Piper Jaffray analyst JP McKim views the recent pullback in shares of Inogen (INGN) as unwarranted and recommends buying the shares at current levels. The analyst says his firm's survey of 66 home medical equipment providers indicates the shift to portable oxygen concentrators "remains strong." The market remains in the early innings of this conversion and Inogen is the best way to play this thematic trend, McKim tells investors in a research note. The analyst expects ResMed's (RMD) Mobi to launch this year, but does not expect it to be overly impactful to Inogen. Consensus numbers already reflect a deceleration in growth in the second half of 2018 which is unlikely to materialize, McKim contends. He keeps an Overweight rating on Inogen with a $190 price target.