Sharps containers are definitely eligible. I don't see a clear statement about cases and protective gear, but when I got a CPAP machine it included a carrying case and I didn't subtract that when I got HSA reimbursement for the rest. I think your expenses are ok, based on your description that they are somewhat specialized (a locking backpack) and assuming you don't also use them for more than trivial personal purposes. (What I mean by more than trivial, is that it would be ok to put your wallet and phone in the medical backpack, that's a trivial personal use -- but if the medical backpack evolves into a carry-all for your life on the road and its medical use becomes less important, then it wouldn't qualify any more.)
