US Patent 10188192 Apparatus and methods for modifying keratinous surfaces

An apparatus for treating human skin that has an applicator head having one or more applicator nozzles which may be in a array. The apparatus further has a reservoir comprising a treatment composition, a sensor, and a CPU. The sensor takes an image of at least 10 μm2 of skin, the CPU analyzes the image to calculate one or more localized L values of individual pixels or group of pixels of the skin. Then the CPU compares the local L value to a predetermined background L value to identify skin deviations. A skin deviation occurs where the difference between the background L value and the local L value is greater than a predetermined ΔLS value.