An Objective Index of Office Workers' Well-Being Based on HRV-Derived Tone and Entropy: A 4-Week Observational Study. - Koshi A; Shiga K; Sugio T; Izumi K; Minato K; Yoshimura M; Kitazawa M; Hanashiro S; Mimura M; Uchida H; Kishimoto T (Journal of occupational and environmental medicine, 2026)