I have a friend with an undiagnosed disease and am thinking about doing the same thing. One thing I've thought about is using a Bayesian Network as a tool, but then again, I'd have to be really careful about how I plug in data, and it would be good to know if there are other approaches to this as well. PM me if you find a good way to go about this.
That map is actually specific to the IRC channel IIRC, as the channel is kind of it's own spin-off community in many ways according to some of the channel old-timers.