Optimization of the projection screen in a display system for minimal access surgery

Background: The operative image for minimal access surgery currently is displayed on a monitor located outside the sterile field. It is ergonomically advantageous to locate the image adjacent to the surgeon’s hands by projection onto a sterile screen, but there has been no research into the optimal screen material. Methods: Several screen materials were compared for image resolution, brightness, variation of brightness with viewing angle, and image artifact. Results: Glossy materials perform poorly, whereas finely grained surfaces improve image clarity. Excessive roughness and incomplete opacity limit the image resolution. Conventional screen fabrics are unsuitable in this application. Ambient lighting and projector brightness affect image contrast, but a correct choice of material can address this. Practical issues such as moisture absorbency and ease of sterilization are considered. Conclusions: Potential screen materials were rejected because of excessive glare, poor resolution, and image artifact. Finely textured surfaces (e.g., polystyrene sheeting) provide an acceptable screen.