Application of Human Factors in Surgery: Studies on Technique, Displays, and Performance.

Abstract

The overall goal of this work is to develop a framework that can be used to describe surgical procedures, measure performance, and identify ergonomic risk factors that may affect surgical outcomes and musculoskeletal stresses. Variations in technique commonly exist in surgical procedures; however, clinical evidence to support one technique over another is limited. Identifying best methods in surgical techniques and visualization equipment can reduce the risk factors for musculoskeletal fatigue among surgeons while improving surgical outcomes. This work presents a taxonomy that systematically quantifies differences in techniques among surgeons and cases. Using observed variations among surgeons, hypotheses were formulated on the relationship between different methods and outcomes that can be tested in future studies. The taxonomy was also used to formulate hypotheses on ergonomics factors that may impact surgeon’s musculoskeletal stresses and performance. Hypotheses on the effect of alternative video displays on postures and performance were tested in the laboratory setting. Results found that neck angles were significantly more erect on video displays than microscopes during simulated microsurgery skill tasks. In addition, more neck and shoulder movements were observed on the video displays than microscopes. Performance times on video displays were slower than microscopes and loupes. However, differences in performance times were smaller on the x (left/right) and y (fore/aft)-axes than the vertical z-axis. In addition, video displays were not significantly worse than other displays in overshoot and distance moved metrics that may be indicative of mechanical stress blood vessels may be exposed to in microsurgery. Contribution of this work includes: 1) development of a taxonomy for identifying best methods among variations in surgeon techniques that can be used for evidence-based training and assessment, 2) determining the impact of visualization equipment on surgeon’s risk for musculoskeletal symptoms and fatigue, and 3) measuring the impact of video displays on simulated microsurgery task performance and the limitations of such displays in surgery. Application of this work can be used to improve outcomes for both patients and medical practitioners during surgical procedures.