See a decent wills/probate/estates advisor to get a wil drawn up to try and prevent this, i know some people transfer the property or part of it to children in order that it cannot be claimed in this way.
Just make sure it is all drawn up properly and that there are no issues with your children (if any) and that your occupation is protected for as long as you need it.
My father in law has looked into this and it isn't easy.
As Jenna says, you need a specialist to sort it for you, which can be expensive.
My FiL was told that in some cases, if the authorities believe you have taken measures solely to avoid having your assets taken, they can have them all undone. So he didn't bother!
Some authorities will ask for a list of any gifts of money or property made by you to your family within a set period of time, which can be as much as 10 years. If such is the case they can then ask your children to pay for your care. However they usually do not make a move on property if one of you is still living in the marital home.