Situation
Robots can be used to assist doctors or medical specialists in performing a biopsy guided by Magnetic Resonance Imaging (MRI). MRI is used to visualize lesions (abnormal tissue) as this gives more contrast between soft tissues, as compared to echography or CT. It is common to perform a biopsy to diagnose a patient for breast or prostate cancer, which are some of the most common cancer types worldwide.
A limitation is put on MRI safe robots as the environment in and around the MRI machine has a large magnetic field. This prevents the use of certain material, such as iron or steel, from being used in the robot, as these can interfere with the MRI machine.
In the RAM group of the University of Twente, V. Groenhuis has developed MRI safe robots. These robots can be actuated using 3D printed pneumatic stepper motors and controlled by the MAMRI controller, which controls the flow of pressurized air using electronic values and a microcontroller. The user interface (UI) of this device was developed for general lab use, with reprogrammable buttons, switches, knobs, and a screen. However, this flexibility comes at the cost of usability, which is an important aspect to consider for the use of robots in the lab and possible future use in a clinical setting.
Challenge
Because of these usability issues, a more usable UI is to be designed that helps users to more easily control the MAMRI robots. For this, several input modalities can be considered, but must be available, give enough user feedback, and can process inputs for robots with more than 3 degrees of freedom (DOF).
User testing will be used to determine the effectiveness and usability of the user interface. If multiple user interfaces can be developed, these can be compared with each other.
To increase the easy use of the UI, its software should be modular, and properly integrated with the MAMRI controller code, where future designers can easily swap out parts of the control code. Not only should the software be integrated, also different hardware configurations of the control panel and different configurations of robots should be integrated. Where robots with and without positional feedback are supported, to give the most feedback to the user.
Questions
How to design an interface that improves the usability of the MAMRI controller, and that is intuitive for users that have not used the MAMRI controller before?
What input modality can provide the needed precision, control over three or more 3 DOF, and improve the usability of the interface?
How can meaningful and effective user feedback be given when a MAMRI robot is controlled?
How can the interface be integrated with the existing robots and the MAMRI controller?
Practical Aspects
A constraining factor is that the UI must be integrated into the existing MAMRI controller. The interface should not rely on devices that are hard to set up, or limited in their availability, as this would increase the effort to set up the controller and reduce the overall usability.
The limited computing power on the microcontroller affects what kinds of visualization and control can be done. However, a web interface allows for computing on the client device, like a tablet or phone.
Another important aspect is the precision that can be achieved, large and small positional changes should be able to be performed using the interface.
The interface should be able to integrate with different robot arms, with different configurations. But allow for use with or without positional feedback.
Lastly there is the problem of controlling more than 3 DOF, Solutions to this problem either requires mode switching or makes use of more complex user inputs, like 3D mouses.