Hi,
I'm not aware of one, such all-encompassing figure.
I doubt that you will find one - "medical devices" is a very broad and diverse field. Almost everything related to medical devices design is risk-based today, so it comes down to what the device is, what it is intended to do and what it can (unintentionally) do, and what the risk is.
Sorry, and I'll be happy if someone will prove me wrong...
Ronen.