A Review of Parameters and Techniques in Human-Centered Integrative Lighting

Natural and artificial lighting have the ability to produce visual and non-visual effects on human beings. There are four well-known photoreceptors: cones on one hand, and L, M, and S type rods on the other, which are associated with the visual system and allow for a differentiation of color and tone of objects based on reflected light. On the other hand, non-visual effects depend on another recently discovered photoreceptor known as Intrinsically Photosensitive Retinal Ganglion Cells (ipRGC), which when excited primarily suppress melatonin, a hormone that regulates Circadian Rhythms (CR), and can also affect biological and psychological processes. This work presents a study on integrative lighting, focused on the analysis of methods and parameters for calculating factors used in lighting design, such as Circadian Stimulus (CS), Equivalent Melanopic Lux (EML), etc., and their combination with traditional lighting design parameters such as Color Rendering Index (CRI), Correlated Color Temperature (CCT), chromatic coordinates, TM-30 color standard, among others. Furthermore, emphasis is placed on the use of the CIE-S-026:2018 standard, which establishes sensitivity curves associated with photoreceptors of the human visual system. It is determined that the Melanopic Illuminance parameter (m-EDI) is currently the determining factor for evaluating non-visual effects. Thus, a parameterization methodology is proposed in order to design a Human-Centered Integrative Lighting System (HCILS).