Development, control and interfacing of pneumatic MRI-guided robots

BSc assignment

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 a tissue sample for examination. A confirmed malignant tumour subsequently needs to be treated, and some approaches also use a needle to remove or destroy the tumour (e.g., electroporation, cryoablation or medicine injection). However, it isn't easy to insert a needle manually into 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 a relatively large workspace, for 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. Keywords suitable for BSc assignments:

  • Robot control (steer the needle towards the tumour)
  • Human-machine interfacing (develop an intuitive user interface, 6 DOF joystick/spacemouse/HandTool? also for demos), see video
  • Develop new stepper motors (focus on mechanical engineering), see video
  • Develop a new robot using existing stepper motors (prostate biopsy robot? Sunram 8?)
  • Write out a full clinical workflow (which organs are most relevant? which system parts are disposable, sterilizable?)
  • End-effector design (does it align the needle guide only, or also insert the needle itself and fire the biopsy gun?)
  • Force sensing
  • 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 you what keeps us busy in the lab.