation for the human reaction movements caused by the process forces as well as involuntary tremor and drift movements, the investigated approach was extended using a mechanical support of the robot for stabilization. The proposed approach has been investigated for milling the implant seat in minimally invasive unicondylar knee arthroplasty (UKA), i.e. for the fabrication of a three-dimensional free-form surface on the bone. A functional prototype of the robot, held by the operator with both hands and with a weight of 2.5 kg, was realized. In addition, repositioning strategies for use with a mechanical support unit were presented. In milling tests on bone substitute material, a deviation ranging from 0.32 mm to 0.99 mm (RMSE) of a machined surface from the planned surface was achieved. This is within the deviation of 0.67 mm (RMSE, σ = 0.37 mm) achieved with the commercial, visually guided NAVIO system for UKA surgery, which does not allow for automated and thus systematic control of the bone machining parameters (e.g. milling tool path, depth, feed rate). In addition, the applicability of the hand-held robot was demonstrated in a UKA surgery on a human cadaver. A deviation between -0.7 mm and 0.6 mm of the machined bone surface from the planned surface was achieved with a bone machining time of 5 minutes for the tibial and 10 minutes for the femoral condyle. Again, values comparable to the NAVIO system were achieved. To sum up, milling bone using a hand-held, active robot with a mechanical support is possible with the accuracy and efficiency of a commercial system for UKA, but with the advantage of an automated and thus systematic implementation of optimal milling parameters. LB - PUB:(DE-HGF)11 ; PUB:(DE-HGF)3 DO - DOI:10.18154/RWTH-2024-07914 UR - https://publications.rwth-aachen.de/record/991823 ER -