A concept is effectively a mental image. These mental images make up the building blocks of thoughts and ideas. Here's where it gets interesting. Concepts are also defined by all of their actual or potential instances, where instances are basically moments where this concept becomes familiar to us.
Instances help us turn this.
And this.
Into this.
By creating concepts we as humans have been able to develop complex notions and systems around things by communicating our concepts to others – without which we would have a very difficult time trying to communicate about the lion above. Concepts are also hierarchical:
Higher levels of which are termed "superordinate" and lower levels termed "subordinate". Additionally, there is the "basic" or "middle" level at which people will most readily categorize a concept. For example, a basic-level concept would be "chair", with its superordinate, "furniture", and its subordinate, "easy chair". (source: Wikipedia)
For this reason, analogies become a powerful tool to consider when developing your prototypes as many of the stakeholders you will need to communicate your concepts to will not come from a medical or scientific background. For example, instead of 'enhanced therapies for bradycardia' you might consider 'new treatment methods for people with slow heartbeats'.
To the large majority of individuals you may not need to effectively communicate the scientific specifics of how your product or service works, but you will almost certainly need to communicate your concept in an understandable way.
All of the prototyping that we did as part of the first bootcamp can be thought of as creating instances of your concepts. We want your team to understand your concept and the system in which it operates better than anyone - so building prototypes help us to create a common understanding, one which you'll later share with the outside world. Every instance [read prototype] you create brings you closer to a well defined concept.
By working on your concepts through rapid prototyping your mental image becomes clearer, and clearer, and clearer. We may not see the full impact of your concept until it has been out in the for some time. It may even have unintended consequences...