Evaluation of an Augmented Reality System for Ergonomic Posture and Hands-Free Control in Robotic Surgical Operating Microscope

Traditional operating microscopes (OPMI) in neurosurgery create significant workflow interruptions with surgeons required to frequently adjust the microscope while maintaining unergonomic postures that contribute to widespread musculoskeletal disorders among surgical professionals. Modern OPMI effectively acts as a manipulator robot where the end effector is a microscope. Head Mounted Display (HMD) technology offers the potential to decouple surgeons from fixed oculars but introduces new complexities in human-machine interaction design for handsfree microscope control. This research systematically evaluated the implications of three distinct constrained head-mounted interface prototypes for hands-free control of surgical operating microscopes by examining performance trade-offs, subjective workload and ergonomic considerations for future AR-OPMI system development. A comprehensive within-subjects experimental design employed a factorial approach to evaluate three kinematically distinct prototype configurations across two actuation modes representing translational and rotational control paradigms. The evaluation was conducted on 14 participants, assessing both task performance (using quantitative performance metrics) and subjective workload (through relevant subsets of INTUI & NASA-TLX). Natural head motion analysis was also conducted which revealed distinct kinematic signatures across multiple head gesture types providing preliminary empirical targets for future multi-axis constrained system development. The findings establish a preliminary foundation for future constrained system development and provides an evaluation framework for systematic assessment of human-machine interface designs in surgical applications. The progression toward clinical validation requires systematic evaluation with expert users (surgeons) in realistic surgical scenarios, building upon the comprehensive human factors framework established in this research.