I am not sure what "the semantics are only expressed in the form of textual description" means, but it certainly sounds wrong -- or at any rate sounds like a questionable assumption that will curtail possible answers to your question. For a more inclusive perspective, see for example:Book The Forms of Meaning: Modeling Systems Theory and Semiotic Analysis

I have a feeling that syntax factors heavily in how people interpret a sentence's semantics. I personally believe that a pure logical language doesn't work that well in expressing phenomena - i.e., how do you logically represent "red" without merely arbitrarily assigning a variable to it? I feel that where a logic best works is in methodologically leading, in practice, to some form of accurate reference of the phenomena.

I recommend for healthcare to look at ISO 13972 health informatics clinical information models. It gives a lot of guidance on context, knowledge, meta information, terminology and code bindings, and modelling.