Atlanta-based Grady Memorial Hospital is expected to announce a new CEO to run the troubled medical center in August, and will bring the new leader on board in September, officials said. Pete Correll, head of the hospital board of directors, acknowledged that the hospital missed its self-imposed deadline to name a new chief officer in June and said the search has proved more difficult than expected. Some candidates were deflected by the Georgia law requiring that the names of finalists for such public positions be made public, and others did not want current employers to know they were looking only to be passed over, he said.