Understanding how light interacts with skin, can assist in designing physics based dermatological image processing. The key is to understand how light interacts with skin tissue. Skin consists of different layers with different spectral properties.
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.…
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…
Sometimes you might like to manipulate the members of C structures in more generalized way. This can be done by using pointer reference to structure. Normally it is easier to pass pointer to structure than passing entire structure to function. Structure pointer can be declared very easily: struct structure_tag_name *variable; For instance: struct position{ int x; int y; }pos1, *pos2; we can assign first structure address to structure pointer like this: pos2=&pos1; now we can access first structure members by using structure pointer: pos2->x=10; or we can write (*pos2).x=10; Structures can contain member pointers to other structures or to structures of same type. This way we can create lists – dynamic structure: struct list{ int listNo; struct list *next; //pointer to another structure }item1, item2; This way you can assign the pointer with address to another structure: item1.next=&item2; Read more about dynamic structures in C tutorials on internet.
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;
There aremany situations when you might need to measure temperatures or trigger some events due to temperature changes. It is very convenient to have these values in a digital format. Then you can transfer digital values to microcontroller to process data or jus to display on LCD screen. AD7416 Sensor description This is 10 bit digital temperature sensor which ca measure temperatures in range interval -40 to 125ï‚°C). Temperature conversion ADC has 15 conversion times. Sensor can be supplied from 2.7 to 5.5V, so it is no problem to connect directly to ARM microcontrollers. Data is transferred through I2C serial interface. More detailed description – datasheet can be downloaded from Analog devices page: AD7416. Here you find simple routine where Atmega8 microcontroller reads sensor data decodes temperature value and displays it on 2×16 LCD display. Lets connect everything to simple circuit. Don’t forget to connect pull-Ups to SCl and SDA…
AVRISP is very popular Parallel port programmer for flashing AVR type microcontrollers. Earlier I used programmer connected to com port, but frequently I needed this port for other purposes, I decided to make it work on parallel port. The programmer on parallel port is much simpler than connected to serial port, because there is no needed voltage adapter like MAX232. You can only connect your MCU directly to port. But for safety reasons there is good practice to use buffer ship like 74HC244. The header for programmer I used standard 6 pin ISP header. I wanted to make compact programmer, so I put circuit inside LPT head. Few pictures of it: Programming is usually done by using PonyProg software. Bellow is its configuration:
