Optimizing Color Performance of the Ngenuity 3-Dimensional Visualization System.

PURPOSE

To evaluate the effect of surgeon-controlled parameters on the color performance of the Ngenuity 3-dimensional (3D) visualization system.

DESIGN

A calibrated reference target was placed inside a model eye to assess the Ngenuity 3D camera under different settings. The Ngenuity 3D display was assessed with a commercial colorimeter.

METHODS

Manufacturer-recommended methodology for white balancing was compared against all common deviations in technique. Following white balance, images of a calibrated reference target were extracted and tested using Imatest Master software to calculate quantitative color differences (delta E and delta C). The Ngenuity monitor was assessed using a SpyderX Elite commercial colorimeter to assess for image burn-in by quantifying color uniformity and maximum luminescence.

MAIN OUTCOME MEASURES

Delta E and delta C were calculated for all variables. Color uniformity and luminance were assessed in candelas per square meter (nits).

RESULTS

Color performance using the manufacturer-recommended specifications yielded a delta E of 12.81 ± 1.67. Changing the white balance target to a videography grey card ( = 0.07) and 4 × 4 gauze ( = 0.37) provided similar performance, whereas using white computer paper or the operator's palm significantly increased the delta E from 12.81 ± 1.67 to 15.28 ± 1.22 ( = 0.01) and 17.71 ± 2.03 ( < 0.01), respectively. Changes to card position, magnification, stability, or ambient lighting did not significantly impact white balance results, whereas having the card in crisp focus did decrease color accuracy (15.78 ± 1.63;  = 0.03). Minor improvement in performance occurred when the laser filter was off for white balance and image acquisition (9.28 ± 0.25;  < 0.01), but deterioration occurred if the laser filter was placed after balancing (16.59 ± 1.17; < 0.01). Both light sources of 23-gauge light pipe at 34% intensity and 25-gauge chandelier at 50% intensity gave similar color accuracy ( = 0.37). When comparing different Ngenuity machines, color uniformity and maximum luminescence decreased with increased device use.

CONCLUSIONS

Overall, the Ngenuity 3D has robust color performance. A few limitations of both the camera and monitor were identified, and surgeons should be aware of these pitfalls as well as solutions examined herein to mitigate their effects during surgery.