• RecurringMeetings
• 2019-02-26

Recurring Meeting of Cleveland Clinic Core Team

Date: February 26, 2019

Time: 2:00 PM EST

Means: In person meeting

Attendees:

1. Ahmet Erdemir
2. Andrew Cho
3. Ariel Schwartz
4. Tammy Owings
5. Tyler Schimmoeller
6. Sean Doherty
7. Rici Neumann
8. Ellen Klonowski
9. Ben Landis (Skype)

Agenda:

1. Manuscripts update.
2. Data dissemination update.
3. In vitro testing status.

4. Modeling & simulation status.

5. Review of action items from past meeting.

   • https://simtk.org/plugins/moinmoin/multis/RecurringMeetings/2019-02-12

6. Decide action items for next meeting.
7. Other.

Ongoing Action Items:

• Rici
  • Re-submit in vivo indentation paper.
  • Meet with Ahmet and Sean to discuss model dissemination plan.
• Tyler
  • Continue development of in vitro and surgical tools data manuscripts.
  • Continue development of manuscript on tissue thickness measurement comparisons.
  • Revisit repeatability testing for tissue characterization.
• Ben
  • Review wiki page for model assembly of layered models.
  • Continue work on model assembly paper.
• Sean
  • Continue building layered models.
  • Build presentation on lumped model development/execution.
  • Meet with Ahmet and Rici to discuss model dissemination plan.
• Ellen
  • Explore/learn Sofa software.
  • Compile haptics libraries and SofaHAPI.
• Ahmet
  • Investigate Salome mesh quality metrics.
  • Review in vivo indentation paper revisions.
  • Meet with Rici and Sean to discuss model dissemination plan.
• Tammy
  • Assist in organization/clean-up of wiki.

Notes:

1. Manuscripts update.
   • In vivo indentation paper: Ahmet will work on reviewing revisions for re-submission next week.
   • In vitro data paper: Tammy and Rici have reviewed the draft. Tyler will work on implementing their comments/revisions and then submit to Ahmet for review.
   • Surgical tools data paper: Tyler is working to build the data overview plot script for the surgical tools data. Ahmet suggested plotting both positions/orientations and forces/moments all in the same coordinate system (bone).
   • Model assembly paper: Ben needs to work on some script issues prior to completing the manuscript, including (1) wedge elements and (2) normals.
2. Data dissemination update.
   • Stanford University team is in a supporting role. Cleveland Clinic team is waiting for integration of data dissemination sites to SimTK.
3. In vitro testing status.
   • Tyler is waiting to get 8020 (later this week or early next week).
   • His Mach 1 is not connecting right now, but he is working with Mark (Biomomentum) to get this fixed.
   • We are still waiting for arm and leg specimens from a final donor.
   • Tyler showed some figures from fat tissue testing. Tissue does not seem to recover when re-testing. Ahmet provided some input: the lack of reproducibility can be from (1) damage during testing, (2) sample does not recover (tissue behavior itself), (3) experimental reproducibility. He suggested maybe wrapping the fat tissue or starting with skin because it will likely be easier to achieve repeatability.

4. Modeling & simulation status.

   • Lumped models are all calibrated. Rici, Ahmet, and Sean will meet to discuss the dissemination.
   • Ahmet asked Sean to build a presentation to explain the workflow of the model building and calibration process of the lumped models.

   • Layered models: One model has been run to completion, however it took a lot of memory and will likely never run on a personal computer. He used wedge elements for the skin layer, however he had to aggressively smooth the skin layer to eliminate negative Jacobians in FeBio. This resulted in an overlap with the fat layer and therefore the model would only converge with a high penalty for the tie defined between the skin and fat layers. Ahmet suggested merging the nodes at the interface instead of defining a tie. Ahmet will look into some mesh quality metrics in Salome to assist with this issue.

   • Sean worked on making a layered model wiki page. Ben will look at it and add to it as needed.
   • When Sean was working with the lower leg, he was not able to extrude the skin from the fat layer because there was an area without fat that interfaced directly with the bone. Ahmet suggested lumping all tissues (except skin) together to find the extrusion surface.
   • Another issue that Ben brought up, was how to handle the boundary conditions between the fat/bone and skin/bone in special cases like the lower leg when the tissue is sparse on the anterior surface of the tibia.
   • Ahmet was concerned about penetration of the layers when using ties. This needs to be checked after the models are solved to make sure that node merging is not necessary.
   • Sean got a MULTIS model running in Abaqus. Ahmet will discuss with him further in the coming weeks. Ben suggested that the contact definitions within Abaqus are likely not the best, however surfaces should work okay.
   • FEBio surface definitions for skin has some issues because of different surface types within the mesh. Ben and Sean will look into this further.
5. Review of action items from past meeting.
   • All action items were related to the agenda items; refer to discussions above.
6. Decide action items for next meeting.
   • See Ongoing Action Items above.
7. Other.
   • Tammy will continue working with Ahmet and the rest of the team to help clean up the wiki pages for MULTiS.