Design and Control of an Upper Limb Exoskeleton Robot RehabRoby. - Fatih Özkul; Duygun Erol Barkana (TAROS, 2011)

Exploring dynamic difficulty adjustment mechanism for rehabilitation tasks using physiological measures and subjective ratings. - Fatih Özkul; Yunus Palaska; Engin Masazade; Duygun Erol Barkana (IET Signal Process., 2019)

Dynamic Difficulty Level Adjustment Based on Score and Physiological Signal Feedback in the Robot-Assisted Rehabilitation System, RehabRoby. - Fatih Özkul; Duygun Erol Barkana; Engin Masazade (IEEE Robotics Autom. Lett., 2021)