Modern medical devices are very complex, they must show many different kind of information, from ordinary digital values to sophisticated graphical data. Medical devices have to do it in an understandable way to avoid dangerous mistakes. There are several different ways to present the information. The most appropriate is to use display, in this case the best choice would be the color graphical display. Such kind of display allows many different data to be presented clearly and makes possibilities to create an very intuitive user friendly interface, avoiding misinformation. In portable devices this kind of data presentation is great advantage but we need to take under consideration low power consumption. Additionally, in medical portable dev...