London Hospital Fitted with Circadian Lighting System

St. Mary's Hospital has completed a full circadian lighting retrofit of its dementia care ward using LEDs from PhotonStar LED Group PLC.

Driven by demands from senior clinical staff to provide healthier lighting for elderly patients while reducing nursing costs and saving energy, the retrofit used the company's halcyon wireless lighting and control systems, including 56 high-output halcyonLIFE LED luminaires. The project was supported by National Health Services.

Circadian lighting mimics natural daylight and creates a simulated "biological darkness" at night by changing the color and spectrum automatically throughout a 24-hour period.

At night the light sources are spectrally modified and dimmed using microprocessor control, enabling them to deliver light with <15 melanopic lux, a measurement of light on nonvisual cells. This is a reduction of at least 50 percent compared to conventional low-energy compact fluorescent and LED hospital lighting.

This almost eliminates the risk of a response by the patient's intrinsically photosensitive retinal ganglion cells, instead creating what the body perceives as darkness and allowing the body to function as it should at night with healing, sleep and calm processes, lowering levels of cortisol, a stress hormone.

Natural light and dark cycles have numerous benefits, including 25 percent faster recovery times, enhanced immune response and reduced dementia symptoms, as well as 35 percent better cognitive processing speed, memory and concentration, according to PhotonStar.

The halcyon wireless control system reduced the necessary controls cost by 80 percent against a wired alternative and will achieve project payback in less than 38 months, the company said.

For more information, visit www.photonstarled.com.