In the coming years, many resources will be dedicated to the requalification of lighting systems in all places of public and private health services, from hospitals to clinics, from patient rooms to analysis laboratories. Major aims of this commitment will be greater functionality and energy efficiency as well as better working conditions for doctors and nurses in their daily activities. Proper lighting of the hospital rooms can make the stay of patients more comfortable and safer, stimulating the immune system.
TASKS AND REQUIREMENTS
Hospital patients should be able to manage the lighting in full autonomy from their bed. Some relevant tasks are the visual control of the therapeutic devices as well as having the emergency commands in view and at hand to request the prompt intervention of the nursing staff. Other basic needs to be considered are reading a book or looking at the screen of a tablet, computer, or TV without eyestrain. These activities require diversified light distributions. Generally, the supplied device is placed at the head of the bed (hence the name "bed head") and is equipped with a series of light sources provided with the respective optics. The "bed head" provides indirect lighting of the room, direct lighting and zonal or point lighting. Best models are equipped with high-efficiency LED sources that emit regulated luminous fluxes both in quantity and tone. Thanks to the double regulation, complete lighting flexibility is achieved. The adjustment of the light flux allows patients to adapt the light to their personal needs. Patients in old age and people who have suffered trauma or are suffering or debilitated, may have deficiencies or reductions in their normal vision. Hence the need to adjust the amount of light not only in the bed area but also in the entire room and in the bathroom.
COLOR TEMPERATURE AND QUANTITY OF LIGHT
Adjusting the colour temperature (shades of white light) is a performance offered by the most advanced LED technology luminaires called "tunable white" available today in various versions. A simple command allows to create a correspondence between the white point of the artificial lighting of the room and the daily and seasonal variations of the colour temperature. of natural light with beneficial effects on the patient's ability to respond to therapies. The high color temperature light of the central hours of the day (>4500 K) stimulates the production of hormones that help boost the immune system. The low colour temperature light in the evening (>2900 K) promotes relaxation and rest. For the daily work of the nurses and for the visits of the medical staff, a sufficient quantity of direct light on the patient's body is needed to make their activities easy, safe and effective. The reference standards (UNI EN 12464-1 "Lighting of workplaces. Part 1: Indoor workplaces") prescribe for normal visits the average maintained illuminance values of no less than 300 lux with Ra (Color Rendering Index) minimum equal to 80. It should be remembered that when using the denomination "average maintained illuminance" we mean the average lux value for a given surface respected, that is, never exceeded in defect, during the entire period of operation of the system. When carrying out therapeutic treatments, the average illuminance maintained must not be less than 1000 lux with a minimum Ra of 90. With these values, it is easy to understand the need of systems designed with multiple switching on and adjustable in the supply of the luminous flux.
ADDITIONAL LIGHT SOURCES
Generally, the head-bed device is not sufficient to provide illuminance at higher lux values and therefore additional light sources have to be installed near the bed. The most common solution consists of flush ceiling or recessed lights. The use of recessed light fixtures or systems in which the light sources are integrated into the ceilings or walls ensures the maintenance of the maximum hygiene conditions needed in the hospitals. The frequent cleaning and sanitizing operations of the lighting systems must not encounter obstacles or require additional work. This is the reason that leads to avoiding the installation of suspended or wall-mounted light fixtures. Integrated solutions that include LED modules placed in niches, grooves, slits, false ceilings, counter-walls, and cavities in flooring are also problematic. The presence of crevices or micro spaces makes it difficult to restore a perfect hygienic condition with the usual cleaning tools supplied, thus compromising the maintenance of an adequate level of healthiness of the environments. The selection of light fixtures to be installed must always take into account the specific needs of the rooms. For hospitals, clinics and surgeries, compact products are generally adopted, with a high degree of protection (IP54 or higher), equipped with transparent or semi-transparent screens to facilitate cleaning and guarantee maximum hygiene. Small dimensions allow these light sources to be installed in confined spaces, on low-height walls, recessed in false ceilings with cavities a few cm deep.
ATTENTION TO THE USER'S NEEDS
Basis of each lighting project and guideline to the choices of designers and installers should always be the attention to the needs of users of the health system. Entrance, information and reception areas, corridors and waiting rooms are to be treated as common and connecting spaces where the task of light is to indicate and communicate the services offered, to facilitate orientation, and to make the stay in health facilities safe, comfortable, and pleasant. The mentioned standards for lighting prescribe 200 lux as an average maintained value for waiting and reception rooms, 200 lux for corridors during the day and 50 lux at night. In the common areas of hospitals, the light must be designed to give people a clear and distinct vision of the services offered and to facilitate the work of operators in conditions of total safety. When entering a hospital, the distribution of light should be designed to facilitate orientation with a clearly visible graphic signalling system from a plurality of observation axes. Signalling with light means making the information relating to the various functions and activities present in the entire hospital structure perceptible from any position and distance. Similarly, orienting means marking with light the paths that start from the entrance and lead to the various departments, clinics or areas of the health unit. Well highlighted colours are a powerful tool for promoting orientation, making the space easily readable and easy to remember. Communicating with words, in fact, presupposes an ordinary ability in the use of vision that cannot be attributed to disabled people or people who have suffered trauma, or are in therapy or in a state of convalescence. Furthermore, light colour allows us to overcome the problem of the linguistic understanding of messages in a increasingly multi-ethnic society.
RESTING AND WAITING AREAS
Another function present in the common areas is that of resting and waiting. When spending a lot of time waiting in hospital halls or common areas, it is rare to find well-equipped spaces for this forced condition. Lighting is often lacking, disturbing and uncomfortable, while the quantity, distribution and chromatic quality of light should be the main goals of the hospital project, always taking into account the health conditions of people in "patient waiting". The most interesting and innovative solutions, based on the use of advanced products in the lighting sector take into due consideration the needs of people and provide localized light customization systems in the waiting areas.
LIGHT ISLANDS COULD HELP
For safety reasons, there is a tendency to standardize the lighting along all the connecting spaces of the hospital or clinic complex. In this way, however, each path is similar to the other. The general effect is of a widespread visual monotony. Sometimes it is difficult to perceive the distances to be covered or to recognize the area that is looming at the end of a long walkway. This does not help to easily identify the various areas of the hospital. While ensuring the vision of every possible obstacle to walking, it is advisable to vary the lighting by creating more or less bright areas. It is advisable to design some kind of "light islands" along the network of connections, in the points where two or more paths converge, in the area of access to the lifts or stairs, in correspondence with the entrances to the hospital rooms or other services. The gradual variation of the lighting makes the so-called "connective" spaces livelier and stimulating, more similar to the domestic environment which, in all areas dedicated to welcoming, hospitality and care, always remains the main implied reference in the user's psychology.