Proposed changes to the U.S. system for regulating medical devices are more objectionable to the industry than some local experts expected. Late Tuesday, the Food and Drug Administration issued a lengthy set of recommendations for changing its 501(k) review program, by which the government considers whether to clear for sale in the U.S. moderate-risk devices such as MRI machines and noninvasive blood-pressure monitors. "Up until this point in time, FDA has been saying that this round of proposals would be noncontroversial, things everyone would agree with by consensus," said Ralph Hall, a law professor at the University of Minnesota who previously worked for industry. "These (recommendations) include more than noncontroversial consensus items." Among the changes proposed Tuesday, FDA called for creating a new subset of moderate-risk devices for which clinical or manufacturing data typically would be necessary to win marketing clearance from the government. That proposal is controversial, Hall said, because existing data about safety problems with the devices doesn't support the creation of a new category.