Choosing Surgical Lighting in the LED Era

Background. The aim of this study is to evaluate the illumination characteristics of LED lights objectively to ease the selection of surgical lighting. Methods. The illuminance distributions of 5 main and 4 auxiliary lights were measured in 8 clinically relevant scenarios. For each light and scenario, the maximum illuminance E-c (klux) and the size of the light field d(10) (mm) were computed. Results. The results showed: that large variations for both E-c (25-160 klux) and d(10) (109-300 mm) existed; that using auxiliary lights reduced both E-c and d(10) by up to 80% and 30%; that with segmented lights, uneven light distributions occurred; and that with colored LED lights shadow edges on the surgical field became colored. Conclusions. Objective illuminance measurements show a wide variation between lights and a superiority of main over auxiliary lights. Uneven light distributions and colored shadows indicate that LED lights still need to converge to an optimal desig

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 lightin

Changes in volunteering among the young old in the Netherlands: The impact of religion, age-norms and intergenerational transmission

The positive trend in volunteering among the Dutch young old may in part be due to a relatively favorable disposition to volunteer. Using data from the Longitudinal Aging Study Amsterdam, volunteering rates of 55-64 year olds in 1992 and 2002 were compared and associated with (among others) three types of dispositional factors: religious involvement, age-related engagement norms, and parental socialization. The recent cohort was less religiously involved, but more supportive of social engagement at older age, and more often had parents who volunteered, were religiously involved or higher educated. Multivariate analyses revealed that cohort differences were largely explained by cohort differences in educational level and religious involvement. It is concluded that their lower religious level suppresses the volunteering rate of the current young old. To compensate for the decline in religious young old, family and the broader society will become more important for stimulating volunteer work in the future