1. Kevin O’Donnell Toshiba Medical Systems
Flexible Workflow using UPS: Unified Procedure Step
Kevin O’Donnell Toshiba Medical Systems

2. UPS Goals Add “Push Workflow” & “Create Workitem”
Request another system to add item to worklist
Simplify Implementation
GPWL had N:M relation of SPS:PPS
State diagram was very complex
Add “Cancel Request”
Improve Status/Result Monitoring
Getting PPS feed was awkward; required configuration and forwarding

3. Interesting UPS Features
Remote create
Task Locking by performer
Deletion Locking by watchers
Subscription-based Monitoring
“Gift Subscriptions”
Push, Pull, and Watch Workflows
Sub-contracting
1-to-1 relationship between SPS and PPS
4 SOP Classes operating on 1 IOD

4. UPS Architecture One object Four SOP Classes
Each item on a worklist is a UPS Object
UPS Object = Unified Procedure Step IOD
Unified = contains details of both the requested task & the performed task
Four SOP Classes
UPS Push SOP Class
UPS Pull SOP Class
UPS Watch SOP Class
UPS Event SOP Class

5. UPS Object A UPS Object has its attributes grouped into 4 Modules:
(this does not affect processing; just for logical organization)
UPS Object
Sched. Task Details
Progress
Perf. Task Details
Relationship

6. UPS Object Modules UPS Object Sched. Task Details Progress
Perf. Task Details
Relationship
Relationship Module
Patient demographics
Admission details
Order details
Requested Procedure
Accession #
- Reason for Requested Procedure
Requesting physician/department
etc…

7. UPS Object Modules UPS Object Sched. Task Details Progress
Perf. Task Details
Relationship
Scheduled Proc. Info. Module
- Priority
- Requested perform./completion time
- Requested resources/location
- Requested Procedure descrip./codes
- Requested Processing parameters
List of Input data IDs
Input Data Availability Flag
etc…

8. UPS Object Modules UPS Object Relationship Sched. Task Details
Progress
Perf. Task Details
Relationship
Progress Module
- UPS State (Scheduled, In-Progress, Completed, Canceled)
Progress Status – Numerical (e.g. % complete)
Progress Status – Description (e.g. Annealing phase complete)
- Contact information for performer (e.g. phone #)
etc…

9. UPS Object Modules UPS Object Relationship Sched. Task Details
Progress
Perf. Task Details
Relationship
Performed Proc. Info. Module
- Time Performed/completed
- Performing resources/location
Performed Procedure descrip./codes
Performed Processing parameters
- List of Output data IDs
etc…

10. UPS State Diagram
NOTE: There is no suspend. If you want to put it back to scheduled after you make it in progress, you cancel your current one and create a duplicate.

11. Worklist Manager (SCP)
UPS Pull Workflow
Requester (SCU)
Worklist Manager (SCP)
Create UPS
Subscribe UPS
Query
Performer (SCU)
UPS State Event
Get UPS Contents
Get UPS Contents
UPS
UPS State “In-Progress”
3D Workstation
Set UPS Contents
UPS State “Complete”
Watcher (SCU)
Subscribe Global
UPS State Event
Dashboard System

12. UPS SOP Classes Each UPS Object is managed by a single SCP.
4 SOP Classes exist which can be used to operate on a UPS object.
Each SOP Class supports a few related operations.
SCU/SCP not required to implement all the SOP Classes. Can implement SOP Classes based on the operations it needs.
UPS Object
Sched. Task Details
Progress
Perf. Task Details
Relationship

13. UPS SOP Classes UPS Push SOP Class allows SCU systems to:
* create (push) a new worklist item (i.e. instance) on a worklist
* request cancellation of a worklist item
UPS Object
Sched. Task Details
Progress
Perf. Task Details
Relationship

14. UPS SOP Classes UPS Pull SOP Class allows SCU systems to: UPS Object
* query a worklist for matching items
* take ownership/control (pull) of a worklist item
* modify progress/status/result details for the worklist item
* finalize a controlled worklist item as Completed or Canceled.
UPS Object
Sched. Task Details
Progress
Perf. Task Details
Relationship

15. UPS SOP Classes UPS Object UPS Watch SOP Class allows SCU systems to:
Sched. Task Details
Progress
Perf. Task Details
Relationship
UPS Watch SOP Class allows SCU systems to:
* query a worklist for items of interest
* subscribe/unsubscribe for change events for one worklist item
* subscribe/unsubscribe for change events for all worklist items
* get details for a worklist item
* request cancellation of a worklist item

16. UPS SOP Classes UPS Object Relationship
Sched. Task Details
Progress
Perf. Task Details
Relationship
UPS Event SOP Class allows SCU systems to:
* receive change events for worklist items

17. UPS Task Locking For a UPS in SCHEDULED State:
(SCU does N-ACTION to IN-PROGRESS)
SCP generates a lock ID
(SCP returns lock ID to performing SCU)
For a UPS in IN-PROGRESS State:
N-SET without lock ID is rejected by SCP
N-ACTION to change state “ “
Of course, lock ID could be distributed, but be careful

18. Pull Workflow
SCP
SCU
3D Workstation
R I S
Give me a list of tasks that need to be done (C-FIND)
UPS
UPS
UPS
UPS
I will do that one (N-ACTION Set to IN-PROGRESS)
Record these details in the UPS (N-SET attribute values)
I am finished (N-ACTION Set to COMPLETE)

19. Pull Workflow – 3D Workstation
NOTE: solid lines are UPS Transactions. Dotted lines are other transactions.

20. Comparison to Modality Worklist
MWL is like UPS Pull-mode, except
UPS combines SPS and MPPS in a single object
UPS has extra features
UPS will not generally replace MWL
MWL does it’s (limited) job reasonably well
MWL has a large install base
UPS might supplement MWL for specific applications that need it’s features
e.g. Push Workflow for X-Ray clinics

21. Push Workflow
SCU
SCP
3D Workstation
R I S
Please perform this task (N-CREATE with these attribute values)
UPS
Notify me about progress for that task (N-ACTION Subscribe)
I have started to do that task (N-EVENT it is IN-PROGRESS)
I have updated details in the UPS (N-EVENT)
I am finished (N-EVENT it is COMPLETE)
Give me the result details of the task (N-GET these attribute values)

22. Push Workflow – X-Ray Clinic

23. Watch Workflow No central controller Examples:
Workstation watches flow of N-EVENTs: “System A did X”, “System B did Y”
Workstation decides “Hmmm, I think I will do this”
Workstation internally creates a UPS
Interested Subscribers are notified of Workstation activity via N-EVENT; N-GET details as needed
Examples:
CAD workstation sees N-EVENT that Mammo Acq. is complete; decides to do CAD processing
Reporting station sees N-EVENT that CAD is complete; decides to queue reading worklist for that study

24. Example Implementation Groupings

25. Deletion Locks & Reliable Watchers
Reliable Watcher (SCU)
Problem: SCP might delete a completed UPS before SCU gets needed details
(e.g. due to Network latency or outage)
Missing a UPS could prevent Watcher from:
monitoring completion
extracting details
creating subsequent UPS Instances,
referencing UPS 1 outputs as UPS 2 inputs
Mechanism
SCU Sets a Deletion Lock flag during subscription
SCP can’t delete UPS with outstanding Deletion Locks
SCU removes Deletion Lock after retrieving final state of UPS
SCP free to delete UPS after all deletion locks removed
SCP documents how it handles orphans

26. Requesting Cancel

27. Current DICOM Status Sup 96 (UPS)
Officially published as Frozen for Trial Use
Sup 74 (Radiotherapy Treatment Delivery Workflow)
Defines Treatment Delivery Objects
Documents use of UPS for RT
UPS references instances of RT Beams Delivery Instruction
Treatment Delivery System (SCU) pulls work from the Treatment Management System (SCP)
Z gives detailed example of UPS usage, specifying both the task and input objects
Sup 124 (Softcopy Display Mgt.)
Under development
Defines Display management/callibration Tasks & Results
Uses UPS to push Display Calibration jobs (with Task description) & convey Results

28. Current IHE Status IHE Radiation Oncology IHE Mammography
Planning to test Sup 74 workflow using UPS
IHE Mammography
expressed interest in UPS features; (not committed yet)
UPS could help handle complex cases such as:
Multi-pass Acquisition
Callbacks
CAD
Reading Worklists
IHE Radiology
no plan to replace Modality Worklist for acquisition workflow
will consider UPS when re-visiting Reporting Workflow and Post-processing Workflow
may profile Sup 124 when it’s ready

29. Questions?
> DICOM Status
> Sup 96