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S.I.V.R.A.

Variable Lighting Systems with Automatic Regulation
 
The light and our organisme

In conjunction with the Lighting Research Center.
Our organism is regulated by means of light, insofar as it is affected by the intensity of light and the length of exposure as determined by the light-dark cycle (circadian rhythm). Following circadian rhythms guarantees a greater sense of well-being.
Light strikes the retina, and the latter transmits the corresponding signals to the brain by means of electrical impulses. In particular, these impulses reach the supra-chiasmatic nuclei and are transformed into electrochemical impulses directed to other areas of the hypothalamus, the pituitary gland and the pineal gland. The pineal gland then transforms these nerve stimuli into hormonal messages.
At night, some hormones (like melatonin) enter into circulation, while others (like hydrocortisone) drop to a minimum, and, as a result, body temperature falls, the heart beat slows, and blood pressure drops.

Bright artificial light
Bright artificial light, in excess of 2500 lx, blocks the production of melatonin. Consequently, it awakens the organism and increases body temperature, which influences, in turn, our efficiency – especially when performing tasks that require complex cognitive activity.
These effects, which are positive over the short run, can become a source of stress when prolonged.
Workers subjected to "bright" light during an entire shift undergo alterations in circadian rhythms, with a consequent decrease in attention and efficiency. Precisely for the purpose of attenuating problems inherent in working at night in environments with below normal stimulation levels, such as control rooms, we designed SIVRA, programming it to increase luminous stimulation by continuously varying color and the intensity of light emission.

Dynamic light
Dynamic light is a light that changes in terms of illuminance levels and color temperature over the course of the day or night, but not in a fortuitous manner. Rather, it does so based on scientifically predetermined programs.
During research in the United States at the Lighting Research Center at Rensselaer Polytechnic Institute in Troy, SIVRA, a program of light variation devised in Italy, was tested and also compared to three other lighting conditions, which were presumed to have different photobiological and psychological effects.
20 subjects underwent a series of tests using for 12 nights:
a. Low, constant light at 250 lx;
b. High, constant light at 2,800 lx;
c. Dynamic light with a minimum intensity of 200 lx and a maximum of 2,800 lx, which progressively increases.
d. Dynamic light with values ranging from 2,800 lx to 200 lx, which progressively decreases.
The results of the experiments run confirmed that the biological-dynamic light produced by SIVRA is capable of improving efficiency and wellbeing.
The diagram illustrates the effect produced by the four different lighting conditions on the "arousal" levels (emotive and perceptive status) of the subjects, which improve under conditions where the illuminance levels are decreasing and high.
An analysis of the sleep diaries showed that the subjects fell asleep at different times based on the characteristics of the light to which they were exposed. This made it possible to verify whether excessive nocturnal stimulation could delay the onset of sleepiness, which might not be desirable after a tiring shift like the nightshift. Excessive luminous stimulation, therefore, can be as counterproductive as below normal stimulation levels. The experimental results confirmed the initial hypotheses.
At the start of 1998, the Sivra light fixtures was included in the catalogue of products.
Additional informational material is available upon request.