Android UI with no buttons?

Question

I am trying to create an android TABLET application for my grandma who is sufferring from Mild cognitive impairement. One of the features of the app is intelligent schedulers/reminders .For ex: The app would say "Did you take your red pill?" Yes or No. If its no or no reply , then a text message is send to my mobile .

Now her hands shiver and shake so eventhough the buttons are huge for Yes or No she tends to press the wrong one by mistake. IS there any alternative to create a UI such that she doesnt hve to depend on the button? Please help....

Answer 1

Though i have no knowledge about android, i have a work-around with the design idea:

Let there be only one big button: "Yes" If she hasn't taken the pill, then she should NOT press the button, but rather go and take the pill, and then press "yes". Until then, the app would repetitively ask the question every 30 seconds or so (may be with a sound alarm).