The machines that deliver MRI and radiotherapy are inherently and seriously hazardous. Combining both of them into a single unit has enormous value (being able to clearly see the tumour and any movement during radiation delivery for example), but it also creates many new challenges. For example, the users who deliver radiation therapy are not the same people as use MRI machines and so there is a significant new training problem. Also, the UI has to provide comprehensible and usable information about the state of the MRI as well as the state of the radiotherapy Linac. And all embedded in familiar, but different work processes.
As with all medical devices there is a need to demonstrate the safe usability of the new device, with users who are not familiar with all the development work and in a context which reflects real world use.
Designing, planning and executing those usability studies was no small feat and took a very large number of people.
