 Commander Katherine Pulaski is a fictional medical doctor in the American science fiction television series Star Trek : The Next Generation . She is the chief medical officer aboard the Federation starship USS Enterprise @-@ D. Her medical skills saved the lives of Captain Jean @-@ Luc Picard and Commander William Riker , and she helped inspire Lt. Commander Data to create a hologram of Professor Moriarty that became self @-@ aware . Pulaski preferred to avoid the transporter , but was forced to rely on it to save her own life from an alien infection . Before arriving on the Enterprise @-@ D , she previously served on the USS Repulse . For a time , she was romantically involved with Kyle Riker , but they continued to remain friends . 
