MedBiquitous XML Design Patterns

Rachel Ellaway1, Valerie Smothers2,

Joel Farrell3, Daniel Rehak1Northern Ontario School of Medicine, 2MedBiquitous, 3IBM

MedBiquitous 2012

Conflict of interest

We have no involvement with industry that creates a conflict of interest to disclose with respect to this workshop

Overview

• MedBiquitous develops “information technology standards for healthcare education and competence assessment … based on XML and Web services standards”

• We translate real world needs to technical models and frameworks

• How can we improve MedBiquitous’ community in doing this work

• Try seeing the world in terms of design patterns …

Design Patterns

Design patterns

• From architecture – Andrew’s ‘pattern language’

• A “pattern describes a problem that occurs over and over again … and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice”

• Vocabulary = named, described solutions to problems … called "design patterns”

• Also syntax (context) and grammar (method)

A Pattern Language, Christopher Alexander, with Sara Ishikawa, Murray Silverstein, Max Jacobson, Ingrid Fiksdahl-King, and Schlmo Angel, Oxford University Press 1977

Design patterns in s/w

• OO – reusability, efficiency, understandability

• creational patterns – how entities are defined

– Properties, vocabularies, classes

• structural patterns – how entities are grouped and related

– Trees, taxonomies, objects, libraries

• behavioral patterns – what entities can do

– Rules, state, interpret

Design patterns in interop

• creational patterns – how entities are defined

– properties, vocabularies, classes

• structural patterns – how entities are grouped and related

– trees, taxonomies, objects, libraries

• behavioral patterns – what entities can do

– rules, state, interpret

Design patterns in interop

Four main layers:

• Vocabularies

• XML

• Schema design

• Architectures

Vocabulary Design Patterns

• Defined descriptors• Required (unchanging)• Recommended

– may change– may be ignored– may be augmented

• Global – MeSH, UMLS• Specific• Language issues, translation, syntax etc

XML Design Patterns

• XML is itself a pattern• Tree - nodes• Attributes• Vocabularies• Namespaces• Special handling - PCDATA

XML Design Patterns

<Properties> <Counters> <Counter id="608" isVisible="true"> <CounterLabel>time</CounterLabel> <CounterInitVal>0</CounterInitVal> </Counter> </Counters></Properties>

attributes vocabularies

entities

tree

Schema Design Patterns

• Single tree – healthcare LOM– Contiguous, equivalent concepts

• Multiple trees – MVP– Non-contiguous, non-equivalent concepts

Single tree schema: MedBiquitous’ Healthcare LOM

From IEEE

MedBiquitous Extension

Multiple tree schemas: MedBiquitous’ Virtual Patient

Virtual Patient Data

Media Resources

Data Availability Model

Activity Model

SCORM package

Architecture Design Patterns

• Common XML data structures• Reuse vocabularies – MeSH, UMLS• Referencing other standards:

– Reuse MedBiquitous S&S, whole or part– External S&S can often be reused (check

license) e.g. content packaging, LOM etc

• xx

Architecture Design Patterns

person resource

competency

Why is this important?

• MedBiquitous’ work is a community effort

• Some standards development processes hindered by limited familiarity with DPs

• Interop DP literacy can help to streamline and accelerate standards development

Design patterns in interop

Many layers:

• Vocabularies

• XML

• Schema design

• Architectures

Look for them, see them, understand them, use them

One from this list?

Is this a tree?

Apples and architraves?

What classes, functions and architectures can we reuse?

Design Patterns

Thank you!

Rachel Ellawayrellaway@nosm.ca

Valerie Smothersvsmothers@jhmi.edu

DP: given:familyuser@domain

MedBiquitous XML Design Patterns

Rachel Ellaway1, Valerie Smothers2,

Joel Farrell3, Daniel Rehak1Northern Ontario School of Medicine, 2MedBiquitous, 3IBM

MedBiquitous 2012