Specimens tested so far :

1. MCL at 3%, 6% and 9 % strain at 20%/s, 20%/s repeated, 15/s, 100%/s (4 tests)

2. Medial femoral cartilage (FMC) under confined compression, unconfied compression and tension at 5,10,15% strain at 20%/s and 10%/s. (6 tests)

3. Medial meniscus under confined compression, unconfied compression and tension at 5,10,15% strain at 20%/s and 10%/s. (6 tests)

4. Patellar cartilage (PTC) under confined compression, unconfied compression at 5,10,15% strain at 20%/s and 10%/s. (4 tests)

Notable observations:

1. In all MCL tensile tests, there was a noticeable rise in force even after the displacement stopped increasing. Test repeated at various strain rates. Same behavior observed.

2. for smaller samples, mainly compression samples, it is observed that the acceleration is slower especially for the first step/5% strain (improves for steps 2 and 3: This is consistent for all compression tests).

3. MCL was tested at 20%/s twice. The specimen was not removed from clamps between these two tests but there was a noticebale difference in initial length measurement (11.38 mm vs 12 mm ). For future tests , it will be useful to either measure the dimensions again or test it at 5% strain after the sample has rested without load for a while to determine whether there was any sample damage.

4. Time taken to apply the desired strain were consistently higher ( time : 4 to 20 ms longer than desired) (takes time to acclerate and decelerate). This is true even for protocol steps where speed is very low (move relative to apply preconditioning cycles, 0.05 mm/s).

Other notes:

1. These tests cover all representative tissue types and tests.

2. Samples were tested at other than 20%/s strain rate to ensure that 20%/s can be used as a safe value (particularly for compression samples).

3. Hold times were 2 min.

4. There was atleast 30 min wait (no load) before testing the same specimen again.

5. A total of 20 tests were conducted. Additionaly 5 full tests (3 strain levels with 2 min hold time) were run with no samples to compare the system behavior with and without sample. These tests were compression tests with femoral and patellar cartilage specific dimensions (20%/s and 10%/s for femoral cartilage and 10%/s,5%/s and 100%/s for patellar cartilage).

6. The data is uplaoded to Midas under oks00TR ( TR = trial). On the Mach 1 computer it is located at C:/Mach-1-Data/oks/oks00TR.

7. All tests conducted at default PID settings.

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Dimensions:

MCL: Tensile (L= 11.389 mm, W=2 mm, T= 1.14 mm )

FMC : Compression (T= 2.12 mm, D= 5 mm)

FMC: Tensile (L=6 mm, W=1mm, T=1 mm)

MNS: Compression (T=3.13 mm, D= 5mm)

MNS: Tensile ((L=6.915 mm, W=1mm, T=0.596 mm)

PTC: Compression (T=2.58 mm, D=5mm)

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MCL: 20%/s strain, 3% strain

Slope (mm/s):	-2.2784 (desired : 2.27 mm/s)

RMSE (mm):	0.0038

Delta X (s): -0.1640 (desired: 0.15 s)

Delta Y (mm):	0.3410 (desired : 0.34 mm)

MCL : 9% strain, 20%/s

Slope (mm/s):	-2.2762 (desired : 2.27mm)

RMSE (mm):	0.0038

Delta X (s):	-0.1640 (desired : 0.15 s)

Delta Y (mm):	0.3420 (desired : 0.34mm )

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FMC, unconfined compression

5% strain

10 % strain