Removing 60Hz from ECG using digital band stop filter

Let’s make a filter, which filters off the 60Hz frequency from ECG signal. As we know American power supply is 60Hz. This is common noise in biomedical signals, while they are powered from industrial power supply. This type of noise can be defined easily and can be filtered as parameters of noise are known. Here is one example of how to implement FIR filter using mathematical tools, like Matlab. This can be done by using microcontroller, like ARM or even ARM, because the frequencies are up to 1 KHz. Initial conditions: f0=60Hz – pover supply frequency; fs=500Hz – sampling rate; frequencies who define complex zeros: we get w0=0.754; Positions of complex zeros: Zeros and poles in z plane System Function From it we can calculate filter coefficients: And filter coefficients:         Also we know that: And here we get filter characteristics: We have band stop filter at 60Hz and…

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Imaging system with four different wavelengths obtained from LEDs

In order to evaluate skin pigmentation in different skin layers, there is a special light adapter needed to take multispectral pictures of skin. As there are different optical properties of skin pigments, four 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 need to make a circular PCB and solder LEDs with protective resistors. The PCB image:

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Histological Skin Structure Diagram

Skin is a brilliant structure of our body. It is very elastic and pretty strong to protect internal tissue. It also acts as thermoregulator 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 the 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 continuously 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 the fashion industry. About how much there is attention paid to cosmetics, beauty…

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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 the early stages, the curability reaches about 90 percent of patients. In another hand, if melanoma is diagnosed in late stages, then curability is less than 50 percent. To attain better curing result it is not enough to diagnose the disease, but there is permanent monitoring needed before and after procedures. In this website, you will find information about melanoma from the technical side. Let us say, how lesions are dedicated, how photographed and what do doctors do to make a diagnose. There are many techniques for making melanoma diagnoses. The most widely used by dermatologists is the 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…

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