Standards and Performance Indicators for Surgical Luminaires

The illumination performance of surgical luminaires is quantified by performance indicators defined in an international standard (IEC 2000). The remaining maximum illuminance in relevant situations, the light-field size, and the spectral characteristics are performance indicators used by hospitals as input for luminaire opting processes. Industry however focuses on illuminance when communicating with health care professionals. The aim of this study is to evaluate whether these standards are sufficient to describe luminaire performance, especially for modern LED lighting technology. Illuminance distribution and spectrum measurements were performed on 5 different state-of-the-art ( LED) surgical luminaires. The results showed that changing situations not only changed the maximum illuminance but also changed the light-field sizes and shapes, introducing substantial differences between luminaires. Moreover, colored cast shadows and light color variations across the light-field were observed for 3 luminaires using differently colored light emitting diodes (LEDs). Both the changing light-field sizes and shapes, and the cast shadows and light color variations for LED luminaires are not covered by the current standard. The standard should therefore be extended to incorporate these aspects, especially for such a high-end application as surgical lighting.