Prince Philip emerged from the King Edward VII Hospital in central London this morning with a smile and wave for the waiting media, after spending five nights there being treated with antibiotics for a bladder infection.As he left, the Prince waved to well-wishers, shook hands with staff at the hospital and thanked them for their care.When asked if he was feeling better, he said: “I wouldn’t be coming out otherwise.”He is now expected to celebrate his 91st birthday privately on Sunday with the Queen and other members of the Royal Family at Windsor Castle.