Synopsis
- All the attempts to evaluate the tissue mechanical testing and related protocols will be documented on this page.
Note: The force data will not be filtered.
- Force displacement data will be acquired at 2kHz.
- Load cell will be calibrated at the beginning of the test day.
- Appropriate changes will be made to ["Specifications/ExperimentationTissueMechanics"] once evaluation of protocols is complete.
- Details of testing protocols can be found at ["Specifications/ExperimentationTissueMechanics"]
Repeatability of test protocols
* This exercise will be used to evaluate whether the Mach 1 system can apply the same controls when the test environment is not changed. This will also help to determine whether there was any tissue damage/ altered tissue state during the test (if the controls remain the same).
- Ligament tensile test
- A ligament tensile sample will be tested at 3%, 6% and 9% strain at 20%/s strain rate.
- After the completion of first test, the sample will be allowed to rest in an unloaded state for 30 min.
- The sample will not be removed from the test environment.
- The sample will be tested again at 3%, 6% and 9% strain at 20%/s strain rate.
- The sample will be allowed to rest in an unloaded state for 30 min.
- The sample will be tested at 3%, 6% and 9% strain at 100%/s strain rate.
- The sample will be allowed to rest again in an unloaded state for 30 min.
- The sample will be tested again at 3%, 6% and 9% strain at 100%/s strain rate.
- Cartilage unconfined compression test
- A cylindrical cartilage sample will be tested under unconfined compression at 5%, 10% and 15% strain at 20%/s strain rate.
- After completion of the test, the sample will be allowed to rest in an unloaded state for 30 min.
- The sample will not be removed from the test environment.
- The sample will be tested again at 5%, 10% and 15% strain at 20%/s strain rate.
- The sample will be allowed to rest in an unloaded state for 30 min.
- The sample will be tested at 5%, 10% and 15% strain at 100%/s strain rate.
- The sample will be allowed to rest again in an unloaded state for 30 min.
- The sample will be tested again at 3%, 6% and 9% strain at 100%/s strain rate.
- Cartilage confined compression test
- Sample used for unconfined compression will now be tested under confined compression.
- All steps described above for unconfined compression test will be repeated.
- Cartilage tensile test
- A cartilage tensile sample will be tested at 5%, 10% and 15% strain at 20%/s strain rate.
- After completion of the test, the sample will be allowed to rest in an unloaded state for 30 min.
- The sample will not be removed from the test environment.
- The sample will be tested again at 5%, 10% and 15% strain at 20%/s strain rate.
- The sample will be allowed to rest in an unloaded state for 30 min.
- The sample will be tested at 5%, 10% and 15% strain at 100%/s strain rate.
- The sample will be allowed to rest again in an unloaded state for 30 min.
- The sample will be tested again at 3%, 6% and 9% strain at 100%/s strain rate.
Results
Reproducibility of test protocols
- The goal of this exercise is to evaluate whether the test protocols will produce the same results (evaluated through material property identification) provided the sample was not damaged during testing.
- The samples tested in previous section will be removed from the test set up and stored before being retested.
- Sample dimensions will be measured again before testing.
Results
Assessment of desired rates and strain levels
Results
Zero force (find contact) with and without force filter
Results
Assessment of force and displacement data alignment
Results
Assessment of positioning of clamps to set zero position
Results
Thickness measurement repeatability and reproducibility
Results
Length measurement repeatability and reproducibility
Results
Standardization of camera positions using bigger lens