Hydraulic snake-like robot for Endoscopy

• Applicants: Professor Dr.-Ing. Thomas Seel, since 3/2023; Professor Dr.-Ing. Jan Stallkamp
• Subject Area: Automation, Mechatronics, Control Systems, Intelligent Technical Systems, Robotics ; Biomedical Systems Technology
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 433586601

Endoscopic procedures for diagnostics and therapy are changing medicine. Interventions can thus be minimally invasive and have not only become more efficient (i.e. cheaper and faster), but the convalescence time has also been minimized.Two important factors must be fulfilled for a successful intervention: Good manoeuvrability is required to reach areas that are difficult to access. In the target area, the procedure requires high structural rigidity in order to withstand manipulation forces and provide the physician with a fixed working platform. However, today's endoscopes cannot meet both requirements at the same time. Either purely rigid or purely flexible endoscopes are used; stiffenable mechanisms are extremely rare, even in research. New for endoscopy is the approach presented in the DFG project "Fully Actuated Electromagnetic Bending Actuator for Endoscopy", which allows a high quality of adaptation to curved paths through hyperredundancy and offers a particularly good basis for manipulation through electromagnetic actuation and the associated high holding torques. The electromagnetic actuation results in only two stable tilting positions. However, these limit the positionability of the system and make it difficult to use it in a medical environment. Based on this preliminary work, a hydraulically actuated snake-like endoscope will be investigated in this project. In the focus is a tilting actuator, which combines different advantages: The hydraulic pressurization of two bellows arranged antagonstically around a tilting axis allows the adjustment of different tilting angles, which significantly increases the positioning accuracy of the endoscope. With a suitable actuator design, a clever arrangement of the bellows and control of the valves, different system stiffnesses can also be achieved. A high number of actuators enables both temporal and spatial flexibility to be achieved, which is a basic prerequisite for anatomy-optimal adaptation with simultaneous provision of a rigid working platform for the physician. If a biocompatible fluid and a medically acceptable system pressure are selected, real use in the clinic is also promising.In this project, actuator design will be researched, computer-aided modeled and experimentally evaluated. In addition, an endoscope consisting of a large number of individual actuators requires a reliable hydraulic supply concept that can be easily miniaturised. The motion planning should in particular take into account the adaptation of stiffness, whereby kinematic as well as dynamic modelling of the overall system is necessary. All models and methods will be experimentally evaluated using a prototype.

• DFG Programme: Research Grants
• Ehemalige Antragstellerinnen / Ehemalige Antragsteller: Professor Dr.-Ing. Tobias Johannes Ortmaier, until 5/2021; Dr.-Ing. Svenja Spindeldreier, from 5/2021 until 3/2023