Medical expense deduction- I need to buy a new bed this year (2017) due to a major back surgery to alleviate chronic pain. Can I deduct the cost of the bed?

Do I have to purchase the bed from a medical supply store or can it be from a regular bed store? H and R block told me it must be bought from a med supply store but I have not seen that written anywhere online or in the tax code. Bed has electric base with adjustable lumbar support and head and leg rest moves up and down to help alleviate pressure points and my chronic pain. I live in Illinois.