[Gnumed-devel] Gnumed structure and philosophy

[Tony Lembke]

> > Sure, in Horst-space. The very same (as in "the same physical
> > lines of") code is used in Richard space.

Jim's 'request for clarification' have been very useful in the past. So 
adopting 'Busser mode',  may I ask if I have an accurate understanding 
of the basic gnumed 'space' - its structure, philosophy and goals (for 
?gnumed 2.0) The snippet below represents my understanding of the 
gnumed concept as it has grown from the ideas of Horst, Karsten, Ian 
and others, and is not (of course) my original thought . (apart from 
the currently fictional term gnumedscript and fictional examples of 
code) This outline now may be completely off the track. I welcome 
corrections / admonishments. The corollary of this philosophy is that 
it is not necessary to determine the exact details of Richard space or 
Horst space as, given the right tools, we will all be able to create 
our own space.
                                           <========>

Although Gnumed will be an excellent, open-source replacement for the 
current crop of medical database packages, it will be significantly 
more than this.
Gnumed is a complete environment for designing medical packages.
Its multi-levelled stucture ensues the stability and integrity of the 
underlying EHR,  while allowing end-users the flexibility to customise 
both the functionality and the 'look and feel' of the application. The 
structure also increases the scope of the application by allowing 
interested 'scriptors' to write their own plug-in modules.

Level 1) SQL
 the basic tables of information are stored in an SQL compliant 
database. Postgres is the current 'database of choice'.
Written by - Core team
Estimated Current Level of completedness  v0.8

Level 2) The 'backend' EHR, (table information managed as views)
The tables are accessed through a  set of views that present the highly 
normalised tables in a more familiar structure. A set of methods allow 
safe access to the tables.
eg
    patientID.setDemographic(firstname=>'Tony')
    encounterID.setSOAP(assessment=>'Penetrating injury to leg')
    druglist=patientID.getDrugs(current)
Written by - Core team in Python
Estimated Current Level of completedness  v0.6


Level 3) Basic structural functions
Log-in, error tracking, log,  etc
Written by - Core team in Python
Estimated Current Level of completedness  v0.9

Level 4) Interface widgets
GUI elements that where necessary  utilise the Level 2 methods to read 
and modify the EHR backend
eg Scroll Wheel, Search boxes, drug selectors, dialog box
Written (currently) to utilise wxPython, but available to 'Level 5 
scriptors' as simple commands such as
     scrollwheel(prescribeDrug)
     scrollwheel(orderPathology)
     chart(test=>'hbA1c',startdate=>'10/2/2002',enddate=>'today')
Written by - Core Group in Python
Level of Completeness 0.7

Level 5) Modules
Modules are plugins elements that are added to a gnumed screen.
eg Prescription writing module, BMI module, scrapbook module, 
prescribing module, pastHx display
Modules can be written using 'gnumedscript', which allows the module 
developer to place interface widget elements within a layout and 
thereby interact with the backend EHR. The fonts/colours etc used by 
modules are determined by a 'style sheet' or skin and are not hard 
coded.
eg Module BMI
newModule('BMI"){
        structure{
                text(value="Height",style="label")." 
"input(size=4,name='Height'). \
                text(value="Weight',style="label")." 
"input(size=4,name='Weight'). \
                input(type=button,label='Calculate',onClick='calculateBMI()' \
                text(value='',style="strong",name='BMI_result', 
decimalplaces='4')\
        }
        function calculateBMI{
                BMI=Weight/(HeightXHeight);
                setText(BMI-result);
        }
}
Modules are wriiten in gnumedscript and can be written by anyone with 
basic scripting knowledge. Perhaps one day a GUI will make this easier.
Level of completeness
  -  Some modules functional
  -   gnumedscript 0.1

Level 6) User Interface
Endusers can design their own screens by determining which modules they 
would like to place where . They can also select or design their own 
'skins' to change the look of their application.
Written by all users as part of gnumed application.
Level of Completeness 0.4



Thus gnumed provides the blocks for users to build their own 
applications to access and modify the underlying EHR. (No doubt this is 
a significantly more complicated aim than just writing an 'approved' 
application in python, wxPython and SQL). It will, however, be unique, 
more adaptable and scaleable, and allow many more people to come and 
play with us!