Which Factors Affect the Stress of Intraoperative Orthopedic Surgeons by Using Electroencephalography Signals and Heart Rate Variability? - Ji-Won Kwon; Soo-Bin Lee; Sahyun Sung; Yung Park; Joong-Won Ha; Gihun Kim; Kyung-Soo Suk; Hak-Sun Kim; Hwan-Mo Lee; Seong-Hwan Moon; Byung Ho Lee (Sensors, 2021)