MedBiquitous XML Design Patterns Rachel Ellaway 1, Valerie Smothers 2, Joel Farrell 3, Daniel Rehak 1 Northern Ontario School of Medicine, 2 MedBiquitous, 3 IBM 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 time 0 attributesvocabularies 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 Ellaway Valerie Smothers DP: given:family

MedBiquitous XML Design Patterns Rachel Ellaway 1, Valerie Smothers 2, Joel Farrell 3, Daniel Rehak 1 Northern Ontario School of Medicine, 2 MedBiquitous, 3 IBM MedBiquitous 2012