Before starting to think about the concrete program, you must understand the problem domain first.
The description you give is only a snippet of your whole assignment, it seems.
E.g. several terms are unclear:
a) what are "vital sign" data?
b) whati meant by "as shown above"?
c) what are "group of data"?
d) what is a "diagnostic session"?
e) what is a "patient simulator"?
...
z) how are these terms interrelated?
Draw on a sheet of paper the whole system:
- what components are involved (simulator, PC, Data exchange, programs that run on each device, etc.)
- write some use cases how actions are triggered and what the output is from such triggers
- draw the sequence of actions that happened with such a trigger of a use case
- ...
Identify what your task is in that whole system:
- write a program to fire up a Dialog window that asks the user to enter some file path to process
- the file consists of one or more diagnostics session data(?)
- one diagnositcs data consists of groups of data(?)
- a group of data consists of a sequence of data samples(?)
- a data sample represents a time slice of the diagnostics session(?)
- the output of running the program is ...?
Now you are ready to think about drafting a concept on how you want to process the data.
The Dialog is what you show in you sample code (this is the zero-effort task).
now you must add the real function to the program:
- trigger reading the file
- process the data - not clear from your question
- write the output - not clear from your question
- to a database?
- to the User Interface?
- to some file?
- filtered?
- sorted?
- ...?
Once all this above is clarified, you may start to think about programming, but first. what is your eco system you work on:
- What is your development environment (PC, VS2010, C#, ...)?
- What is the productive environment for the completed and shipped program (Windows PC, collaboration with program X, Y, Z, ...)?
If you reached this point, get acquainted with the development environment and the language you want to implement the program (C# in this case).
Document your analysis.
Implement the data classes.
Implement the parser.
Test the parser and the storage of the data in the data classes.
Document this part.
Implement the data processing functions.
Test these functions.
Document this part.
Implement the the data output.
Test it.
Document this part.
Integrate all into the program skeleton from your question.
Test it.
Document this part.
Document your results.
Provide user documentation.
Ship it.
Cheers
Andi