creating and simulating skeletal muscle from the visible human data set
DESCRIPTION
Creating and Simulating Skeletal Muscle from the Visible Human Data Set. Authors: Joseph Teran Eftychios Sifakis Silvia S. Blemker Victor Ng-Thow-Hing Cynthia Lau Ronald Fedkiw. Presented By : Federico Bermudez. PROBLEM. - PowerPoint PPT PresentationTRANSCRIPT
MSIM 842 VISUALIZATION II INSTRUCTOR: JESSICA R.
CROUCH
Creating and Simulating Skeletal Muscle from the Visible Human Data Set
Authors:•Joseph Teran• Eftychios Sifakis• Silvia S. Blemker•Victor Ng-Thow-Hing•Cynthia Lau• Ronald Fedkiw
Presented By: Federico Bermudez
21 Mar 2007 1
PROBLEM
• Create anatomically realistic simulations of the human musculoskeletal system.
• Create visually accurate simulations of the interactions between muscles and bones.
• This paper present a method for creating such simulations using the visible human data set.
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
2
MOTIVATION
• Anatomically and visually accurate simulations of the musculoskeletal system are critical in:
• biomechanics• biomedical engineering• surgery simulation• computer graphics
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
3
APPROACH
PRIOR & RELATED WORK• Prior work
– Simple less accurate models encompassing many muscles.– Complex models that only simulate a few number of muscles.– These models are less visually accurate.
• Related work– Seems to be concentrated on the use of the Finite Element Method
(FEM), the Finite Volume Method (FVM), and tetrahedral meshes
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
4
APPROACH
MODEL CREATIONThe Visible Human Data Set
Run by the U.S. National Library Of MedicineConsists of MRI, CT, and anatomical Images
Male data set released in Nov 1994– Joseph Paul Jernigan (38-year-old Texas murderer executed 5 Aug 1993) – cadaver was frozen and cut (1871 axial slices at 1 millimeter intervals)– Photographed and digitized – 15 GB
Female data set released in Nov 1995– 59-year-old Maryland housewife who died from a heart attack– cadaver was frozen and cut (5189 axial slices at 0.33 millimeter intervals)– Photographed and digitized – 40 GB
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
5
APPROACH
MODEL CREATIONThe Visible Human Data Set
Problems with the data set– Male brain slightly swollen by the freezing process– Small blood vessels were collapsed by the freezing process – His inner ear ossicles were lost during preparation
Site: http://www.nlm.nih.gov/research/visible/
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
6
APPROACH
MODEL CREATIONThe Visible Human Data Set
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
7
CT Scan Color Cryosections
Thorax subset
APPROACH
MODEL CREATIONThe Visible Human Data Set
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
8
APPROACH
MODEL CREATIONRepairing Errors
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
9
APPROACH
MODEL CREATIONMeshing Bone and Muscle
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
10
APPROACH
MODEL CREATIONMeshing Bone and Muscle
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
11
APPROACH
MODEL CREATIONTendon and Bone Attachment Designation
assign tendon, bone attachments, and muscle properties to sections of the mesh
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
12
APPROACH
MODEL CREATIONB-Spline Fiber Representation
Use B-spline solids to assign fiber directions to individual tetrahedrons.
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
13
APPROACH
MODEL CREATIONSkeletal Motion
– Contraction of the muscles drives the motion of bones.– In this model, the skeleton drives the motion and contraction of muscles, tendons, and
surrounding tissue.– A realistic model involves intricate knowledge of bones and joints interaction , often
requiring multiple degrees of freedom to describe their movements.– The Obstacle-set Method was used to modeled the paths of the muscles.– Cylinders and spheres were used to compute muscles and bones collisions.
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
14
APPROACH
MODEL CREATIONSkeletal Motion
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
15
APPROACH
MODEL CREATIONSkeletal Motion
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
16
APPROACH
FINITE VOLUME METHOD• FVM more intuitive than the finite element method (FEM)• FVM reduces the stress inside a tetrahedron to a simple multidimensional
force pushing on each face.• The inverting FVM algorithm developed from the FVM facilitates the
simulation of objects that must undergo deformation and return to their original or partial shape.
• Video – 01 & 02 show simulations using the inverting FVM.
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
17
APPROACH
CONSTITUTIVE MODEL FOR MUSCLE• An strain energy function is used to model the
contracting of the muscles.• Model includes only what is necessary to produce
bulk length-based contraction along the muscle fiber direction.
• As we will see on the video, the bulk deformations of the muscles are very subtle.
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
18
APPROACH
EMBEDDING FRAMEWORK• The complete model of the upper limb consist of over 30 muscles
constructed with over 10 million tetrahedra.• A dynamic Free Form Deformation embedding scheme was used to
reduce the computational cost.• The BCC grid size used resulted in a tenfold reduction in the size of the
simulation mesh.• Time step restriction for stability was relaxed by a factor of 25.• These factors enabled the full finite element simulation at rates of 4
minutes per frame on a Xeon 3.06 GHz CPU.• A nonmanifold simulation mesh is obtained by collapsing equivalent
vertices.
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
19
APPROACH
FASCIA AND CONNECTIVE TISSUES• Muscles are enclosed in a network of connective tissue that keep them in
close contact during motion.• Model enforces a state of frictionless contact between the muscles.• In essence the intersection between different muscles is determined and
recalculated each time during motion in order to maintain the muscle tissues in close contact.
• Video – 03 shows the simulation without fascia.
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
20
APPROACH
SIMULATING SKELETAL MUSCLE
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
21
Run videos1. Video – 04 - Frontal View2. Video – 05 - Side View
Evaluation
• The construction of the muscles, tendons, and bones seems to be correct.
• I think the simulation shows the compression and relaxation if the muscles visually accurate.
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
22
Conclusion & Future Work
• The authors successfully created a visually accurate simulation of the interaction of the bones, muscle, and underlying tissue of the human right upper limb.
• Current hardware and algorithm technology still too complex to achieve whole body simulations.
• Create subject-specific models with MRI and CT data.• Morph VHP data set to match specific subject or body type
using anatomical landmarks.
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
23
Questions
• How much more complex would be to simulate the whole body.
• Can this technique be use to simulate the involuntary muscles such the hear heart?
• Can this technique be applied to the design of artificial limbs.
21 Mar 2007MSIM 842 VISUALIZATION II
INSTRUCTOR: JESSICA R. CROUCH
24