Hospital Lighting

Dynamic lighting designed to promote healing and wellbeing

It has been long known that light affects people’s mood and sense of wellbeing. So why not use it effectively in a healthcare setting to enhance the healing environment and promote the wellbeing of patients and staff?

In a major and often cited study – ‘The impact of light on outcomes in healthcare settings’, Anjali Joseph. PhD. (the Center for Health Design, 2006) – the researchers note in their key findings that “light impacts human health and performance by enabling performance of visual tasks, controlling the body’s circadian system, affecting mood and perception, and by enabling critical chemical reactions in the body. Studies show that higher light levels are linked with better performance of complex visual tasks and light requirements increase with age. By controlling the body’s circadian system, light impacts outcomes in healthcare settings by reducing depression among patients, decreasing length of stay in hospitals, improving sleep and circadian rhythm, lessening agitation among dementia patients, easing pain, and improving adjustment to night-shift work among staff. The presence of windows in the workplace and access to daylight have been linked with increased satisfaction with the work environment. Further, exposure to light is critical for vitamin D metabolism in the human body. Light exposure also is used as a treatment for neonatal hyperbilirubinaemia.

Research has shown that the more time patients spend in daylight, or artificial light that mimics natural light, the better is their biological response to healing and therapy. The research showed that light can improve patient satisfaction, comfort, mood and quality of sleep – all factors that can speed up recovery from illness or surgery.

The effect of light on a person’s biological clock is also important as it influences many aspects of their physical and emotional wellbeing. This biological clock is regulated by light and darkness, by the daily cycles of night and day and the time a person spends asleep and awake. Those who have to stay indoors for significant parts of their time, like hospital patients, can be particularly at risk of getting insufficient light during the day to set their biological clock properly. “By controlling the circadian system, light – both natural and artificial – impacts many health outcomes among patients and staff in hospitals such as depression, sleep, circadian rest-activity rhythms, as well as length of stay in the hospital,” says Anjali in his research paper. When looking at the influence of lighting on decreasing the length of stay in hospital, Anjali cites several studies. Beauchemin & Hays (1996) and Benedetti et al. (2001) documented the impact of light on length of stay among depressed patients. A couple of other studies suggest that exposure to light may be linked to length of stay among clinically nondepressed patients as well. A retrospective study of myocardial infarction patients in a cardiac intensive-care unit treated in either sunny rooms or dull rooms found that female patients stayed a shorter time in sunny rooms (2.3 days in sunny rooms, 3.3 days in dull rooms) (Beauchemin & Hays, 1998). Mortality in both sexes was consistently higher in dull rooms (39/335 dull, 21/293 sunny). Another study found that Veterans Health Administration medical centers located in warmer and drier climates had shorter length of stay of patients (Federman, Drebing, Boisvert, & Penk, 2000). Hospitals in colder climates had longest lengths of stay in winter and fall.


Building on this research Philips took up the challenge to develop dynamic lighting for the hospital setting in an effort speed up patient recovery and promote patient wellbeing. Of course it was a natural step for Philips to innovate in this field as they could relatively easily combine expertise from two of their major interests – lighting and healthcare. The company proceeded to develop a dynamic lighting solution called HealWell for hospital rooms. The lighting solution makes use of an intelligent networked control system. It automatically manages a rhythm of dynamic daylight – dynamic shades of warm and cool light – in the patient room to support patients’ biorhythms throughout the day. It also allows patients and staff to control settings individually. HealWell produces lighting levels that change gradually throughout the course of the day, much like the changes in light outdoors on a sunny day, and this affects sleep and mood. In a sense it mimics the natural day/night cycle outdoors.

Sleep-wake rhythm

The Maastricht University Medical Center (Maastricht UMC) in the Netherlands has carried out research in partnership with Philips to investigate the effect of light on the sleep-wake rhythm of cardiac patients. The research shows that after seven days in a patient room fitted with HealWell patients sleep on average 8% longer. After one week in a patient room fitted with standard lighting, on the other hand, patients’ sleep duration was in fact slightly shorter than on the first night.

Sleep essential part of recovery process

Existing scientific research has shown that high levels of light during the day help to regulate the human biological clock and the sleep-wake rhythm. If a person’s biorhythm is less than optimum, this can disrupt sleep and give rise to a variety of health problems. Philips HealWell combines the positive biological effects of natural daylight with a pleasant atmosphere in the patient room. This has a positive effect on the patient’s sleep patterns and that in turn has a positive effect on their biorhythm, which is important for their health and wellbeing.


The research has demonstrated some significant improvements: the time it takes a patient to fall asleep is reduced by approximately 30% during the period between the first and the seventh night and at the same time the duration of sleep at night increases by on average 8%. This means that a patient sleeps on average 30 minutes longer. The research also shows that patients really appreciate being able to select the ambient lighting themselves. The healthcare personnel were also very impressed with the Philips HealWell lighting, partly because of the better light distribution over the entire bed without any annoying shadows.

Maastricht UMC research

The Maastricht UMC, the Clinical Trial Center Maastricht and the University of Maastricht spent more than nine months carrying out research into the effects of the Philips HealWell system on sleep and wellbeing among patients. This dynamic lighting system was installed in a number of patients’ rooms in the hospital’s Cardiology department. More than 100 cardiac patients took part in the survey, whereby one group was treated in patients rooms fitted with the Philips HealWell system and the other group, the control group, was treated in patient rooms equipped with standard lighting.

“We can now tell from the results of the Philips HealWell research that better light during the day enables patients to sleep longer at night,” says Dr Petra Kuijpers, cardiologist at the Maastricht UMC. “The patient’s mental state is an important factor that influences the prognosis for cardiac patients, and light could have a positive effect on this, as well as on the patient’s health in the long term. This is, however, an area in which further research is required. What the positive results of the clinical validation research demonstrate is the valuable role the HealWell lighting solution can play in improving the healing environment and promoting the recovery of our patients.”

Commenting on the research, Dr Luc Schlangen, Senior Principal Scientist at Philips Lighting, said: “The research into HealWell at Maastricht UMC ties in with the findings of earlier research, which found that light has a positive effect on health, mood and well-being, not just for people in a care environment but also for healthy people.

“The Maastricht research is the first of a number of research projects that are already in progress or are in preparation in hospitals, such as in the new intensive care unit at the Jeroen Bosch hospital in Den Bosch and in the Hematology department in the Erasmusziekenhuis in Rotterdam. We will use the insights we have gained into the experiences of patients and caregivers to develop meaningful innovations that will improve people’s lives.”

Hospital lighting survey

In other recent research, which confirms the importance of daylight lighting in the hospital environment – Safaa Alzubaidi, Susan Roaf, P. F. G. Banfill of the School of the Built Environment, Heriot-Watt University, Edinburgh, United Kingdom and Raidh Ali Talib, Abdullah Al-Ansari of the Urology department, Hamad General Hospital, Doha, Qatar, conducted a survey – published in the International Journal of Energy Engineering 2013, 3(6). DOI: 10.5923/j.ijee.20130306.02 – to review the subjective judgments of hospital staff lighting needs and satisfaction.

The researchers write that:

Responses obtained from 134 staff showed that 79% of the participants identify daylight in patient’s room as a factor helping them do their work more easily, and 77% of the surveyed nurses and doctors claimed that daylight is an important element in patient rooms to aid in reviewing patient recovery through recognizing and interpreting changes in patient skin colour. Seventy eight percent of hospital nurses and all the surveyed doctors believe that daylight has many health benefits including fast recovery and reduced length of stay for patients. Moreover, 92% of the surveyed staff stated that patients preferred to stay in rooms with access to daylight as it makes them feel comfortable.

They point out that these results should be taken on board by hospital designers and regulation makers as an indication of the importance of using good daylight in hospital wards to achieve two important goals of improving both hospital staff working conditions and the patient’s healing environment.

Further reading:

1. “The impact of light on outcomes in healthcare settings” – Anjali Joseph, Ph.D., Director of Research, The Center for Health Design

2. “Healthcare design insights – daylighting” – MahlumHDIAutumn2009Issue01.pdf

 Date of upload: 14th Nov 2014


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