Options for architectural approaches
of semantic services in eHDSI
• Three models are presented
– Centralized. Two options: (1) fully centralized and (2) centralized model
appended with national extensions. Both options were used during epSOS
in different countries, and (2) is somewhat closer to actual reality.
– Distributed. No centralized terminology server involved.
– Hybrid. Terminology servers maintained both by the eHDSI Solution
Provider and member states.
• Operations and processes are presented on a very coarse level.
– A separate table with definitions is provided.
• Assumption: need to define a MVP (minimum viable product) for
terminology services for Wave 1 countries.
– The solution is not final and will be developed further in the next stages.
– FH Dortmund Terminology Server or a similar technical solution with only
minor extensions must suffice for MVP.
– The selected architectural approach should also work in future stages of
development.
Centralized model
Central terminology server
Terminology
server app
eHDSI
Solution
Provider
Code system upload
Code system maintenance
CTR
SDO
License agreements
Code system and value set
download
Value set upload
Value set maintenance
User interface app
Central terminology
repository
Concept translation
and concept
association upload
and maintenance
Nationally used code
system and value set
upload and maintenance
Note that this model is not fully
centralized as a lot of
maintenance work is done by
national terminology experts.
There are also nationally used
code systems and value sets,
maintained in national solutions.
National
terminology
experts
Code system
download
Value set download
Concept association
download
NCP
TSAMsync
Standards
development
organizations
Runtime access to
code system data
LTR
Local terminology
repository
Document transformation
TSAM
transformation
service access
manager
TM
transformation
manager
Protocol
terminators
National
connector
NI
National
infrastructure
Centralized model
eHDSI
Solution
Provider
+ potential national extensions
Central terminology server
Terminology
server app
Code system upload
Code system maintenance
CTR
SDO
License agreements
Code system and value set
download
Value set upload
Value set maintenance
National
bodies
User interface app
Code system, value set,
concept translation and
concept association
upload and maintenance
Nationally used code
system and value set
upload and maintenance
National
terminology
experts
National
terminology
server
Cooperation
Value set download
Concept association
download
Runtime access to
code system data
NCP
TSAMsync
License agreements
Code system and value
set download
Central terminology
repository
Concept translation
and concept
association upload
and maintenance
Code system
download
Standards
development
organizations
Runtime access to
code system data
LTR
Local terminology
repository
Document transformation
TSAM
transformation
service access
manager
TM
transformation
manager
Protocol
terminators
AND/OR
Code
system download
Value set download
Concept association
download
National
connector
NC
LTR
Runtime access to
Document
code system data
transformation
Other NI parts
Centralized model: pros and cons
• Provides a centralized
solution for countries
with no national
terminology servers.
• Makes translation work
status and progress
visible.
• Translations available for
use by other countries, if
allowed.
• Double work for some
(both national and
international) code
systems and value sets in
countries with national
terminology servers.
• No support for national
extensions of code
systems and value sets.
• Poor tools for the
maintenance of the LTR
(only database access
and TSAM-sync)
Distributed solution
eHDSI
Solution
Provider
Fully distributed model
SDO
Standards
development
organizations
License agreements
Code system and value
set download
Information on required
code systems and value sets
National
terminology
experts
Not realistic?
Information on required
code systems and value sets
Cooperation
National
bodies
Code system, value set,
concept translation and
concept association
upload and maintenance
Code system download
Value set download
Concept association
download
National
terminology
server
Runtime access to
code system data
NCP
Local
sync app
Runtime access to
code system data
LTR
Local terminology
repository
Document transformation
TSAM
transformation
service access
manager
These components could be skipped if national
connector takes full care of document
transformations
TM
transformation
manager
Protocol
terminators
AND/OR
Code
system download
Value set download
Concept association
download
National
connector
NC
LTR
Runtime access to
Document
code system data
transformation
Other NI parts
Distributed model: pros and cons
• No dependency on a
centralized service, no need
to maintain it.
• Possibility to reuse a national
solution or introduce a
national terminology server.
• No duplication of translation
work.
• Native support for nationally
used code systems, value sets
and national extensions.
• Translation work status and
progress is not visible and
needs to be reported in other
ways.
• Translations not available to
other countries without extra
sync mechanisms.
• Extra work for establishing
local sync mechanisms
between terminology server
and NCP.
• Need for centralized master
value catalogue distribution is
not fully eliminated (but Excel
would do?).
Hybrid model
eHDSI
Solution
Provider
Central terminology server
Terminology
server app
Code system upload
Code system maintenance
CTR
SDO
License agreements
Code system and value set
download
Value set upload
Value set maintenance
License agreements
Code system and value
set download
National
bodies
User interface app
Central terminology
repository
Information on required
code systems and value sets
TSAMsync
Code system, value set,
concept translation and
concept association
upload and maintenance
National
terminology
experts
NCP terminology server
Terminology
server app
Standards
development
organizations
LTR
User interface app
Concept translation
and concept
association
maintenance
National
terminology
server
Local terminology repository
Other NCP software
Runtime access to
code system data
Runtime access to
code system data
TSAM
transformation
service access
manager
TM
transformation
manager
Protocol
terminators
AND/OR
Code
system download
Value set download
Concept association
download
National
connector
NC
LTR
Runtime access to
Document
code system data
transformation
Document transformation
Other NI parts
Hybrid model: pros and cons
• Possibility to reuse a national
solution or introduce a national
terminology server.
• No duplication of translation
work.
• Nationally used code systems,
value sets and extensions are
easy to add locally or they may
be used directly from the
national code server.
• Clear separation of centralized
and national terminology work,
also on the tool level.
• Good tooling for national LTR
maintenance.
• Translation work status and
progress is not visible and needs
to be reported in other ways.
• Translations not available to
other countries without extra
sync mechanisms.
• Need to maintain terminology
servers both at the NCPs and
centrally.