It is essential to detect cancer as early as possible for a good prognosis. Some lesions are only visible on MRI and not with ultrasound, mammography (x-ray) or CT. A biopsy is needed to take sample tissue for examination. A confirmed malignant tumor subsequently needs to be treated and some approaches also use a needle to remove or destroy the tumor (by e.g., electroporation, cryoablation or medicine injection). However, it is difficult to insert a needle manually to the right location. Could a robot do better?
Due to the strong magnetic field of an MRI scanner, we cannot use electromagnetic motors to actuate robots in the MRI. At RaM we use 3-D printed pneumatic stepper motors instead. Sunram is a series of robots for breast biopsy which has been under development since 2014 (video). Mamri is a generic instrument positioning robot arm with six degrees of freedom and relatively large workspace, of which development started in 2024 (video).
The Sunram and Mamri robots actually turn out to be quite fun to work and play with. Several MSc/BSc assignments are possible within the context of Sunram and Mamri robot arms. So far, around twenty students conducted such a project. Keywords are:
- Robot control (steer needle towards tumor)
- Automatic calibration (fiber optics?)
- Motion compensation (breathing and needle-tissue interaction; compensate use real-time MRI imaging via Access-I interface or other means)
- Human-machine interfacing (develop intuitive user interface, 6 DOF joystick? also for demo's), see video
- Develop new stepper motors (focus on mechanical engineering), see video
- Develop new robot using existing stepper motors (prostate biopsy robot? Sunram 8?)
- Write out full clinical workflow (which organs are most relevant? which system parts are disposable, sterilizable?), for Health Science students
- End-effector design (does it align the needle guide only, or also insert the needle itself and fire the biopsy gun?)
- Force sensing (based on fiber optics or pneumatics?)
- Digital twin (virtual / mixed reality, using Hololens 2 or other device), see video
- Phantom fabrication (sometimes part of a broader assignment)
Depending on your background (study programme and courses) and personal interests we can see if we can draft a specific assignment around any of these topics.
Contact me at v.groenhuis@utwente.nl and I will gladly show what keeps us busy in the lab.