Measurement Guide

1. Know your impurities/skin porphyrin

Porphyrins are by-products produced by sebum residue and bacteria, especially Cutibacterium acnes (the bacteria linked to acne) that live in clogged pore and hair follicles on the skin. Due to increased sensitivity to sunlight and inflammations caused by bacteria porphyrins, a person with excessive skin porphyrin may experience:

• Acnes and other inflammatory skin diseases.
• More pimples, whiteheads, or blackheads appear.
• The skin may look greasy, especially on the nose, forehead, and chin (T-zone).
• Pores may look bigger or darker.

To assist diagnosis of impurities caused by skin porphyrin, up to 5 images can be taken under the UVL light using the ChoiceTech Skin Analyzer. Our algorithm then evaluates the impurities in each image and combines the individual results to provide a final grading. To be specific, in each image we study the color intensity of porphyrins and classify them as red and blue, where:

• Red represents inflammatory porphyrins
• Blue is for other non-inflammatory porphyrins

Table. 1 Representative images of impurities detection and classification

Captured Image	Analyzed Image

2. ChoiceTech skin impurities grade

The following ChoiceTech impurities grade has been co-developed by ChoiceTech and dermatology experts. For each image, we detect impurities to provide a quantified Result score. The final score for impurities is computed as the Average of all result scores, and based on the scale shown in Table 1, we grade skin impurities into clear, almost clear, mild, moderate, and severe. Also presented is an Average Per Age Group score to help understand how the skin impurities condition compares with peers.

Table 3. Representative images of skin impurities grade

Clear