Philips and Maastricht University study lighting impact on cardiac patients

Nov. 30, 2011
Maastricht University Medical Center finds that cardiac patients sleep longer when hospital rooms feature lighting that emulates the day-night cycle using LED and other sources.

Philips has developed a hospital-room lighting system called HealWell that uses a combination of LED and fluorescent sources and networked control to emulate the natural day-night outdoor lighting cycle. The Netherlands-based Maastricht University Medical Center+ (Maastricht UMC+) tested the system on cardiac patients and found that patients in the HealWell-lit rooms slept 8% longer than patients in standard rooms.

HealWell utilizes LED-based solid-state lighting (SSL) for comforting blue-tinted cove lighting, near the ceiling, opposite the patient bed, SSL accent lighting focused on the wall opposite the bed, and dimmable SSL reading lights. The system uses a tunable fluorescent fixture in the ceiling above the bed that provides illumination for examinations and ambient light levels that vary in color temperature and intensity over the course of the day. Hospital staff has complete remote control of the lighting system and the patient can control the individual SSL sources.

The Maastricht UMC+ conducted the HealWell trial over a nine-month period studying the impact on patient sleep and well being. More than 100 cardiac patients were studied with tha group split between traditional and HealWell-lit rooms.

Maastricht UMC+ trial results

The medical center concluded that it couldn't make clinical claims of a healing effect attributable to the light, but that results were encouraging. "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," said Dr Petra Kuijpers, cardiologist at the Maastricht UMC+. "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."

Specifically, the study revealed that the HealWell system reduced the time it takes a patient to fall asleep by 30% over the course of the first to seventh night stay in the room. The result is patients sleeping 30 minutes longer per night on average.

Ironically LED and fluorescent lighting are often blamed for disrupting the human circadian rhythm, but it's increasingly evident that tunable light sources such as LEDs can improve health. 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."

Still the impact of lighting requires further study. "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," said Kuijpers of the Maastricht UMC+. "This is, however, an area in which further research is required."

Philips is already cooperating in additional trials. "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," said Philips' Schlangen. "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."