METHOD AND APPARATUS FOR DETERMINING CIRCADIAN INPUT
A method and apparatus for determining the circadian input of a light source includes selecting a circadian input to be measured based on an action spectrum corresponding to a wavelength sensitivity of photoreceptors for a circadian regulation system, where the circadian input is configured to stimulate a retinaldehyde photopigment, and for measuring spectral intensity across the action spectrum to determine the circadian input of the light source.
1 . A method, comprising:
selecting a circadian input based on an action spectrum, wherein the action spectrum corresponds to a wavelength sensitivity of photoreceptors for a circadian regulation system, wherein the circadian input is configured to stimulate a retinaldehyde photopigment; and
measuring spectral intensity across the action spectrum to determine the circadian input of a light source.
2 . The method of claim 1 , wherein the retinaldehyde photopigment comprises at least melanopsin.
3 . The method of claim 1 , wherein the circadian input is correlated with a depression of serum melatonin levels in a mammal.
4 . The method of claim 1 , wherein the circadian input has a peak intensity at an electromagnetic wavelength in the range of approximately 425 nanometers to approximately 505 nanometers.
5 . An apparatus, comprising:
means for selecting a circadian input based on an action spectrum, wherein the action spectrum corresponds to a wavelength sensitivity of photoreceptors for a circadian regulation system, wherein the selected circadian input is configured to stimulate a retinaldehyde photopigment; and
means for measuring spectral intensity across the action spectrum to determine the circadian input of a light source.
6 . The apparatus of claim 5 , wherein the retinaldehyde photopigment comprises at least melanopsin.
7 . The apparatus of claim 5 , wherein the circadian input is correlated with a depression of serum melatonin levels in a mammal.
8 . The apparatus of claim 5 , wherein the circadian input has a peak intensity at an electromagnetic wavelength in the range of approximately 425 nanometers to approximately 505 nanometers.