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-- ["aerdemir"] DateTime(2016-04-14T17:41:11Z) Information below was ported from the main specifications page. It illustrates various iterations for smoothing, etc.

Following are examples (oks001) of distance maps (using MeshLab: Hausdorf distance) between various pairs of surfaces to assess:

1. spatial error between corresponding surfaces with varying levels of smoothing/refinement
2. distance between different model components (e.g. femur vs. femur cartilage, BACK SURFACE)
3. thickness of model components (e.g. cartilage):

To map tissue thicknesses (e.g. cartilage), opposing surfaces (i.e. BACK SURFACE, FRONT SURFACE) from a manifold (i.e. watertight) STL mesh were split into two complementary, shell STL mesh sets using Blender.

NOTE: all units are displayed in mm.

Smoothing Errors

UNSMOOTHED vs. SMOOTHED:

• femur cartilage, BACK SURFACE (REF; unsmoothed) vs. femur cartilage, BACK SURFACE (VCG smoothed, 0.7; ISO 10)
• femur cartilage, FRONT SURFACE (REF; unsmoothed) vs. femur cartilage, FRONT SURFACE (VCG smoothed, 0.7; ISO 10)

  • ImageLink("../oks001_FMC_vs_FMC_VCG_0.7_ISO_10.png", width=400, alt=oks001_FMC_vs_FMC_VCG_0.7_ISO_10)

    ImageLink(../oks001_FMC_vs_FMC_VCG_0.7_ISO_10_INF.png, width=400, alt=oks001_FMC_vs_FMC_VCG_0.7_ISO_10_INF)

Distance between Model Components

FEMUR vs. FEMUR CARTILAGE:

• femur (REF; VCG smoothed, 0.7; ISO, 10) vs. femur cartilage, BACK SURFACE (VCG smoothed, 0.7; ISO, 10)

  • ImageLink(../oks001_FMB_VCG_0.7_ISO_10_vs_FMC_SAME_AI.png, width=400, alt=oks001_FMB_VCG_0.7_ISO_10_vs_FMC_SAME_AI)

FEMUR CARTILAGE vs. FEMUR:

• femur cartilage (REF; VCG smoothed, 0.7; ISO, 10) vs. femur (VCG smoothed, 0.7; ISO, 10)

  • ImageLink(../oks001_FMC_VCG_0.7_ISO_10_vs_FMB_SAME.png, width=400, alt=oks001_FMC_VCG_0.7_ISO_10_vs_FMB_SAME)

  NOTE: this visualized distance on femur cartilage from the femur bone boundary can be used to find a cutoff value for generating a node set to tie nodes on the back surface of the femur cartilage to the rigid body femur.

Tissue Thickness

FEMUR CARTILAGE THICKNESS (UNSMOOTHED):

• femur cartilage, BACK SURFACE (REF; UNSMOOTHED) vs. femur cartilage, FRONT SURFACE (UNSMOOTHED)
• femur cartilage, FRONT SURFACE (REF; UNSMOOTHED) vs. femur cartilage, BACK SURFACE (UNSMOOTHED)

  • ImageLink(../oks001_FMC_UNSMOOTHED_BACK_vs_FMC_SAME_FRONT.png, width=400, alt=oks001_FMC_UNSMOOTHED_BACK_vs_FMC_SAME_FRONT.png)

    ImageLink(../oks001_FMC_UNSMOOTHED_FRONT_vs_FMC_SAME_BACK.png, width=400, alt=oks001_FMC_UNSMOOTHED_FRONT_vs_FMC_SAME_BACK.png)

FEMUR CARTILAGE THICKNESS (VCG smoothed, 0.7):

• femur cartilage, BACK SURFACE (REF; VCG smoothed, 0.7) vs. femur cartilage, FRONT SURFACE (VCG smoothed, 0.7)
• femur cartilage, FRONT SURFACE (REF; VCG smoothed, 0.7) vs. femur cartilage, BACK SURFACE (VCG smoothed, 0.7)

  • ImageLink(../oks001_FMC_VCG_0.7_BACK_vs_FMC_SAME_FRONT.png, width=400, alt=oks001_FMC_VCG_0.7_BACK_vs_FMC_SAME_FRONT)

    ImageLink(../oks001_FMC_VCG_0.7_FRONT_vs_FMC_SAME_BACK_INF.png, width=400, alt=oks001_FMC_VCG_0.7_FRONT_vs_FMC_SAME_BACK_INF)

FEMUR CARTILAGE THICKNESS (VCG smoothed, 0.7; ISO, 10):

• femur cartilage, BACK SURFACE (REF; VCG smoothed, 0.7; ISO, 10) vs. femur cartilage, FRONT SURFACE (VCG smoothed, 0.7; ISO, 10)
• femur cartilage, FRONT SURFACE (REF; VCG smoothed, 0.7; ISO, 10) vs. femur cartilage, BACK SURFACE (VCG smoothed, 0.7; ISO, 10)

  • ImageLink(../oks001_FMC_VCG_0.7_ISO_10_BACK_vs_FMC_SAME_FRONT.png, width=400, alt=oks001_FMC_VCG_0.7_ISO_10_BACK_vs_FMC_SAME_FRONT)

    ImageLink(../oks001_FMC_VCG_0.7_ISO_10_FRONT_vs_FMC_SAME_BACK_INF.png, width=400, alt=oks001_FMC_VCG_0.7_ISO_10_FRONT_vs_FMC_SAME_BACK_INF)

FEMUR CARTILAGE THICKNESS (LVTIT):

• femur cartilage, BACK SURFACE (REF; LVTIT) vs. femur cartilage, FRONT SURFACE (LVTIT)
• femur cartilage, FRONT SURFACE (REF; LVTIT) vs. femur cartilage, BACK SURFACE (LVTIT)

  • ImageLink(../oks001_FMC_LVTIT_BACK_vs_FMC_SAME_FRONT.png, width=400, alt=oks001_FMC_LVTIT_BACK_vs_FMC_SAME_FRONT.png)

    ImageLink(../oks001_FMC_LVTIT_FRONT_vs_FMC_SAME_BACK.png, width=400, alt=oks001_FMC_LVTIT_FRONT_vs_FMC_SAME_BACK.png)

NOTE: spurious distances (0.0 mm, which are known not to be correct) are present only in the FRONT SURFACE (REF) vs BACK SURFACE, despite similar relative normal directions between reference and measured surfaces!!!