Real-Time Plotting of Biomedical Signals in Applications Utilizing Windows Presentation Foundation Technology

Abstract

Utilization of personal computers in medicine requires strong emphasis on software performance. Contemporary programming languages give engineers great flexibility in developing applications. Since these technologies are more and more complex, there is a need to analyze methods of achieving desired results taking into account time requirements. This paper focuses mainly on development of plotting module using Windows Presentation Foundation library, which is one of the newest tool for software developers. Aspects of plotter creation for technologically limited screen are covered and conclusions are summarized giving recommendations regarding the topic. General methods of drawing signal on a raster surface are also discussed. Since medical signals in monitoring range consist of frequencies up to about 100 Hz, one has to take into account aspects of signal scaling in order to not to make its important parts invisible. The main problem is that personal computer screen, e.g. a monitor, is purely digital in nature; actually it is the set of pixels (consisting of three components). Because resolution is limited, the signal must be limited in frequency to the range which can be shown at a given plotting speed. This paper describes these aspects of signal plotting as well as the method for virtually increasing pixel resolution by using particular components of a pixel. This paper is a summary giving a general idea of the capabilities of the above mentioned WPF technology and the basis for creating such programs using methods such as: WriteableBitmap method, DrawingVisual method, Canvas Method type 1, Canvas Method type 2.