Safetyness

Hi,
I need to protect operating personel from current shock. The problem is that a machine must be under high voltage in the time when somebody manipulates it. Now I consider the way to switch the power off when someone is to close to dangerous parts of the machine. I thought about some light curtains or scaners... but maybe there are some better ways to do this. The protected area schould be in 3D(The machine has irregular shapes), it should be relatively flexible and not very expensive.

Think of danger and not price.
Is this high voltage something to takes seriously (probably is) or it's current limited and in worst case will only give you
a shock but not really harm you?
If it can be dangerous, go with proper safety circuit. I would consider laser scanner(s) because you create custom irregular protective field.