University of Twente Student Theses
Sensorization and Control of a Multi-Segment Tendon Continuum Robot for Endoscopic Procedures
Horck, ir. Iven van (2025) Sensorization and Control of a Multi-Segment Tendon Continuum Robot for Endoscopic Procedures.
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| Abstract: | Endoscopy is a common medical procedure, performed millions of times per year worldwide, to diagnose and treat gastro-intestinal and respiratory diseases. These procedures are, however, not without risk. There is a chance that improper control of the endoscope by the endoscopist, caused by a lack of information about the robot's surroundings, can cause the endoscope to perforate the walls of an organ, which is life-threatening. This thesis presents an 8 DOF tendon continuum robot, that is capable of avoiding the walls of the organ its passing through. It has 24 optical reflective sensors on the robot's sides, pointed outwards in four sets of six. These sense the robot's surroundings up to a distance of 3.5 cm, with a field of view of 40.8 degrees per sensor. Two control methods evaluated: 1) A PID controller that controlled the 8 DOF as 4 sets of 2 DOF. 2) A model-based (MB) controller that uses the constant curvature model to control all 8 DOF. In simulations, the MB controller had a 92.6% p=0.000 loss reduction compared to the PID controller when positioning the robot in a desired location. Physical robot experiments were performed whereby an obstacle was moved towards the robot to measure the robot's deflection. If this obstacle was visible only to the fourth segment from the base, then the the MB controller was able to avoid the obstacle for a 92.9% p=1.0*10^-10 longer distance than the PID controller. If the obstacle was visible to both the fourth and third segment, the MB controller outperformed the PID controller by 65.5% p=1.8*10^-5. If the obstacle was visible only to the third segment, the MB controller is outperformed by the PID controller by 23.5% p=1.9*10^-6. Overall, the robot and the MB controller demonstrated effective obstacle avoidance and adaptability within constrained environments. Further research should focus on reducing the robot size, to more closely align its design with endoscopes. |
| Item Type: | Essay (Master) |
| Faculty: | TNW: Science and Technology |
| Subject: | 44 medicine, 52 mechanical engineering |
| Programme: | Biomedical Engineering MSc (66226) |
| Link to this item: | https://purl.utwente.nl/essays/106220 |
| Export this item as: | BibTeX EndNote HTML Citation Reference Manager |
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