Weekly Update in lieu of Recurring Meeting of Cleveland Clinic Core Team
Date: March 28, 2017
Provided by: Snehal Chokhandre
Ongoing Action Items:
- Review drafts of data manuscripts for submission.
- Complete studies for tissue testing reproducibility.
- Continue tissue testing of Open Knee(s) specimens.
- Continue segmentation of Open Knee(s) specimens.
- Tissue testing.
- Snehal conducted two more unconfined compression tests on the second cartilage sample mentioned in last weeks updates (48 yr old specimen). The eepeatability for test 1 and 3 was acceptable (~2%). Tests 4 and 5 were conducted over the next two days. The error over the 4 tests (except test 2 which was repeated with shorter recovery time) was ~7%. These tests were conducted in PBS and with longer wait times between tests to give enough time for the sample to recover. This is a much better repeatability behavior than that noted for the first sample which was tested in saline and even some with longer than an hour of rest time.
- Based on the results for this sample, Snehal has been conducting similar week long unconfined compression tests on two other samples. She is currently testing two cartilage samples (for the 48 yr old specimen) from the same cartilage strips the previous samples were taken. The strip has been thawed three times so far. The goal is to test these two samples every day for 5 days so that each test for the given sample is repeated after ~24 hours. The samples are tested in PBS. This will provide a good indication of how longer recovery times affect the repeatability along with PBS. It will also provide data to assess changes in mechanical behavior over several days as well as effects of testing setup and procedures (as the entire procedure is repeated for every test including thickness measurement).
- So far, the repeatability for both the samples over two days appears fair. However for one sample the difference is ~3% and for the other ~6%. The sample with better repeatability also appears to be stiffer than the other. The stiffer sample is also about 3% less thick. Care is taken to keep the full thickness of the sample but in order to get a uniform thickness sample, it is necessary to shave off some tissue, sometimes on both the surfaces. Zonal and location dependent variations in properties even for the same specimen appear to exist.
- Once this set of testing is complete, Snehal will repeat the tests next week using other samples (may be from another location) with the updated preconditioning protocol (with ramps before and after preconditioning).
- Data manuscripts.
- No progress.
- No progress.
- None noted.