Chronobioengineering Indoor Lighting to Enhance Facilities for Ageing and Alzheimer's Disorder

Evolutionary processes generate a variety of paradoxes which must be faced in order to design the most effective structures to fulfill various human requirements and preferences. One of these paradoxes comes from the evolution of circadian rhythm systems, which are normally synchronized to the geophysical cycle of night and day and coordinate internal temporal order, but are now in conflict with modern technology and the 24/7 paradigm for urban living. Modern lighting systems have traditionally focused on providing sufficient illumination for people to navigate and manipulate their environments without regard to the side effects that lighting might have on temporal aspects of behaviour and physiology. However, studies involving shift work and other applications of artificial lighting have indicated that these side effects can be quite significant. Furthermore, when an ageing circadian system is coupled with a deteriorating physiology, the side effects of a 24/7 artificially illuminated indoor environment can be especially debilitating, especially for older adults with dementia. Chronobiology is the field of biology that examines periodic (cyclic) phenomena in living organisms, whereas photobiology is the scientific study of the interaction of light on living organisms. Chronobioengineering is an emerging field of scientific study that translates research results and concepts from these fields into practical applications. The following discussion focuses on the use of light cycles to synchronize circadian rhythms and ways human health and wellbeing can be enhanced through light-emitting diode (LED) lighting in the ageing population, specifically those with dementia of Alzheimer's type. The hypothesis is that the implementation of a lighting system specifically designed to synchronize circadian rhythms in this population will alleviate symptoms of dementia and thus enhance the quality of life for both residents and caregivers. The research team is working with a lighting industry partner to manufacture a 2′ × 2′ retrofit LED luminaire for installation at St. Francis Country House, a skilled-nursing facility near Philadelphia. Research includes working with the nursing home caregivers and administrators to establish criteria and protocols for evidence-based design research that will evaluate the efficacy of the daylight-matching luminaire.