Help: appealing 10yr ILR refused on absences

[lefty74]

Dear all
I have searched through the boards for information relevant to our situation but have not found what I'm looking for.
My wife applied for ILR based on ten year residence but was refused because she spend 686 days out of the country over the last ten years (limit is 540).
The case worker told us we might be able to appeal when we mentioned some of the trips back to the USA (her home country) were for medical reasons (compelling compassionate grounds). We didn't mention this in the application because we didn't realise we were over. We have not compiled evidence of the medical treatment for chronic illness. There were 42 days of actual medical visits plus time convalescing. There were two specific instances where a doctor told her to delay travelling home. There was also a 12 day trip for a funeral.
Here's where we are stuck. We were given an appeal form IAFT-5 and are not sure what grounds our appeal comes under.

Is this a human rights appeal?
If so, which article would it come under? I read that Article 8 (private life) had been used, but it seems that since the decision I read about (2012) they have changed the immigration rules so that it will only apply if you've been in the country 20 years.
If not, I guess we must write in box 7 of the form, "Deprivation of Citizenship" because it says to use that if you are unsure which box to complete.

How much evidence should we submit?
Is it necessary to submit a discharge letter or equivalent for every single medical visit, or will a list of dates plus a letter from two doctors describing the long term illness suffice?

[cyborg001]

Can appeals like this sometimes win given they refused correctly under the rules?