Lighting design and illumination options
 

If you use lighting system improperly, it is easy to make bacteria, dust accumulated. However, excessive luxury, high-intensity lighting system that exceed the standard lighting will greatly increase investment in hospital construction and will also increase maintenance costs, is not good to save energy. China set down lighting illumination value of medical standard-setting earlier, currently, "Architectural Lighting Design Standards" GB50034-2004 in the proposed hospital building illumination value is more appropriate (see table below)

Illumination value table
　　
Different place illumination data (lx)

Ward, stairs, corridors, toilets

Lobby, waiting room, on-duty room

Consulting room, treatment, nursing stations, intensive care unit, office, control room
　　
Labouratory, laboratories, pharmacies

Emergency room, operating room

According to the various departments of different hospitals with a variety of lighting design options for the design process, there are many different ideas, the following of a few typical place for some discussion.

Hall lighting ( Second class)
Public Hall is the central zone where most people come and go. It is connected with the clinics, the corridors and stairways. If the lighting of the public hall is the atrium, the gas discharge lamps shoud be used. The smooth conversion of natural light and artificial lighting should be dealt with well. It is shoud be avoid that the illumination in the corridors around is too low, the gap between bright and dark is too large to cause visual discomfort. The convenience of repair and maintenance must be considered for the lighting in the public hall where has less natural light.

The small Floodlights should be installed on the wall, so that the maintenance staff can reach the lamps, and it is convenient for maintenance. The inside and outside of the services window should be bright, because the medical staff and patient or family need to check the documents and costs.
 

Public corridor lighting
The public corridor in the emergency medical building is the major crossings indoor. There are clinic rooms both sides, and there is one one door between the corridor and the clinic room. The illumination in the clinic room is more than 300lux. If the illumination in the corridor is too low, people will feel unconfortable with the lighting change between the clinic room and the corridor. Therefore, we must consider all these factors during designing.
 

The illumination of the corridor sould refer to the illumination of the clinic room and the hall, it should be equivalent or 30% higher, normally 100lux. The corridor is mainly relied on artificial lighting, Commonly we use the lamps, which can prevent the glare, installed on the ceiling of the corridor. If the requirements are higher, we can use reflective ceiling, which is better. Sick patients lying on the bed will not be discomfort for bulbs or tubes.

The public corridor in the ward is different from the emergency medical building. Patients need quiet environment, so we must use even and soft lighting. Therefore, the illumination is lower, normally 50lux or so. The lamps with warm white or small fluorescent should be installed. The door bottom of every sickroom must have a footlight for nurse inspection during night. So the general lighting can be turned off during night.

The emergency lighting and evacuation lights in the corridor and emergency gate must be perfected. The duration of the emergency lighting must be improved. Because when emergencies happen, it is slow for patients to evacuate, and some of the patients needs stretchers. It will cause very serious consequences without lighting. The safe passages of corridors, the top of the doors to outside and safety stairs must be installed with the lights with the words Safety Exit. On the corner of the long corridor must have evacuation lights, and the gap between two evacuation lights must equivalent to 20m or less. It is suggested that the nickel-cadmium battery emergency light are replaced with EPS. EPS are much better considering the lifetime, investment, maintenance, reliability.



Sickroom lighting
The sickroom lighting can be divided into general lighting, local lighting and emergency lighting.

Regarding to the general lighting in the sickroom, we must consider the requirements of the patients and the medical staff, for creating a quiet and warm environment. According to the regulations of the Architectural Lighting Design Standards GB50034－2004, the illumination standard in the sickroom is 100lux. The colour temperature should be less 3300K. the low colour temperature fluorescents are generally used.
 

Some of the patients needs lying on the bed for long time, if we use the ordinary lamps, it will cause dazzling and disconfort. It is the best to use diffused lighting lamps or reflective lighting. For the sickroom with two or three beds, we can use fluorescents. In order to avoid dazzling, the reflective lighting can be used, good result, but high investment and high operation cost. It can be used in the high-grade sickroom.

The local lighting in the sickroom is mainly for providing lighting for patients` reading and medical staff working. Generally, the module type fluorescent lamp can be installed, or wall lamp whose arm can be adjusted. The dimmable lighting should be used, which can meet the requirement of the local beds, but not influencing others.

The ward area must be designed having night lighting  to meet the requirements of the nurse in night shift and the patients. The night footlights can be installed near the bathrooms or near the door, the corridor. The position of the footlights must avoid the direct light to the patient's eyes.

The nurse station has the requirements of precision operation, writing and reading. So it needs high illumination. According to the “Architectural Lighting Design Standards” GB50034－2004. the illumination of the nurse station should be more than 300lux, and uses high colour temperature lamps.
 

The lighting of treatment room
The treatment room is the main function room in the emergency building. Generally, it is located in the position with better lighting in the building. The natural lighting can be taken full advantage of. Considering the cloudy, rainy weather and the night lighting, the treatment room needs high illumination. Because the doctor must look at the minor changes about the face, eyes,ears,nose and throat and other parts of the patients clearly, as well as numbers of sphygmomanometer, thermometer. Besides, the doctor must take notes about medical records, make prescriptions and laboratory test and so on. So the horizontal and vertical lighting in the treatment room must meet the requirements. The illumination should be more than 300lux. The treatment room with good natural lighting can uses venetian blind. The interior decoration should avoid direct sunlight to damage the important equipment.

The treatment room uses cool temperature lighting. The colour rendering index should be equivalent to 80 or more, for concentration and attention. Besides, considering the patients may lying on the beds, the design of the lighting should avoid causing dazzling for the patiients. Therefore, we should use reflective thin straight tube fluorescent lamps with visors.
 

The lighting of operating room
Take the clean surgery room for an example: Surgical local lighting uses Operation shadowless lamp which must meet the requirements of clean laminar flow. The operation shadowless lamp with claw type structure can be choosen. The general lighting uses clean light installed into the ceilling. One of the lamps should meet the requirements of emergency. The film viewer can be installed into the wall. The UV germicidal lamp can not be installed in the clean surgery room. The power sockets can be installed on the walls and the integrated gas tower crane. Besides, the door of every operating room must installed indicator lighting “on operation” to prevent unrelated persons going into the room.
 

The lighting of the large medical equipment room
Before, the design of the lighting in the medical laboratory would consider that the fluorescents influence the medical equipment, so normally, the direct current or filament lamp would be used. But now, according the reseach about the medical equipment manufacturer and the equipment use environment, many equipment have strong anti-interference ability. Some of the small medical equipment (such as electrocardiograph, electroencephalograph, medical ultrasound and so on), they do not have special lighting requirement. The lighting of the electrocardiograph and electroencephalograph is 150lux or so. The electroencephalograph and medical ultrasound need lighting dimmers. Because the medical ultrasound almost works under the state of semi-dark room. But for MRI Room, which needs EM shielded, it still uses direct current. Therefore, the illumination can not be increased. The design of the lighting should be based on the requirements of the equipment.
 

Illumination is usually required 100 ~ 150lx or even lower for many medical devices. But in order to maintain and repair interventional procedures or treatment, sometimes is still more than 300lx . Therefore, an ideal setting in the control room in addition to general lighting s another set up another dimming device to meet different needs. Specific design requirements should be based on different equipment needs. Such as CT, linear accelerator have different illumination demanding, but maintenance of these large expensive equipment needed relatively high illumination, it generally takes 250lx above, usually can be used to adjust light levels, maintenance and use fluorescent lamps to  reach 250lx.

Each medical technology equipment room in the public walkway should be installed  "working Do not enty" warning light above the door. Warning lights should be linked with the medical technology equipment, that medical technology devices (such as X-ray machine) to start preparation work, warning lights, to prevent access to the unnecessary harm.
　　
UV lamp configuration

Using UV light is effective method to kill airborne bacteria in hospital, but it has the strong UV impede for eye health, so the set should try to avoid direct exposure to ultraviolet or medical staff the patient's field of vision. Therefore, the case should be no one used ultraviolet light disinfection in the room.

　
According to "civil electrical design specifications," the provisions of infectious diseases department of the emergency door, waiting room, infectious diseases rooms, clinics and latrines, and contaminated areas of the walkways and other places should be set UV light. The loop power control should be concentrated in the nurses station, selected by the medical staff at the right time for UV disinfection, UV lamp switches’s design shoud be a clear identity to different from ordinary light switches.
　　
Number of UV light by the following formula:

There are general health requirements, N = 4P2 / H. V. F
 

A high degree of sterilization requirements, N = 0.05v / H. F
 

Formula, N-number of UV lamps (at 30W / sticks);
 

P-number of indoor people ;
 

H-germicidal lamp to device distance (m);
 

V-room volume (m);
 

F-light efficiency (0.8 ).
 

Practical engineering design can often be simplified formula to estimate the above, if the general health requirements, it would be within 15 to 20 square meters to set a lamp on a high degree of sterilization, the number can be doubled (eg, infectious diseases rooms, contaminated toilet and walkways).