Bedford’s iRobot Corp. has won FDA clearance for a line of robots designed to let doctors interact with hospital patients remotely. RP-VITA is designed to navigate around hospitals on its own and has a 15-inch LCD screen as a face. The first RP-VITA robots, which would cost hospitals $4,000 to $6,000 a month to operate, could begin appearing in medical centers in the next few months. IRobot developed the robots in partnership with InTouch Health Inc., a California company.