In matters of Stressors, light comes second only to poor ventilation in regards to the previously discussed SBS or Sick Building Syndrome (See “Stressors – Understanding our Environment”). Its natural form fluctuates alongside weather and seasonal change, and while not posing any immediate threat, it possesses the ability to impose a sense of discomfort, and in turn spur mood and behavioural imbalances. The sleep patterns we experience during the transition from day to night are a product of the activation of the hormone melatonin, which is dictated by our quantity of exposure to light. Therefore, a disturbance in these patterns can result in disorders such as fatigue, irritability, and hypersomnia, which may later progress into more serious cases such as heart attacks and high blood pressure.
In recent years these symptoms have been endorsed by psychiatrists as occurring as an effect of SAD or Seasonal Affective Disorder. In seasonal countries like the UK, 1 in 5 people will experience this during the months of September to April. The consistent abundance of sunlight experienced in the Caribbean makes us far less susceptible to this. However, exposure to light, whether natural or artificial, within the internal spaces we routinely inhabit such as workplaces, doctors offices, and our homes can counteract the benefits our sunny island provides as a result of poor lighting strategies.
These considerations are most valuable in healthcare as the inhabitants of these buildings are more vulnerable due to their weakened/sickly state. Though natural light is ideal, the density of the hospital typology can make it near to impossible to direct light into all spaces. In these cases, proper selection and placement of artificial sources can reap the same benefits as its natural counterpart. Lighting selection is often primarily dictated by its CRI (Colour rendering Index) and CCT (Correlated Colour Temperature). These represent the ability to accurately reproduce colours as seen under natural daylight.
However, there is no ‘one optimal selection’ that will suit every instance. In light of this, brands such as Philips Lighting have released a guide-lined document, ‘Designing people-centric hospitals using Philips lighting solutions,’ offering LED lighting solutions to this biological response to light.
For example, it is recommended that homogeneous, indirect light fixtures be placed along the sides of corridors rather than centrally in order to avoid patients being disoriented by being wheeled, face up, rhythmically passing under bright lights. This also aids in illuminating signs and directional indicators on walls. Generally, the use of direct lighting is often avoided as it gives an impression of being confined and may cause glare or overheating.
Patient rooms are where the majority of, if not all, the time is spent by those seeking treatment in healthcare centres. Here, confined to their beds, patients experience their surroundings from a different angled perspective than they are accustomed to. Because of this, it is vital that ceiling lighting is positioned with this in mind, as placement directly above beds can create glare and cause eye strain and headaches.
Philips has re-approached lighting design for patient rooms in accordance with research done connecting light and the regulation of sleep. This product is formatted to mimic the varying patterns of daylight in order to regulate patients’ biological clock. For functionality, this can also be overridden by staff to supply appropriate lighting for examinations. All of these considerations make this ideal for the functional, emotional and biological needs of both medical staff and patients. The use of this in patient rooms has resulted in:
1. Longer sleep duration
2. Shorter time taken for patients to fall asleep
3. Enhanced mood of patients, as derived from HADS (Hospital Anxiety and Depression Scale) depression scores.
Not only have these solutions improved patient wellness, but they are also capable of reducing energy consumption by up to 50% with LED lighting and up to 80% through lighting controls. It is this kind of collaborative thinking that can economically, sustainably, and architecturally transform the way we design healthcare.