The theme on the 4th semester was "Collection, processing and presentation of biological signals". A part of the curricular on this semester was to work with a microprocessor. In the group I was a member of we chose to make ECG-system. Through interviews with the staff at the Cardiological department at Aalborg hospital we got input to the specification of requirements. We used structured program development (SPU) to develop the ECG system, which was programed in C.
We had some analog electronics before the microcontroller, just to do some gentle filtering and some amplification. The input signal to the microcontroller where first AD converted, and then sent through the microcontroller to a computer. But we also wanted the microcontroller to work as a stand-alone device, so we did some signal processing in order to calculate the e.g the heart rate. We attached a display to the microcontroller which could show the heart rate, and alarms in case of e.g bradycardi. The display could also give input to the microcontroller about the limits for bradycardi. Well you can read more about it here (Sorry only in danish)