Recurring Meeting of Cleveland Clinic Core Team

Date: August 25, 2015

Time: 10:30 AM EST

Means: In person meeting

Attendees:

1. Ahmet Erdemir
2. Craig Bennetts
3. Snehal Chokhandre
4. Robb Colbrunn
5. Tara Bonner

Agenda:

1. Discuss immediate action items from the last meeting.
2. Finalize tissue testing protocol evaluation plan.
3. Discuss FE modeling direction, particularly utilizing knowledge generated by summer students.
4. Decide immediate action items for the next meeting.
5. Other.

Immediate Action Items:

• Ahmet
  • Disseminate the remainder of joint mechanics testing data.
  • Prepare flowcharts to describe data flow for pre-processing of joint kinematics/kinetics data.
• Craig
  • Continue meshing of Open Knee(s) - Generation 1 in IA-FEMesh.
• Snehal
  • Follow up with specimen suppliers for timely acquisition of additional specimens.
  • For tissue testing protocol evaluation, add testing to quantify uncertainties associated with fluid forces and inertial forces.
  • Document uniform sample preparation.
• All
  • Evaluate Scientific Data journal for its suitability for publishing Open Knee(s) data.

Ongoing Action Items:

• Craig
  • Anatomical imaging manuscript.
  • Large-scale analysis of simulation parameters for convergence.
• Snehal
  • Pivot shift manuscript.

  • Cruciate ligament modeling & simulation.

• Robb
  • Patellofemoral joint experimentation manuscript.
• Tara
  • Tibiofemoral joint experimentation manuscript.

Notes:

1. Discuss immediate action items from the last meeting.
   • Ahmet disseminated joint mechanics data for oks001. There were no index files in the folders. He put readme files in empty folders and a detailed readme file in the main folder. Ahmet also provided a detailed description of the dissemination workflow in the wiki page on experimentation for joint mechanics under the heading "Data Dissemination". He will disseminate the rest of the joint mechanics data for remaining specimens.
   • Craig placed the script for post-processing of simulation kinematics in the repository. He continued working with IA-FEMesh for meshing Open Knee(s) - Generation 1 geometries. Craig identified various features (mapping of vertices and edges, etc), if available, may allow appropriate and efficient meshing. He will contact Nicole Grosland and Vincent Magnotta (developers of IA-FEMesh) to ask about potential availability of such features or other workarounds. He will continue exploring IA-FEMesh and will start evaluating Salome for hexahedral meshing.
   • Snehal has not received any feedback from specimen suppliers, she will follow up.
   • Ahmet emphasized that each team member should take a look at the Scientific Data journal to evaluate how a data manuscript is organized for publication there. It is a possibility that Open Knee(s) - Generation 2 data will be submitted there for publication.
2. Finalize tissue testing protocol evaluation plan.
   • Snehal asked the team if testing at 100%/s strain rate is necessary. She reminded Ahmet that Mach-1 system had difficulties to sustain high speeds needed for 100%/s strain rate testing. The team may need to confirm the speed limits of the Mach-1 testing system by conducting simple tests. If not possible, 100%/s strain rate testing can be removed from the evaluation plan.
   • Snehal ordered the 10N and 1.5N load transducers. The wiki page should include the specific transducer that will be used for the specific tissue type.
   • Robb indicated the need to evaluate the influence of inertial forces and buoyancy. Snehal will come up with a strategy to quantify these, i.e., place the tension grip (tension) or indenter (compression) without sample at various depths to measure and later compensate (post-process) for buoyancy forces.
   • For tension testing, to estimate the zero position (and therefore reference point for gauge length calculation), the evaluation test needs to bring grips next to each other multiple times, e.g., 10X, get displacement, and report uncertainty. The gauge length uncertainty will most likely be an additive of the zero position error and zero force displacement (find contact) error.
   • To evaluate correspondence of tests conducted at different days on the same sample, instantaneous and steady-state moduli should be calculated and compared.
   • For optical tissue thickness measurement, the camera should be positioned such that the field of view includes approximately 2 cm ruler height. For evaluation purposes, thickness should be measured both optically and by the contact method.
   • Ahmet noted to split the evaluation timeline into two; for development and for testing. The development, i.e. sorting out all the resources and equipment needed for testing, will likely take about three weeks. He advised Snehal to prepare processing scripts before testing starts as these can be used while collecting data. The testing will require ligament samples to stay in an unfrozen state for 1 day; cartilage and meniscus samples will stay in an unfrozen state for 3 days. For a given sample and test type, repeatability and reproducibility testing will be conducted within a day. As a result, any potential degradation of specimen overnight may not affect relative comparisons. The whole evaluation testing will likely take about 2 weeks.
   • Ahmet wondered about the uniform sample preparation processes and punching and cutting of the samples. Snehal summarized the strategies she has been employing. She will document these in more detail in the wiki.
   • The group also had a discussion on the meaning of "repeatability" and "reproducibility". Per Robb's comment, it will be useful to describe in detail what we mean by these within the context of tissue testing protocol evaluation.
3. Discuss FE modeling direction, particularly utilizing knowledge generated by summer students.
   • Craig consolidated all the new springs from students' studies to the Open Knee(s) - Generation 1 model. He will complete the convergence optimization to assess how spring definitions constrain or affect joint kinematics/kinetics and facilitate convergence.
   • The joint mechanics data to be processed to drive simulations. Ahmet's flowchart to extract relevant information from raw data sets will be helpful.
   • The team needs to evaluate segmentation conducted by students to determine workflows to accomplish it for the next generation models.
4. Decide immediate action items for the next meeting.
   • See Immediate Action Items above.
5. Other.
   • Snehal requested changes in scheduling of imaging by contacting the imaging facility. Ahmet added that he will be away around October 8-10, 2015.