Employ color sensors to diagnose skin diseases

Color related skin conditions or alterations can be identified accurately using optical instruments. While in the past such skin color measurements were only possible in laboratories with expensive spectrometers or special measurement equipment, nowadays doctors can use handhelds based on multi-spectral color sensors. The demand for precise color measurement in both the area of analysis using instruments for medical diagnostics such as point-of-care (Po Ct) and in dermatological research and applications, and especially for diagnostic documentation, is constantly rising. For example, in pharmacology—skin conditions or changes as a result of disease or environmental influences can be determined and documented via optical measuring instruments.

The results of these measurements can be used both for evaluating skin diseases and for preparing treatment or assessing treatment success. Gray scale levels, colors and spectral data followed by a subsequent analysis, color and spectral algorithms as well as application-specific evaluation are the basis for a broad application of optical measurement methods in the field of diagnosis.

In the past, skin measurements could only be performed in laboratories with high-end and expensive spectrometers or special instruments. Nowadays it is possible to perform same or similar analysis applications, such as the measurement of solids or liquids based on multi-spectral color sensor technology. Thus the same performance is provided at much lower cost. Using a non-contact measuring system, skin diseases such as psoriasis and neurodermatitis can be assessed, based on the erythema degree and the skin type (taking erythema and melanin content into account) or skin redness can be determined during a patch/irritation test.

Sensor tasks are also found in spectral skin analysis with (skin) color management as recommendation and follow-up tools for prescribing medication. Multi-spectral sensors offer an excellent price/performance ratio for use in laboratory technical measurements or in "mini-laboratories" dedicated for example to evaluate test strips for clinical/chemical parameters such as glucose, ascorbic acid, keton bodies, protein, Ph values, blood, nitrite, leukocytes, bilirubin, and urobilinogen. Other possible fields of application include the spectral detection of medical and biomarkers such as in pregnancy tests, ovulation tests, diabetes, infectious diseases, and drug tests. Such spectral techniques can be used for microfluidic measurements to analyze fluid contents of medical or chemical cuvettes. In this method transmitted light reaches to a sensor while passing through the fluid contents. Spectral measurements are performed and based on a sample of reference water the spectral shift allows to determine various chemical contents and parameter within the measured sample. Using color sensors, a reference application can be built into a compact handheld measurement device for microfluids. This allows the convenient measurement and data transfer to evaluation systems.

Color measurement methods
Color measuring tasks are performed in different ways. Tristimulus sensors are compact and optimized for large numbers and fast measurement tasks. Using an RGB filter, they are ideal for color detection. True color sensors with XYZ filter are suitable for absolute color measurement based in the Cie 1931 standard for human eye perception. Both sensors work according to the colormetric principle.