Ingeniero En Informática

OpenEMR System Architecture

1. Revision History

2007-06-20 Original document by Rod Roark (http://www.sunsetsystems.com/)
2007-07-10 Minor updates for the new claims table and "effective dates" in insurance_data.
2007-08-02 Updated with "restoreSession" notes (section 11) and FreeB replacement info.

2. Introduction

This is a compilation of notes that will be of interest todevelopers who wish to become involved with OpenEMR, or to users who are interested in technical aspects of the project. Creation of this document was generously sponsored by Sam Rajan.

3. Other Resources

The Documentation directory of the OpenEMR distribution contains some earlier notes, technical and otherwise:

3rd_Party_Form_API.txt describes the interface as originally designed forencounter forms.
Database.pdf has some information about the original database design but is now obsolete.
FAQ is also quite old and doesn't cover much.
Functions.pdf describes interfaces implemented by some modules in the library directory, and is a bit dated.
HISTORY.txt is a brief summary of OpenEMR versions thru about 2002.
instruction-manual-032205.pdf is a valiant effort at user documentationfrom 2005.
modifications.txt is a brief list of the modules that must change in order to add data items to patient demographics.
NoIP.txt is an obsolete list of broken links.
OpenEMR_Backend_Spec.txt is another obsolete description of some interfaces implemented in the library directory.
OpenEMR-Win2003-server-install-new.html briefly discusses installation of OpenEMR on Windows 2003.Package.txt has some old notes about creating an OpenEMR distribution release.
README.phpgacl discusses installation of phpGACL for OpenEMR access control.
Readme.txt seems to be mostly a disclaimer regarding HIPAA compliance.
User_Documentation.pdf is obsolete and incomplete.
UserManualHTML-multiplepage is a good documentation effort from 2005. UserManualHTML-singlepage is the same thing in oneHTML page.

The accounting directory contains:

README.sql-ledger which describes setup of SQL-Ledger with OpenEMR.

The root of the distribution contains:

Changelog which is not very current.
INSTALL which is general installation instructions for OpenEMR.

Then there's http://www.oemr.org/ which is the home page for the project. It includes a manual, demo site, forums and adocumentation wiki. Of special interest to developers and others who install OpenEMR is the "FreeB Howto" at http://www.oemr.org/modules/wiwimod/index.php?page=FreebInstall&back=FreebInstallHowtos .

And finally, there's a fairly complete user manual in the form of a collection of screenshots with narratives at http://www.sunsetsystems.com/node/8 .

4. Database

OpenEMR installs many databasetables. Following is a list, with brief descriptions:

addresses - Contains street addresses for two other tables: insurance_companies and pharmacies. So it is effectively an extension of those tables. This is inconsistent in that some other tables (e.g. facility, patient_data, users) have their addresses embedded. The "foreign_id" column equals the "id" of the foreign table, but curiously theaddresses table does not identify the foreign table itself.

array - I don't see anything that uses this.

batchcom - Records messages sent to groups of patients using the "Batch Communication Tool".

billing - Billing items. Contains a row for every CPT4 code, HCPCS code, and ICD9 code recorded into an encounter. In addition has a row for each co-pay entered. The billing process alsomaintains state information in this table.

categories - Defines the tree of document category types. These are the category names that you see when viewing patient documents. Note that the "parent" column is a reference to the "id" column of the same table, thus the tree structure.

categories_seq - Holds the value of the last-used "id" for the categories table.

categories_to_documents -...