PNNL studies nurse experience to tunable SSL in hospital patient room

April 19, 2021
Tunable and dimmable primary lighting along with color-tunable wall washing in a simulated hospital patient room delivered mixed results in a DOE-funded study.

A US Department of Energy (DOE)-funded solid-state lighting (SSL) research experiment in a simulated hospital patient room has moved through a phase where nurse reactions to an advanced tunable lighting installation was evaluated. Pacific Northwest National Laboratory (PNNL) has led the experiment that will ultimately include evaluations from simulated patients’ perspectives. The participants clearly favored the multi-zone systems with complex controls over a legacy room design where a single luminaire located over a patient bed provided the sole room lighting. But the experiment with tunable spectra did not draw strong positive results in terms of circadian comfort or perception among the nurses.

The PNNL experiment was first published in the academic journal Health Environments Research & Design. The complete report is also available on the DOE SSL website. The PNNL worked with researchers at the Georgia Institute of Technology (Georgia Tech) SimTrigate Design Lab on the project. The methodology involved having participants, nurses and students, perform simulated clinical tasks working in the simulated patient room under 13 different lighting conditions.

The work was based around the theory of environment of care, or more specifically the environment in a patient room including the lighting that was designed and implemented to enhance the delivery of care. Older hospitals with basic on-off lighting are said to offer a TEC (traditional environment of care) designed more for the healthcare provide than the patient. A room that adds some patient-focused comfort features such as daylighting and perhaps dimming is said to offer a CEC (contemporary environment of care).

The simulated patient room can afford a FEC (future environment of care) through full dimming, spectral control, and amber nighttime navigational lighting. We have covered a number of examples of such patient-focused human centric lighting including in a Denmark hospital a few years back when nurses pushed to install such lighting.

The experiments documented in the new report were intended to evaluate the nurses’ perception of bright cool-CCT lighting that might synchronize the circadian system, lighting scenarios that simulate the range of environment of care, and the use of color-tunable ambient wall washing.

The simulated room included the primary patient bed area with a lighting zone directly above the bed. To one side, it includes a sitting area with two chairs and a table with a separate lighting zone. And on the opposite side it included a nurse work area that did not include separate dedicated lighting. The color-tunable wall washer illuminated the wall opposite the patient bed. The navigation light was mounted along what would be the typical path from the patient bed to the restroom.

The tests concocted for the research included various evaluations of visual acuity. For instance, the nurses were told to locate the appropriate pill bottle based on the label from among 13 bottles. There were other color and word identification tasks. The report details all of the tests and the 13 lighting conditions.

The results summary for the first phase of the experiment is frankly underwhelming. But in retrospect, that statement is not surprising because even TEC- and CEC-class rooms were designed for the healthcare professionals to effectively work in. It will be interesting to see a phase of testing simulating the patient perception of the FEC environment.

The nurses did not rate the cool-CCT conditions well in terms of comfort and perception. Of course, that setting would be targeted at synchronizing the patient’s circadian systems. And it would not necessarily be used when nurses are actively delivering patient care.

The nurses did value the ability to use dim settings of the primary lighting to perform tasks at night. And the multiple zone approach was much preferred compared to TEC and CEC simulations where the zonal functionality was eliminated. But the nurses did not value tunable white spectra. And they generally rated the color-capable wall washer negatively relative to white lighting.

Signify provide the lighting systems used in the simulated room. We will eagerly await future results from a patient perspective. Of course, the data from the nurse perspective is also valuable. As speakers at our 2017 Lighting for Health and Wellbeing covered, nurses working night shifts are very much subject to circadian disruption and a long list of maladies.

LEDs Magazine chief editor MAURY WRIGHT is an electronics engineer turned technology journalist, who has focused specifically on the LED & Lighting industry for the past decade.


E. Graves et al., “Lighting the Patient Room of the Future: Evaluating Different Lighting Conditions for Performing Typical Nursing Tasks,” Health Environments Research & Design, OnlineFirst (Nov. 24, 2020).

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