Hiya, Sorry that I just pick up this post now.
Goldway has just released the latest new version of UT4000F, which has the Philips SpO2 and MicroStream CO2, on very affordable cost with Philips quality guaranty. http://www.ebme.co.uk/products/index.php?prod_id=160
I think you should have the old version. Please do send me an email so that I could guide you. Or you are always welcome to contact Goldway.Service@philips.com , it should help you much better.