In Swedish patent law, there's a clear statement that for an application to be approved, the solution that it provides can't be "obvious to an industry professional". Meaning that, given the state of technology at the point of application, if the solution could be expected by any professional of the field — it is not valid. Is there equal or similar statements in US patent law?
Yes. 35 U.S.C § 103, known as the nonobviousness provision, provides that "[a] patent for a claimed invention may not be obtained . . . if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made."
Effectively what this means is that even if your exact invention didn't appear in a single piece of prior art, if the prior art contained all the individual elements and there would have been some reason for a person having ordinary skill in the art (PHOSITA) to combine them, then the invention is invalid for obviousness.