Imaging system with four different wavelengths obtained from LEDs

To evaluate skin pigmentation in different skin layers, there is special light adapter needed in order to take multispectral pictures of skin. As there are different optical properties of skin pigments,  4 different light sources have been chosen. blue λ= 470 nm – highly absorbed by epidermal melanin green λ= 576 nm – hemoglobin peak red  λ= 660nm – epidermal dermal boundary IR λ= 865 nm – low absorption, sensitive to scattering to measure papillary dermis thickness. There was lighting source for “Nikon Coolpix E3100” digital camera developed to take multispectral images of skin. Making adapter The drawing of  lighting adapter The lighting adapter isn’t very hard to build. You just need to make circular PCB and solder LEDs with protective resistors. The PCB image:

Skin reflectance spectra

According to earlier modeling description, there were skin reflectance spectra calculated for skin with most common properties: Melanin (volume fraction 2% in Epidermis); hemoglobin HbO2 and Hb (150 g Hb/liter ) and Thickness of collagen tissue in papillary dermis about 0.1mm.  

Skin Structure Diagram

Skin is very intelligent structure of our body. It is very elastic and pretty strong to protect inner tissue. It also acts as thermo regulator of our entire body protecting from overheats when we sweat and when there is cold – the blood flow is reduced to skin tissues to save heat to inner organs of body. Skin is pretty resistive to harmful chemicals, microorganisms and if dry it has high electrical receptivity. From biochemical side – skin can produce vitamin D when exposed to sunlight, which is essential for the growth and maintenance of our bones. The extensive network of nerves within the skin feeds information constantly to the brain concerning our surroundings. So it is full of sensors to know the external world like temperature, pressure. Don’t even let me start about skin importance in fashion industry. About how much there is attention paid to cosmetics, beauty shine. …

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About melanoma

Melanoma is one of the fastest spreading lesions. Melanoma is curable if it is diagnosed in early stages. If melanoma is diagnosed in early stages, the curability reaches about 90 percent of patients. In other hand if melanoma is diagnosed in late stages, then curability is less than 50 percent. In order to reach better curing result it is not enough to diagnose the disease, but there is permanent monitoring needed before ant after procedures. In this website you will find information about melanoma from technical side. Lets say, how lesions are dedicated, how photographed and what do doctors do to make a diagnose. There are many techniques of doing melanoma diagnoses. The most widely used by dermatologists is ABCD(E) rule, where skin images are taken and then shape, color and structure analysis of lesion is made. This rule is so simple, that everyone can do it by himself, bu …

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Interfacing MPXV5100 pressure sensor to Atmega8

The MPX5100 series piezoresistive transducer is a state-of-the-art monolithic silicon pressure sensor designed for a wide range of applications, but particularly it is convenient to interface to microcontroller or microprocessor with A/D inputs. This is thin-film metallization, and bipolar processing to provide an accurate, high level analog output signal that is proportional to the applied pressure. More details can be found here MPXV5100 This sensor measures differential pressure comparing to atmospheric so when there is no pressure applied it shows 0kPa;