• RecurringMeetings
• 2017-05-02-Update

Weekly Update in lieu of Recurring Meeting of Cleveland Clinic Core Team

Date: May 02, 2017

Provided by: Snehal Chokhandre

Ongoing Action Items:

• Ahmet
  • Review drafts of data manuscripts for submission.
• Snehal
  • Complete studies for tissue testing reproducibility.
  • Continue tissue testing of Open Knee(s) specimens.
• All
  • Continue segmentation of Open Knee(s) specimens.

Notes:

1. Tissue testing.
   • 1. Snehal conducted unconfined compression tests on cartilage sample from the knee of the 48 year old donor. The goal was to include using PBS, longer rest times between tests (sample kept in fridge during rest) and starting preconditioning and stress relaxation 300 micrometers off of the 10g find contact position to capture data range increase from the instant any contact is established. It appeared that there was ~9% error in repeatability over 4 tests conducted over 4 days.
   • When adjusted to actual zero force-displacement point, the sample experienced load the earliest in test 3. Ahmet suggested calculating tangent moduli from the maximum strain loading ramps from the preconditioning protocols (0-15 % strain at 20%/s).
   • Snehal will continue the set of tests for cartilage for all test types and for both the knees from 48 years old and 78 years old donors.
2. Data manuscripts.
   • No progress.
3. Segmentation.
   • No progress.
4. Other.
   • Snehal and Ahmet met to discuss the simulation use case Snehal has been working on.
     • Snehal has been implementing patellofemoral cartilage compression simulation. The model consists of patella cartilage and truncated femur cartilage (region overlapping patella cartilage retained). Snehal used Blender to reposition the patella cartilage from neutral position to overlap femur cartilage manually. Femur cartilage geometry was also truncated using Blender. This positioning does not represent physiological placement and only used as a test simulation to learn the tools. Meshes were created in Salome and Preview/FEBio will be used to apply boundary conditions and run simulations.
     • Ahmet suggested using the meshing and model assembly pipeline developed by Ben Landis as well as manually performing all steps and comparing the usability and performance of the two methods (manual vs automated).
     • Both sets of geometries created by Craig Bennetts and Connor Lough will be tested to asses variations in model predictions due to variations in geometry resulted from two segmentation attempts.
     • Ahmet also suggested simulating indentation for the two patella cartilage geometries (varying material properties, indenter diameter, etc.).