You undoubtedly know more about this than I do, but every element of the claim (loosely speaking, everything before a semicolon) has to be found in the prior ar

You undoubtedly know more about this than I do, but every element of the claim (loosely speaking, everything before a semicolon) has to be found in the prior art. And there has to be some reason why a person of ordinary skill in the art would have thought to combine them. It IS tedious, but your paragraphs would get absolutely no traction with the PTO. The applicant has to disclose all the prior art he's aware of. This is often abused, but for a well-known technology area, it wouldn't do to say "I don't know of any." Indeed, at the end of this patent there are a whole bunch of references to other "oximetry" patents. If the patent somewhere points out why what they're doing isn't found in the prior art, I missed it.