Sunram 5 is a MR safe robotic system for breast biopsy. It is driven by novel pneumatic stepper motors which are rapid prototyped by 3-D printing and laser-cutting. Being entirely made of plastic materials, the robotic manipulator does not interfere with the strong magnetic field of the MRI scanner in any way and is therefore MR safe. The system demonstrates several innovative concepts such as dual-speed motors, a serial kinematic configuration with the rigidity of parallel linkages and a pneumatic biopsy gun with safety needle ejection mechanism. It can be positioned and locked at arbitrary positions and orientations around the breast thanks to the versatile fixation system, making it possible to access challenging lesions. Fiducials in the frame allow to define a coordinate system in which the robot is able to navigate to a given target lesion and perform the biopsy.
Like its predecessors (Stormram 1-4), Sunram 5 is a proof-of-concept for research purposes demonstrating significant potential in further developments towards actual usage in hospitals. The patented stepper motor technology enables development of a broad range of linear, curved and rotational stepper motors with many possibilities towards miniaturization, high energy transfer and precise control, easily adapting to different applications inside and outside the MRI scanner. The researchers involved from RaM are Vincent Groenhuis MSc, Marcel K. Welleweerd MSc, dr. Françoise J. Siepel and prof. Stefano Stramigioli, supported by dr. Jeroen Veltman from ZGT and Abe van der Werf from Machnet B.V.