Each year a vast sum of money is spent worldwide to produce various types of systems or devices for use in healthcare. For example, in 1997 the world market for medical devices was estimated to be around $120 billion [1]. The history of the use of medical devices may be traced back to the ancient Egyptians and Etruscans who used dental devices [2]. Today, a modern hospital uses more than 5000 types of medical devices, ranging from a complex pacemaker to a simple tongue depressor [3].