Touchless monitoring in medical-surgical nursing: clinical applications of radar, camera-based and contact-free vital sign technologies: a narrative review - Sonia Das; K. Gomathi Jaganathan; Divya Upreti; Sufiya Salim Inamdar; Poonam Jadhav; Shubhangi Malavade; P. Vanaja; Tamilselvan; Jaivin Jaisingh J.; N. Prabha; Nilesh Surendra Londhe; Mohammed Umar (International Journal of Research in Medical Sciences, 2026)