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

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

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

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

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

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…

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…

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…

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…

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.

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

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

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

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

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

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

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

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)

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

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

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)

Push Workflow – X-Ray Clinic

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

Example Implementation Groupings

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

Requesting Cancel

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.3.1.2 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

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

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