Monitor height ergonomics: A comparison of operating room video display terminals

A surgeon's eyes should be positioned 1 meter (m) distant and no more than 15 degrees below the top of an operating monitor (0.27 m). We sought to determine which operating room video display terminal can best accommodate ergonomically optimized gaze during surgery. Floor to eye height was measured for surgeons in seated, perched, and standing positions. These ranges were then compared to vertical displacement ranges for monitors measured from floor to top of the screen. Eye height was measured for standing (1.56 - 1.80 m), perched (1.40 - 1.65 m), and seated (1.10 - 1.32 m) positions. The minimum distance (min) between the floor and the top of the monitor and the vertical mobility range (VR) of the monitor were measured throughout a tertiary medical center including towers with boom arms (TcB) (min: 1.58 m, VR: 0.37 m), towers without booms (TsB) (min: 1.82 m, VR: 0.025 m), ceiling mounted booms (CMB) (min: 1.34 m:, VR: 1.04 m), and portable monitors (PM) (min: 1.73 m, VR: 0.04 m). The tangent of 15 degrees declination was used to calculate a correction factor to determine the minimum optimal ergonomic display height. The correction factor was subtracted from the eye height at each position to determine the lowest target height and the highest target floor to eye distance for each position. Analysis of variance with least significant difference post hoc testing identified all minimum distances and vertical ranges to be statistically different (p < 0.001). Monitor vertical displacement varied between styles of carts. CMB video display terminal systems can accommodate standing, perched and the tallest seated surgeons. TcB, TsB and PM systems cannot adequately accommodate all standing, perched or seated surgeons.