Dean submitted his 510K application for the DViS in June of 2007. I don't recall the dates of the AI requests between then and December of 2009 when the old review team was replaced with the current one. However, Dean was told late last year by one of the Directors (who was replaced along with the old reviewer and her boss)that he would approve his device if he would clarify the "intended use" statement in the DViS manual. Dean complied and was awaiting a response when the old team was ushered out and the new one ushered in.
In January (I believe) of this year, he was contacted by the new review team and presented with a list of 18 questions that they had compiled (AI). He was also asked to include a third party radiologist's review to make it easier for them to approve the DViS. Dean was at first hesitant, not wanting to go down the PMA route. After being told that was not their intent, Dean set out to respond to their requests.
Most of the questions were answered very quickly, but the radiologist's review took some time and, upon completion, was sent to the FDA on April 5th of this year. The FDA acknowledged receiving the package on 4/9, but, apparently, didn't stamp it received until 4/14 (?).
Dean was then contacted in early July by the FDA because they were having issues opening some of the complex image files he had sent, along with not knowing where to insert the third party radiologist's review. The FDA was also contacting him regularly about questions the old review team were asking. That is when Dean decided (on his own, not an FDA request) to send them a whole new package explaining how to open the files, where the radiologist's review should be inserted, and annotating any issues brought up by the old review team (anticipating future questions based on what the new team was asking). This was not considered AI and the clock was not stopped.
Sorry this took so long. I hope it helps.