其实家用的在美国也不那么贵，亚马逊上有一个，$429. （可能还有$30 折扣）。

https://www.amazon.com/Oxygen-Concentrator-Therapy-Device-High-Performance/dp/B0B88GF9FV/ref=asc_df_B0B88GF9FV/?tag=hyprod-20&linkCode=df0&hvadid=632204005385&hvpos=&hvnetw=g&hvrand=1473900591108027402&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9032144&hvtargid=pla-1894691506067&psc=1&region_id=674469