The Food and Drug Administration is laying out plans to update the 35-year-old system used to approve most medical devices, which has been subject to increasing criticism by public safety advocates. The agency announced a series of changes it plans to make this year, including streamlining the review process for some low-risk devices. But regulators said they will delay a decision on the most drastic proposals, which would give the government new power to police device makers. Those proposals, widely supported by public safety advocates, included clarifying the FDA's power to revoke approval for products that prove unsafe or ineffective. Another key proposal would have established a new subset of devices that would require more medical data to gain approval.