It sounds like you'd want a related table for vital signs. One field would be the patient ID, which you'd use to link the vital signs records to the patient. Another field would be the type of entry, e.g. blood pressure. You'd want a timestamp, etc.
Make sense? One record in the related table for each chart entry.
That's exactly it! Thanks!! How do I set up a relational database though?
Okay... I've figured out the relational database thing for my vital signs, but how do I set that up so the user can keep entering as many sets of vitals as they want (in layout mode)? Is there a way to set a button to keep adding a new set of vital signs within a single record??
Use a Portal for this. With the correct options selected, you'll be able to log each new measurement simply by finding the patient's record and logging entering the data in the next blank line of the Portal.
Look up Portal in Filemaker's Help system and you'll find a pretty decent description of how to set this up.
You should create, on your patient layout, a portal showing related vital signs.
In the relationship graph, in the options for the relationship (double-click the equal sign), on the Vital Signs side, select the checkbox for "Allow creation of records." That will enable you to add vital signs by clicking in the next empty row of the portal.
By the way, this is not about data arrays. :)