Daylight and artificial light spectral analysis:

Daylight, defined as the sum of direct and indirect solar irradiance was collected through a calibrated spectrometer with peak sensitivity range of 350–800 nm (STS-VIS, Ocean Insight, Orlando, FL). We mounted the spectrometer on a mast located 25 feet above the roofline of the 14 story Cincinnati Children’s Clinical Sciences Pavilion located about 500 feet from the CCB. The location allows for 97.5% coverage from horizon to zenith in all directions. Minimal shadowing (2.5%) is due to an air terminal for lightning protection located a few feet north of the spectrometer detector. The detector is a 1024-pixel CMOS device equipped with cosine corrector housed in a weather protection dome and connected to the spectrometer via fiberoptic cable. Data was collected every 10 minutes and downloaded to data acquisition software. In addition, we obtained spectral measurements of the standard ambient lighting found in the former CCHMC NICU (“old NICU,” closed in November 2021) and the CCB NICU (“new NICU”). These measurements employed a custom-built spectrometer designed and manufactured by Ocean Insight. This device contained four STS-VIS spectrometers to capture irradiance from a variety of locations within the NICU environment including open cribs, radiant warmers, and isolettes (with and without coverings). Additional details regarding the lighting detection systems are provided in Cao et al. (submitted for publication).