The opportunities of biodynamic lighting in homes for the elderly

Abstract

Abstract Light is an important factor for regulation of circadian, endocrine and metabolic processes in the human body. Through this light has a positive effect on cognition, on the stabilization of circadian rhythms and for general wellbeing. These effects are described as non-visual effects of light. Many dynamic lighting systems are already in use in workplaces and living spaces, aiming to address visual and also non-visual effects. In Europe and US the term “Human Centric Lighting” or abbreviated "HCL” was introduced, as a scientifically agreed concept on how to plan non-visual effects of artificial light in synergy with natural light. Older people, especially with neurological and psychological diseases can especially benefit from this lighting concept. However, in order to achieve the desired non-visual effects, certain conditions should be fulfilled. In Germany the DIN SPEC 67600 is a guideline for the design of biologically effective illumination, with examples for senior- and nursing homes. A goal of this evaluation was to check whether the recommendations of the specification DIN SPEC 67600 in three nursing homes were met and another goal was if effectiveness of the lighting on residents and nursing staff can be determined. Photometric measurements were taken and subjective perceived non-visual effects of light were surveyed using a questionnaire. Results: Although none of the three facilities met all the criteria of the DIN SPEC 67600 guidelines, non-visual lighting effects on residents and nursing staff could be detected. The results also indicate that careful attention should be paid on maintenance of HCL systems. The correct use of HCL solutions in homes for the elderly has opportunities to improve health status if the system is properly designed and maintained. Therefore next to the existing (non-visual) metrics and HCL design guidelines, guidelines for maintaining and regular inspections should be established.