One of the biggest challenges facing surgeons carrying out the removal of a brain tumor is working out how much of it they can remove without damaging the patient's life afterward.
A wrong decision can leave people unable to speak, move or think clearly.
Now, scientists at the University of Cambridge are working with surgeons to build a new device for the operating theater and BBC Inside Out witnesses live research testing.
Ben Rush, 29, had a seizure in bed which lead to the discovery of a large tumor at the front of his brain. Incredibly, it could have been growing for a decade without him knowing.
Within weeks, Ben was in the operating theater at Addenbrooke's hospital in Cambridge along with BBC Inside Out and a neuroscientist from Cambridge University.
The operation for removing a brain tumor currently requires the patient to be awake for doctors to know what parts of the brain manage different functions.
During Ben’s operation, neuroscientist Yaara Erez uses techniques which require Ben to use multitasking skills while they use electrodes to listen to his brain.
The research is part of the creation of a much more detailed map of brain functions for a new device that will eventually – within ten years - help surgeons tailor decisions according to the patient’s needs.
If they do physical work, the surgeon could preserve more physical functions. Others might want to save parts of their brain that help them manage big projects.
Following the operation, Ben is aware the tumor could return but is optimistic:
I think you only get one life so you have to make the most of what you have don’t you and if you sit around worrying about something like this, you are only taking away from the joy you could potentially be having.”
Watch Inside Out on Monday 15th at 7:30 pm on BBC1 East. It’ll also be available on the BBC iPlayer.