my husband, John, had IPF, and if you are a sufferer I wish you the best of luck and hope that a treatment is found that works for you. We bought an Airsep portable oxygen concentrator for £3K with battery in 2011 and he didn't get to use it too much as he became worse quite quickly. I am looking to sell it for a reasonable sum, (£550 ono). If you are interested at all please contact me on email@example.com and we can sort out postage or delivery for you. I live in Thamesmead, close enough to Woolwich/Charlton, London for collection of the machine if you are interested. Sadly John lost his fight in October but I am glad that he is now at peace and I feel he is whole now on the 'other side of life'