I had the same experience with my capstone project. We were really confused on what class it would be considered. On the other hand we had so many different components, that we had to do research for each one separately. Our project was a medical device that was able to measure blood oxygen level, heart rate and blood glucose levels. Ultimately, most of these sensors are considered as class II. After looking on the FDA website realized that most of the sensors we had are all considered class II. Initially, we all ruled this a class I, because it did not seem like these sensor could be considered class II.