• ModelReuse

Goals

The fundamental goal of the Model Reuse phase is to utilize models re-calibrated and benchmarked in the Model Benchmarking phase to demonstrate utility of the models in cases for which the models are not necessarily developed for or validated against.

Specific goals of the Model Reuse phase are

• To conduct simulations with re-calibrated models with experimental joint coordinate system using,
  • Passive flexion loading
  • Pivot shift loading
  • Weight bearing x-ray loading

• To document and disseminate modeling & simulation (M&S) processes, including specifications and protocol deviations

• To document and disseminate load cases, parameters and results of Reuse cases.
• To document and disseminate reuse case models including changes in virtual anatomical and mechanical representations of model components.
• To document and disseminate simulation results.

Tentative Timeline

Specimen information

oks003 from Open Knee(s):

• Demographics
  • Left knee
  • Age: 25 years
  • Gender: Female
  • Height: 1.73 m
  • Weight: 68 kg
  • BMI: 22.8

DU02 from Natural Knee Data:

• Demographics
  • Right knee
  • Age: 44 years
  • Gender: Male
  • Height: 1.83 m
  • Weight: 70.31 kg
  • BMI: 21.02

Simulation Cases

Each team will simulate three simulation cases.

• Passive flexion:
  • Prediction of knee joint kinematics-kinetics from 0° to 90° flexion where remaining rotations and translations are free to find equilibrium.
  • Flexion prescribed on moving object at a femur fixed flexion axis.
  • Benchmarked models in registered, experimental coordinate systems
  • Conditions
    • No additional forces and moments
    • 1 BW compressive joint force applied on moving object at tibia fixed superior-inferior axis.
• Pivot shift: Simulation scenario with knee loaded by prescribed flexion from 0° to 90° while simultaneously applying and internal rotation torque of 5 Nm and valgus torque of 10 Nm.
  • Prediction of knee joint kinematics-kinetics from 0° to 90°
  • Prediction of clinical anterior translation of tibia (along tibia fixed anterior axis)
  • (Optional) Prediction of ACL forces and strains in intact joint case
  • Flexion prescribed on moving object at a femur fixed flexion axis.
  • Internal rotation torque applied on moving object at a tibia fixed superior-inferior axis.
  • Valgus torque applied on moving object at a tibia fixed anterior-posterior axis.
  • Conditions
    • Intact anterior cruciate ligament
    • Resected anterior cruciate ligament
• Weight-bearing x-ray: Simulation scenario with knee loaded by prescribed flexion from 0° to 15° degree and ½ body weight.
  • Prediction of cartilage contact stresses.
  • (Optional) Prediction of medial and lateral contact forces
  • Flexion prescribed on moving object at a femur fixed flexion axis.
  • ½ BW compressive joint force applied on moving object at tibia fixed superior-inferior axis.

Deliverables

Modeling & Simulation Outputs

Intermediate and End-Point M&S Outputs

Two packages representing final outcomes of Model Reuse phase will be the outputs of this phase. The focus is the complete curation of the processes and results of each individual team's Model Reuse activities.

• Package (*.zip) collating M&S Outputs using Open Knee(s)

  • End-point M&S Outputs such as

    • Working model including simulation cases in a format preferred by modeling team
    • Simulation results in a format preferred by modeling team

• Package (*.zip) collating M&S Outputs using Natural Knee Data

  • Similar to package described above but utilizing Natural Knee Data

Documentation of M&S Outputs

Two document sets should provide information to help navigate the M&S output package and to describe what M&S Outputs are (not how they are obtained).

• Document (in source, e.g., *.odt, *.docx, etc., and PDF formats) describing M&S Outputs using Open Knee(s) data

  • Metadata for the document - authors, date, contact information
  • Information to navigate the package

  • Information to describe what each M&S Output is

• Document (in source, e.g., *.odt, *.docx, etc., and PDF formats) describing M&S Outputs using Natural Knee Data

  • Similar to document described above but utilizing Natural Knee Data

Modeling & Simulation Processes

An important set of deliverables are the documentation of the M&S processes, i.e. the individualized workflows to transform earmarked data and re-calibrated models with experimental joint coordinate system to M&S outputs. The documents will include Specifications, to provide each team's initial plans to obtain M&S outputs, and Protocol Deviations, to describe modifications to Specifications during the execution of the initial plans. Ideally, when a third-party modeler has the earmarked data, specifications, and protocol deviations, they can follow the steps of the modeling team to reproduce their disseminated M&S outputs.

Specifications

Specifications documents are aimed to describe individual steps to obtain M&S outputs. The detail should be provided in a manner that other teams can reproduce the decision making process of the modeler. Any subjective and arbitrary decisions should be noted and as much insight as possible should be provided for justification and reproduction of these decisions. This document should be prepared and disseminated before M&S activities start.

• Specifications document (in source, e.g., *.odt, *.docx, etc., and PDF formats) describing M&S Processes using Open Knee(s) data

  • Metadata for the document - authors, date, contact information

  • Information to describe what each target M&S Output is

  • Information to describe how each target M&S Output will be obtained

  • Anticipated burden of the workflow

• Specifications document (in source, e.g., *.odt, *.docx, etc., and PDF formats) describing M&S Processes using Natural Knee Data

  • Similar to document described above but utilizing Natural Knee Data

Protocol Deviations

If specifications need to be updated during activities to go from earmarked data to M&S outputs, these should be documented as protocol deviations. As much insight as possible should be provided for justification of the deviation. This document should be prepared during M&S activities and disseminated along with M&S outputs.

• Protocol Deviation document (in source, e.g., *.odt, *.docx, etc., and PDF formats) describing M&S Processes using Open Knee(s) data

  • Metadata for the document - authors, date, contact information
  • Collated set of protocol deviations, each describing
    • What is the deviation in relevance to Specifications?

    • Which M&S output does the deviation impact?

    • Who implemented the modification?
    • When was the modification made?
    • What is the justification for deviation?
  • Actual burden of the workflow

• Protocol Deviation document (in source, e.g., *.odt, *.docx, etc., and PDF formats) describing M&S Processes using Natural Knee Data

  • Similar to document described above but utilizing Natural Knee Data

Package for Comparative Analysis

Two packages will be prepared to curate M&S Outputs and process documentation of each team; one starting with data from Open Knee(s), the other utilizing Natural Knee data. The M&S Output files submitted by the individual teams will be organized in these packages and provided as is with the possible exception of renaming of master package files. The documents will be provided as is. Yet, additional organization of output description and process documentation may be necessary to meet third-party requirements or recommendations (see guidance from #USFDA, #ASME, #NASA, #Erdemir2015).

• Package of M&S outputs and processes for Open Knee(s)

  • Cleveland Clinic team

    • M&S outputs package file

    • M&S outputs documentation files

    • M&S processes specifications documents

    • M&S processes protocol deviation documents

  • University of Denver team

    • M&S outputs package file

    • M&S outputs documentation files

    • M&S processes specifications documents

    • M&S processes protocol deviation documents

  • Cleveland State University team

    • M&S outputs package file

    • M&S outputs documentation files

    • M&S processes specifications documents

    • M&S processes protocol deviation documents

  • Auckland Bioengineering Institute team

    • M&S outputs package file

    • M&S outputs documentation files

    • M&S processes specifications documents

    • M&S processes protocol deviation documents

  • Hospital for Special Surgery team

    • M&S outputs package file

    • M&S outputs documentation files

    • M&S processes specifications documents

    • M&S processes protocol deviation documents

• Package of M&S outputs and processes for Natural Knee

  • Cleveland Clinic team

    • M&S outputs package file

    • M&S outputs documentation files

    • M&S processes specifications documents

    • M&S processes protocol deviation documents

  • University of Denver team

    • M&S outputs package file

    • M&S outputs documentation files

    • M&S processes specifications documents

    • M&S processes protocol deviation documents

  • Cleveland State University team

    • M&S outputs package file

    • M&S outputs documentation files

    • M&S processes specifications documents

    • M&S processes protocol deviation documents

  • Auckland Bioengineering Institute team

    • M&S outputs package file

    • M&S outputs documentation files

    • M&S processes specifications documents

    • M&S processes protocol deviation documents

  • Hospital for Special Surgery team

    • M&S outputs package file

    • M&S outputs documentation files

    • M&S processes specifications documents

    • M&S processes protocol deviation documents

Guidance

How to prepare and submit Specifications?

Specifications are concerned about documentation of the processes to generate M&S outputs. This information is intended to be provided separately for processing of both data sets to capture nuances in response to variable re-calibrated models and quality. This documentation will be provided before execution of Model Reuse activities to demonstrate the path each modeling team has chosen. Specifications should be in a detail such that other modeling teams can follow the steps to reproduce M&S outputs. When possible, justifications to support modeling & simulation decisions should be provided.

Recommended content for Specifications includes:

• Metadata for the document - contributors, contact information for corresponding author, date of document.

• Summary of data utilized with the M&S processes.

• Overview of target M&S outputs and M&S processes - similar to summarizing it in a scholarly publication.

• Detailed descriptions of target M&S outputs (consult Erdemir et al. (2012), for completeness)

  • Complete Reuse case model
    • Anatomy
    • Mechanical properties
    • Coordinate systems
    • Loading and boundary conditions (for the simulation cases)
    • Interactions between model components (contacts, ties)
  • Simulation cases
    • Loading and boundary conditions
    • Target metrics for predictions
    • Anticipated results

• Detailed descriptions of M&S processes to get the target M&S outputs

  • Steps to implement load cases as loading and boundary conditions
  • Steps to perform simulations
  • Burden
    • Software requirements
    • Hardware requirements
    • Anticipated man hours and expertise level
    • Computational cost
• References

Each team will submit two sets of documents, one for Model Reuse using Open Knee(s) data and another for Model Reuse using Natural Knee data. Each set will include the source document, i.e., in preferred format that it is written, and as a PDF copy. The documents should be submitted by any convenient means - e-mail, file sharing, upload to project site, etc. Ahmet Erdemir, erdemira@ccf.org, will push the submitted documents to the project site in the Documents section with labeling indicative of modeling phase, modeling teams, and data source.

How to prepare and submit Protocol Deviations?

It is likely that initial specifications may need to be modified to accomplish Model Reuse activities. These modifications, i.e. Protocol Deviations, should be documented during Model Reuse activities. Each protocol deviation should include information to understand who did, what and when, and why. The documentation should be in a detail such that other modeling teams can utilize it along with specifications to reproduce M&S outputs. This document should also include the actual burden of M&S activities including changes in software and hardware requirements, and deviations from anticipated labor effort and computational cost. Protocol Deviations should be collated in two sets of documents (one for using Open Knee(s) data and another for Natural Knee data). The documents will be provided after execution of Model Reuse activities in source form, i.e., in preferred format that it is written, and as a PDF copy. The documents should be submitted by any convenient means - e-mail, file sharing, upload to project site, etc. Ahmet Erdemir, erdemira@ccf.org, will push the submitted documents to the project site in the Documents section with labeling indicative of modeling phase, modeling teams, and data source.

How to curate, document and submit Modeling and Simulation Outputs?

All M&S outputs should be provided in their preferred format, i.e., accommodating individual teams' workflows. Each team should provide two packages (one for Open Knee(s) data and another for Natural Knee data) as a compressed archive (e.g. *.zip). For each package, an accompanying document should describe M&S outputs - in source form, i.e., in preferred format that it is written, and as a PDF copy. This information should focus on i) file descriptors and formats, and folder organization to help navigate the provided content and ii) what actually each M&S output is (NOT how they are obtained). The latter should be reflective of the description of target intermediate and final M&S products of Specifications. It should also be indicative of necessary information for other modeling teams to judge the nature and extent of the provided content. The packages should be submitted by any convenient means - e-mail, file sharing, upload to project site, etc. Ahmet Erdemir, erdemira@ccf.org, will push the submitted packages to the project site in the Downloads section with labeling indicative of modeling phase, modeling teams, and data source.

Preparing a package for Comparative Analysis

All material will likely need to be reorganized and converted to respond to third-party requirements for comparative analysis (see guidance from #USFDA, #ASME, #NASA, #Erdemir2015). Nonetheless, this should not prevent individual M&S teams to personalize their workflows and documentation style. Preparation of a package for comparative analysis will collate M&S outputs and documents submitted by the individual teams. M&S outputs will be provided in formats as delivered by the teams. Documentation may need to be reorganized using source copies of documentation from individual teams. Ahmet Erdemir, erdemira@ccf.org, will submit the prepared package to the third-party by any convenient means - e-mail, file sharing, upload to project site, etc.

References

Erdemir, A., Mulugeta, L. and Lytton, W. W. Ten “not so” simple rules for credible practice of modeling and simulation in healthcare: a multidisciplinary committee perspective, 2015 Biomedical Engineering Society / Food and Drug Administration Frontiers in Medical Devices Conference: Innovations in Modeling and Simulation, May 18-20, 2015, Washington, DC. Available at: https://simtk.org/svn/cpms/doc/posters/fmd_2015.pdf.

Erdemir, A., Guess, T. M., Halloran, J. P., Tadepalli, S. C. and Morrison, T. M. (2012) Considerations for reporting finite element analysis studies in biomechanics, Journal of Biomechanics, 45, 625-633. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3278509/.

U.S. Food and Drug Administration. Reporting of Computational Modeling Studies in Medical Device Submissions. Available at: https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/UCM381813.

NASA-STD-7009: Standard for Models and Simulations. Available at: https://standards.nasa.gov/standard/nasa/nasa-std-7009.

ASME V&V American Society of Mechanical Engineers - Committee Pages - V&V 40 Verification and Validation in Computational Modeling of Medical Devices. Available at: https://cstools.asme.org/csconnect/CommitteePages.cfm?Committee=100108782.