The effect of visualization method on the performance of simulated microsurgery tasks

The operating microscopes may be a significant cause of fatigue and discomfort in surgeons. The need for the microscope to be placed over the operating field forces surgeons to remain at the microscope's eyepieces at an uncomfortable posture for the entirety of the surgery. This study compared the effects on microsurgical task performance for four visualization methods: a monocular microscope, a binocular microscope, a three-dimensional (3D) flat-panel television display and a two-dimensional (2D) flat-panel television display. Eleven subjects each performed two microsurgical tasks and their performance was documented by video camera. The statistical analysis performed indicated utilization of the microscope as a visualization method increased subject performance. No significant difference in performance between the 2D and stereoscopic visualization methods.     

Quantitative posture analysis of 2D, 3D, and optical microscope visualization methods for microsurgery tasks

The purpose of this paper is to present a quantitative posture analysis of microsurgery tasks performed with different visualization methods. Microsurgery is traditionally performed using a binocular microscope; however surgeons are constrained by the optical eyepieces and are forced to assume joint angles that deviate away from neutral postures. This may be especially problematic for the neck and can increase surgeon discomfort and fatigue. Alternative visualization methods may improve surgeon posture by eliminating the constraints imposed by the microscope. This study examines both 2D and 3D heads-up displays as possible alternatives. Six subjects performed microsurgical tasks with each visualization methods for four hours. Quantitative posture analysis was done using Maxtraq software that tracks reflective markers on the subjects. The initial analysis of neck, upper arm, and elbow angles found significant differences between each display. A biomechanical analysis found that the differences in angles can result in loads on the neck joint that are twice as high in the microscope than the headsup displays. Although the alternative displays can result in better postures, improvements the display technology is needed to improve microsurgical task performance.     

Standardization of surgical procedures for identifying best practices and training

A taxonomy was developed a) to describe surgical procedures with sufficient detail to review differences among surgeons, b) to examine the relationship between individual technique and outcomes, c) to enable surgeons to standardize technique around best practices and d) to identify clinical-evidence-based key points of teaching and assessment for surgical training. Sixty-seven microvascular anastomoses were recorded through video cameras mounted in the dissecting microscope. A hierarchical task analysis was used to decompose the observed procedures into successive levels of detail. The results were then presented to individual and small groups of microvascular surgeons to help define steps and step attributes necessary to describe a procedure so that other surgeons can perform the procedure exactly the same way. Coincidently, it was found that because the surgeons' attention is confined to a very small field of view in which they can see only the veins and arteries and the ends of their instruments, they often have difficulty communicating with others in the operating room. Analyses of selected cases using the proposed taxonomy shows how subtle details are revealed that may affect outcomes, and indicate specific training needs. By comparing different methods and outcomes, it should be possible to identify best practices for given conditions.     

Gender differences in the ultimatum game

I explore the behavior of men and women in the ultimatum game. In one treatment, players remain mutually anonymous. In the second treatment, players'gender is common knowledge. Average offers made do not differ based on the gender of player 1. Offers are affected by the gender of player 2, with men attracting higher offers, particularly from female players 1. Players 2 of both genders choose a higher minimum acceptable offer when facing a female player 1. These patterns led to substantial differences in earnings. Such striking differences in expectations and decisions could impact salary negotiations and other real-world transactions.