FDA's top medical device reviewer is stepping down to take a job in Microsoft's lobbying office.

Donna-Bea Tillman told staffers in a note she is resigning as director of the office of device evaluation, after 15 years with the FDA. Tillman said she will serve as director of regulations and policy for Microsoft Corp.'s health information unit. In the note to staffers, Tillman said that after several interviews, it became clear that this was the right next step to take.

Tillman was one of several FDA officials criticized by lawmakers for their handling of the knee repair device, Menaflex, made by ReGen Biologics Inc. The device was approved in late 2008 despite repeated objections from FDA scientists who questioned its safety. However, Tillman maintains that her departure is not related to the ReGen issue.

At Microsoft, Tillman plans be part of the company's effort to beef up the development of medical information-technology systems and expand the profile of its health group in Washington.