Vol. 105 (2026): Vogt, Ivan: MRT-kompatible und robotische Assistenzsysteme für bildgestützte und minimal-invasive Eingriffe
The future of interventional medicine is characterized by the continuous reduction of surgical invasiveness. Despite ongoing improvements through imaging modalities such as magnetic resonance imaging (MRI), computed tomography, and sonography, the clinical implementation of robotic assistance systems remains limited by regulatory, economic, and technical constraints. This study presents the development and evaluation of a robotic assistance system (µRIGS) and an abdominal motion phantom (MURPHY) focusing on MRI-guided interventions. µRIGS was optimized to enable autonomous interventions and haptic feedback during remote needle insertion. MURPHY serves as a realistic testing platform considering physiological organ movements. The µRIGS instrument positioning unit was enhanced using technical ceramics and driven by 4m long Bowden cables. The vacuum-based robotic patient interface (diameter 13,5cm, 106g) enables flexible fixation of the instrument positioning unit across various body regions with holding forces of 10−66N. An integrated metamaterial MRI coil amplifies the signal by up to 200% at a tissue depth of 2cm. The sensorless force measurement utilizes mechanical resistance during needle insertion for collision detection and haptic feedback. With a sampling rate of 800Hz and a force resolution of 0.26 ± 0,22N, a user study demonstrated realistic haptic perception. The automated instrument positioning, based on MRI-guided marker detection, achieved a puncture accuracy of 1.31 ± 0,68mm with a puncture duration of 2.3 ± 0,91min. MURPHY employs modified polyvinyl alcohol cryogels to replicate various tissue types, reproducing their relaxation times, dielectric properties, and elasticity. Long-term tests revealed elasticity reduction due to fluid loss. A semi-flexible chest and an MRI-compatible motion unit enable realistic simulation of respiratory-triggered organ movements. The developed systems demonstrate improvements over the current state of technology. Further studies are necessary to validate technological advancements for broad clinical implementation. Key aspects include enhancing robotic functionality in moved body regions, optimizing haptic perception, and expanding multimodal application possibilities. The goal is to overcome regulatory and economic barriers and develop telerobotic surgical techniques for underserved regions.
ISBN: 978-3-948749-61-3
