1. UNIVERSAL MODEL DEVELOPMENT
OF THE HUMAN ANKLE FOOT REGION
FOR PLY PATTERN GENERATION
TO BE USED IN THE
MANUFACTURING OF PASSIVE DYNAMIC
ANKLE FOOT ORTHOTICS
Senior Thesis Defense for
Francis J. Fish

2. What are Composites
Composite are comprised of two or more separate
materials that, when combined, lead to improved
properties over the individual contributors.

3. Why Use Composites
Composites have high strength to weight ratio,
which far outperforms traditional materials.

4. Computer Aided Design Background
• The utilization of computer systems to aid in the
analysis, development, modification, and
optimization for design
• Software
• AutoCAD
• CATIA
• Creo
• Pro-E
• SolidWorks

5. Current AFOs
Ankle-foot orthoses (AFOs) are externally
applied medical devices
• Restore functionality to the lower extremity
• Limit range of motion
• Reduce pain during gait cycle

6. Current Approaches
Thermoplastic Forming
• Quickest/cheapest approach
• Limited design/tunability
3D Printing
• Requires full digitization of subject geometry
• Questionable fatigue performance
Thermosetting Composite
• Requires experienced orthotist to prescribe
• Very labor intensive
• Custom parts require unique tool for each part

7. Create Orthotic Program
DARPA Open Manufacturing Program
• Develop a novel, rapid manufacturing process for
composite AFOs
• Improve performance
• Reduce production times

8. Previous Attempt
Tool surface made of spring steel sheets
Attached at various points to push-pull Bowden cables
Cables attached to linear actuators outside oven
LabVIEW script controls linear displacements
Control
Cables
Oven
Linear Actuators and LabVIEW GUI

9. System Methodology
PRODUCTION
DRAWINGS
DXF files of the flat patterns are
generated to be sent for
manufacturing
PATIENT DATA
Weight, Height,
Disability %
(ankle stiffness)
GEOMTERICAL DATA
Foot length,
Foot breadth,
Knee height
AFO DESIGN
Selected concept
with side bands
to Manufacturing
AFO REQUIREMENTS
Segment-wise specifications for each of
the three directions obtained through
orthotist recommendation
Selected Ply
Stack
9
FOOT SIZING
Based on actual foot
dimensions, an appropriate
size is picked from the bin of
foot lengths and breadths
PLY LOOKUP
TABLE
From a set of pre-
populated size-based
solutions, appropriate
solution set is picked
up after necessary
modifications
DEVICE SPECIFICATIONS
Segment-wise specifications
control

10. Orthotic Production Method

11. Model Development
1. Anthropometric Data
2. CATIA Ergonomics Package
3. MakeHuman
4. Customized Set
 Fitting
 Scaling

12. Anthropometric Data
The subject’s foot length
and width are measured as
well as the subject’s height.
The height will is used
estimate the size of
MakeHuman model.
The foot dimensions are
used for selecting the
proper size foot model
based on military shoe size.

13. CATIA Ergonomics Package
Part of the CATIA
Ergonomics Package.
Creates a part files
By selecting:
 Gender
 Population
 Percentile
Can control the foot
dimensions

14. MakeHuman
Open Source software
Generates full body .stl
renderings
Fast and user friendly
By selecting:
 Gender
 Age
 Height
 Ethnicity
Can control the foot dimensions
Once weight reaches a normal
thresh-hold it no longer affects
the foot dimensions

15. Selection

16. Variable Control
• Attributes
• Height – Found to the main contributor to foot size
• Ethnicity – Secondary contributor
• Age – Held constant at 25
• Weight – Found not to be a variable
8
8.5
9
9.5
10
10.5
11
11.5
12
12.5
22 24 26 28 30 32
FootBreadthHorizontal(cm)
Foot Length (cm)
Foot Breadth Horizontal vs Foot Length
ANSUR
MakeHuman_Caucasian
MakeHuman_African

17. Fitting model to Data Set
Because MakeHuman creates the model based on overall height, it
is reasonable to compare the height to the measured foot
dimensions. From the different ethnic parameters a modeling set
was established to fit the ANSUR data.
8
9
10
11
12
13
158 168 178 188 198
Breadth(cm)
Height (cm)
Foot Breadth Horizontal
Foot Breadth
Horizontal
Caucasian
Foot Breadth
Horizontal ANSUR
Foot Breadth
African22
24
26
28
30
32
158 168 178 188
FootLength(cm)
Height (cm)
Foot Length
Foot Length
Caucasian
Foot Length
ANSUR
Foot Length African

18. Creating a Custom Model Set
In order to get the most precise representation of
the ANSUR data from the model set the ethnic
divisions were spliced together.
Shoe Size Height (in)
Foot Length
(in)
Foot Breadth
Horizontal (in)
Heel
Breadth (in)
Caucasian
No ADJ
6 63 9.44 3.56 2.55
African No
ADJ
6.5 64 9.57 3.63 2.61
African
+1in
7 65 9.81 3.67 2.65
7.5 66 9.96 3.73 2.67
8 67 10.08 3.78 2.71
8.5 68 10.33 3.84 2.75
9 69 10.46 3.94 2.78
9.5 69.6 10.51 3.94 2.82
10 70 10.67 3.99 2.84
10.5 72 10.95 4.11 2.91
11 73 11.05 4.14 2.96
11.5 74 11.27 4.34 2.98
12 75 11.42 4.39 3.05
Custom

19. Refinement
The separate scaling for the length and breadth
stem from there being narrow and wide shoe sizes.
22
24
26
28
30
32
34
150 170 190 210
Footlength(cm)
Height (cm)
Foot Length
Foot Length ANSUR
Adjusted MH Foot
7% Projected
Scaling
8
9
10
11
12
13
14
158 168 178 188 198
FootBreadth(cm)
Height (cm)
Foot Breadth
Foot Breadth
ANSUR
Adjusted MH Foot
18% Projected
Scaling

20. Validation
1. Casting
2. Scanning
3. Digital Model
Utility
4. Cross-sectioning
5. Point Cloud
Analysis
CATIA
Space
Analysis
CAD Model
Scanned Foot

21. Preparation
Patient
removes
shoe and sits
in a chair with
the back
braced.
Flexible
tubing is cut
and the tip is
sliced off at
roughly a 30
degree angle.
A bag is
placed over
the patient’s
leg and taped
so not to be
loose.
The flexible
tubing is then
applied to the
top of the
patient’s foot
and held in
position with
tape.
The casting
sock is
opened and
scrunched
until thumbs
touch toe
region of the
sock.
The sock is
plunged in
water for ten
seconds.
The sock is
then put on
the patient
and hand
coated with
water.

22. Casting
The patient
then stands
on a
cushioned
surface.
The cast
should be
mostly dry
before the
patient is
allowed to sit
with the cast
elevated.
The cast is then
cut along the
tubing with a
cast saw.
The cast is then
cut along the
tubing with a
cast saw. The
cast is then
wrapped with
tape to prevent
the plaster from
leaking.
Plaster is then
poured into the
cast and
allowed to
harden.

23. Scanning
Scans of the casts were
preformed using the
GoScan at ATTL to create
a point cloud to compare
against the models.

24. Digital Model Utility Analysis
Red- Model
Green- Scan
Yellow- Both within
.201cm of each other
7% scaling of the length
and 18% scaling of the
width was used.

25. Cross-section Analysis
Left Center Right Heel Ball
1.75 .97 1.45 .94 .89

26. Point Cloud Analysis
The two surfaces were
aligned then points were
placed on the model.
Those points were then
projected normal to the
surface onto the scanned
surface. The distance
between the points was
then measured. Average
was 0.490 centimeters.

27. Coverage
Length
• σ = .22 in or 5.58%
• The standard model will provide coverage to
50% of the population that wears a size 10
shoe.
• A 7% scaling covers 88% of the population.
• Larger than a 7% scaled model should be
addressed by use of the ply the next size up.
• Because there is a 2% size increase the size
10.5 ply covers 95%.
Breadth
• σ = .35 in or 8.66%
• The standard model will provide coverage to
50% of the population that wears a size 10
shoe.
• A 18% scaling covers 98.7% of the
population.
• Larger than a 18% scaled model should be
addressed by use of the ply the next size up.
• Because there is a 2% size increase the size
10.5 ply covers the remaining.
Length & Breadth Coverage for a Size 10 AFO

28. Path Forward
1. Single leg model
2. CFI implementation

29. Single Leg Model
Single leg model is
being used for
generating the plies
for the cuff as well
as for the ankle foot
region.

30. Center for the Intrepid
Will be transferring
the system to the
Center for the Intrepid
where it will allow
disabled veterans to
walk again without
pain.

31. Summary
• Create a 3D CAD model of a human foot
• Based on the ANSUR Data
• Establish points of measurement interest from
the model with a defined reference origin
• Scaled the model to allow for 1st-99th percentile of
wears
• By using shoe size or half size larger
• Will be helping disabled veterans walk again

32. Closing Remarks
Special thanks to the Center for Composite
Materials at the University of Delaware for the
opportunity to work on this project for the past four
years and for providing materials and personal to
make this program successful. This program was
also assisted by the professionals at the Application
& Technology Transfer Laboratory for their
contribution of resources throughout the program.

33. Acknowledgements
Research was sponsored by the Defense Advanced Research
Projects Agency (DARPA) and was accomplished under the Army
Research Laboratory Cooperative Agreement Number W911NF07-2-
0026. The views and conclusions contained in this document are
those of the authors and should not be interpreted as representing
the official policies, either expressed or implied, of the Defense
Advanced Research Projects Agency, the Army Research
Laboratory or the U.S. Government. The U.S. Government is
authorized to reproduce and distribute reprints for Government
purposes notwithstanding any copyright notation heron.

34. Questions