I am almost at Stage 4 COPD, but believe it or not, still active despite gasping just walking to the mailbox. My wife and I would like to do some more traveling while I am still relatively healthy. I have a couple little Pari Neb Trekkers, but the batteries do not last for more than one maybe two treatments. Are there any recommendations for portable nebulizers? My doctor said that the mesh ones do not deliver the medication deep enough, that one should get a nebulizer with good compression to get that medicine deep in the lungs. Thanks in advance!