Medical Grade Oximeter (Middlefield & San Antonio Road)

Would anyone have a medical grade oximeter that I can borrow for one day so that I can do a vigorous exercise test? This can be either a finger, or bracelet, but should be a Nonin, or Accumed oximeter. I'm a lung patient that needs to be titrated for O2 during exercise. Hospital will only do a 6 min walk test, and overnight sleep test, but advises they could do the exercise test if I want to spend the money on a stress test which I don't need. Just need titration for exercise so that I know what my O2 flow rate is. Only need the Oximeter for one day.