One sure way to avoid mistakes is to have a simulation before doctors perform surgeries. Brain Surgeons in Halifax, Canada can now do dry runs of their patients' brains using models of them. The simulator uses MRI images that allow them to get digital copies of their brains.

First, patient data from functional magnetic resonance imaging (fMRI) is rendered into a 3-D, high-resolution model of an individual's brain. After the model is loaded into the system, doctors can touch and manipulate tumors and other virtual objects on screens in real time using a physical instrument resembling a scalpel. The instrument has six degrees of freedom and re-creates the force-feedback of the real tool and the varying resistance of tissue in brain regions with differing toughness. Meanwhile, photo-realistic on-screen imagery shows the simulated surgery, including bleeding and pulsing gray matter.

Will it also have error detection and a time based counter that tells you how long more you have to perform the surgery?  [Technology Review via PopSci]