You can try DS-7000 Professional Dictation System from Olympus or Olympus DS-3500, ,they both provide a real-time file encryption and password protection.
John, I've always used a simple digital recorder too. I interview patients and they often tell me sensitive and confidential information about their own health. The uni wants us to be extra careful, specially when driving to and from patients' homes with their confidential data (in case it gets lost in transit!) Carole, I'll ask Claire! ;-) Thanks Oussama! Very useful!