I’m brand new to oxygen. The DME my pulmonologist sent my Rx to us delivering my POC and home continuous flow unit Monday. All they’ll tell me is that it’s a pulse unit and a continuous flow unit. I really need a light weight unit because I have back problems. I hate not having any input in my equipment. Has anyone dealt with Inogen.com for their O2? Can I have the dr cancel the one Rx and go through Inogen