EMR Data Definition

[don_openhealth]

Hello,

I am developing an EMR system and would like
to know if there is a data definition for an EMR
(preferably a relational schema) that has been defined 
or is recommended by one of the standards
organizations (e.g. HL7, ANSI).

Anyone know of any and if so, do you have
any pointers to where they might be on
the web?

Thanks in advance,
Don