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

Surgical performance with head-mounted displays in laparoscopic surgery

INTRODUCTION

The difficulties of laparoscopic surgery include two-dimensional image projection and loss of alignment between the surgeon's hands and visual field. Head-mounted displays (HMDs) allow freedom from gazing at a stationary overhead monitor, thus improving ergonomics. Modern HMDs offer greatly improved image quality and reduced bulk and weight. We compared two types of HMDs with conventional overhead image display.

MATERIALS AND METHODS

Twelve preclinical medical students (i.e., laparoscopic novices) completed the standardized bead-passing task in a Fundamentals of Laparoscopic Surgery box trainer, using a wall-mounted monitor(WALL), a solid-state high-resolution dual full-visual graphic array (VGA) HMD (HIGH-HMD), or a lightweight commercial 1/4 VGA HMD (LOW-HMD). Participants performed each task by using the three image displays. The order in which they performed each test was randomly assigned to minimize the carryover effect.Students were then asked to grade comfort and image quality on a scale from 1 (worst) to 5 (best). Statistical comparison of the time per bead was performed with the Kruskal-Wallis test, and P < 0.05 was considered significant.

RESULTS

Average time per bead (total beads = 12/participant/test) was 14.2 seconds for WALL, 13.2 seconds for LOW-HMD, and 12.5 seconds for HIGH-HMD (P 0.05). The comfort ratings were 3.67 +/- 0.82, 3.50 +/- 1.38,and 3.83 +/- 0.75, respectively, and image quality was rated as 3.00 +/- 0.63, 2.83 +/- 1.47 and 4.67 +/- 0.52, respectively.

CONCLUSIONS

The high-resolution HMD offered significantly better image quality and allowed faster task performance than a lower resolution model of HMD, and both performed better than the overhead display. The high-resolution HMD was not significantly more comfortable than the low-resolution model, given its added weight. HMDs alone may only be of incremental benefit in improving performance in laparoscopic surgery.However, their greatest promise is in their combination with other advances in imaging and image manipulation technology, as they open the door to individualized image display.

Technologies and Solutions for Data Display in the Operating Room

Recent advances in technology have led to the introduction of a variety of innovative devices, each with their own platform for data display, into the operating room (OR). While these innovative applications are expanding the traditional boundaries of the surgical space and enhancing treatment capabilities, the introduction of additional screens and displays is placing an ever-increasing load on the OR team. This review describes the main data display platforms currently available in ORs: computer monitors with CRT (cathode ray tube) or LCD (liquid crystal display) screens, suspended imaging displays, wearable computers (WC), auditory displays and tactile (haptic) displays. The different display platforms are evaluated according to their compatibility with the characteristics of the working environment (OR), the monitoring task, and the users (the surgical team). No single display configuration provides an ultimate solution for presenting patient data in the OR. A multi-sensory data display including visual, acoustic and haptic manipulation is suggested as a promising configuration for data display in the OR.

Reducing errors in the operating room: surgical proficiency and quality assurance of execution

Technical operative errors cause surgical operative morbidity and adversely affect the clinical outcome of patients. Surgical proficiency thus underpins good and safe practice. In this context, standardization of endoscopic surgical operations and their execution are essential for the procurement and maintenance of quality assurance in endoscopic surgical practice. There is no clash between individual- (surgical proficiency) and system-based defense systems in the prevention of surgical errors--both underpin safe surgical practice. Although more human factors and surgical research are needed, it is possible to formulate and adopt a surgical error reduction system for endoscopic operations based on standardization of operations, surgical operative proficiency, and human reliability assessment and its related clinical counterpart, observational clinical human reliability assessment.