Research On Evaluation Method For Biological Effect Of Lighting

The discovery of the third type of photoreceptor cells makes lighting extended from the visual function to the non-visual biological effects.The evaluation of the lighting quality also from the original single visual effects evaluation extended to the current visual effects and non-visual biological effects of double evaluation.CIE photometric system can better evaluate the visual function of the lighting system,but can't evaluate the non-visual biological effects of lighting,light biological effects of quantitative evaluation system has not yet been unified.In addition,with the deepening of research in recent years,some light quantities related to non-visual are proposed,and then it caused the term inconsistent problems,so it is necessary to use a standard way to describe the light source.LED,a new type of solid state light source,has bigger advantages compared to the traditional light sources,has been widely used in indoor lighting,road lighting and consumer electronics and other fields.So,it is very important to study the impacts of LED light on human non-visual biological effects.This paper is divided into two parts.The first part is to study the evaluation method of photobiological effects.A biological rhythm factor model M considering the ocular transmittances of different ages?pupil diameter and the illuminated area in the retina is proposed from the perspective of light conversion to quantitative evaluate the photobiological effects of light on different age groups.In experiment,young people and the elderly two different age groups are participated in the pupillary light reflex test in different lighting environment with three kinds of LED light with different color temperatures.The results show that the rate of change of systolic blood pressure and heart rate in young people is higher than that of the elderly under the same light condition.The rate of change of these two parameters is consistent with the theoretical analysis of rhythm factor change with age.This study can provide a basis for evaluating the actual effect of light environment on people of different ages,and provide a basis for designing more suitable healthy living environment for different people.The second part is to study the equivalent illuminance to describe the method of light source.Using this concept to analysis six kinds of LED light sources,and the physiological parameters were monitored under the six kinds of light sources,and then combined with the theoretical calculated rhythmic factors to evaluate the non-visual biological effects of light on the human body.The results show that the higher the equivalent illuminance value corresponding to the third type of photoreceptor cells,the higher the corresponding light source can produce stronger stimulus.The correlation coefficient between heart rate change rate and rhythm factor is more than 0.77,and the correlation coefficient between systolic blood pressure rate and rhythm factor is more than 0.86,both of which have a good correlation.Therefore,the rate of change of heart rate and systolic blood pressure can be combined with the biological rhythm factor to reflect the strength of non-visual biological effects of light source.