Post on 08-Oct-2020
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 1
Air Muscle Artificial Limb – Second Generation
P09023
Detailed Design Review
Multidisciplinary Senior Design I
Rochester Institute of Technology
Friday, October 24, 2008
“Design and build an artificial limb capable of moving in all directions of freedom of a human hand”
https://edge.rit.edu/content/P09023/public/Home
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 2
Table of Contents Project Summary ........................................................................................................................................... 3
Customer Needs & Specifications ................................................................................................................. 4
Design Metrics versus Customer Needs ....................................................................................................... 5
Team Structure ............................................................................................................................................. 6
Faculty, Advisors, and Customer ................................................................................................................... 7
Human Hand Anatomy .................................................................................................................................. 8
Air Muscles .................................................................................................................................................... 9
Air Muscle Data ........................................................................................................................................... 10
Mesh Materials ........................................................................................................................................... 13
Spring and Air Muscle Sizing ....................................................................................................................... 14
Overall Concept ........................................................................................................................................... 15
Hand Design ................................................................................................................................................ 16
Controls Design ........................................................................................................................................... 17
Controls Algorithm ...................................................................................................................................... 18
Prototype .................................................................................................................................................... 20
Reactions to the Concept Design Review ................................................................................................... 21
Customer Feedback .................................................................................................................................... 22
Preliminary Schedule .................................................................................................................................. 23
Appendix A – Detailed Design Risk and Progress Assessment .................................................................... 24
Appendix B – Bill of Materials ..................................................................................................................... 27
Appendix C – Drawings ............................................................................................................................... 28
Hand Design ............................................................................................................................................ 28
Finger Design ........................................................................................................................................... 29
Joint Design ............................................................................................................................................. 30
Disk Design .............................................................................................................................................. 31
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 3
Project Summary
This is a second generation project aimed at developing a scalable air-muscle actuated robotic
hand. The first generation of this project created three fingers with complete range of motion but did
not complete the pinky, the thumb, or motion of the palm. Eventually the hand could be scaled down
for microsurgery or scaled up for deep sea maintenance applications. The primary objective of this
project is to improve upon the first generation of the project through the design and build of an artificial
limb capable of moving in all directions of freedom of a human hand. The mechanical design and the
controls system should accurately imitate motions of the human hand, and the design should be easily
repeatable, robust, and easy to use. At the end of this project, the customer will be presented with a
hand meeting all of the set criteria and an optimized control algorithm.
Objectives:
Gain understanding of work from the first generation
Make the current design more robust
Update the controls scheme
Determine joint/muscle attachment methods
Implement design
Expected Benefits:
Reinforce the bioengineering program at RIT
Teaching and prospective student recruitment tool
Platform for future senior design projects
Benefits in prosthetics field
Possibility for remote surgery
Potential Problems:
See Appendix A – Detailed Design Risk and Progress Assessment
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 4
Customer Needs & Specifications
Need Description Importance
Air Muscle Safety Air muscles cannot explode 1
Cable Safety Cables cannot break 1
Controls Safety Control system exhibits safe motion 1
Follow Regulations Project follows all RIT rules 1
Distal Interphalangeal Joint Motion Range of Motion of Distal Interphalangeal Joint 1
Proximal Interphalangeal Joint Motion Range of Motion of Proximal Interphalangeal Joint 1
Metacarpophalangeal Joint Motion Range of Motion of Metacarpophalangeal Joint 1
Robust Hand cannot break 2
Scalable Project must be scalable for future generations 4
Mechanical Optimization Improvement from current system 2
Software Optimization Improvement from current system 2
Ease of Use Must be easily operated 4
*Needs ranked on a scale from 1 to 5 with 1 being the most important
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 5
Design Metrics versus Customer Needs
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 6
Team Structure
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 7
Faculty, Advisors, and Customer
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 8
Human Hand Anatomy
Figure 1: Hand Anatomy
Figure 2: Joint Directions of Freedom
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 9
Air Muscles
Figure 3: Air Muscles
Air muscles consist of a flexible, expandable tube covered in a separate meshed tube.
The two tubes are clamped off at one end, and air pressure is allowed to enter at the other end.
When the tube is pressurized, it expands, and that forces the mesh to expand.
Since the surface area of the mesh must be conserved, the length of the tubes decreases.
This air muscle contraction is an attempt to mirror biological muscle contraction and control.
P08023 performed extensive air muscle research which we will utilize and work forward from. We will
be confirming their test results for our design purposes, but we will not be re-evaluating air muscles or
looking into any alternatives for this project.
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 10
Air Muscle Data
The charts below were developed by the previous senior design teams. The first four charts
testing two different lengths of air muscles as well as two different materials. The PET mesh is
Polyethylene Terepthalate.
Figure 4: 2.5 Inch PET Mesh Change in Length
Figure 5: 2.5 Inch Mylar Mesh Change in Length
0
0.1
0.2
0.3
0.4
0.5
0.6
0 10 20 30 40 50 60 70
Co
ntr
acti
on
(in
che
s)
Pressure (psig)
2.5 inch PET Mesh - 1/8 inch Tubing
0
0.1
0.2
0.3
0.4
0.5
0.6
0 10 20 30 40 50 60 70
Co
ntr
acti
on
(in
che
s)
Pressure (psig)
2.5 inch Mylar Mesh - 1/8 inch Tubing
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 11
Figure 6: 5 Inch PET Mesh Change in Length
Figure 7: 5 Inch Mylar Mesh Change in Length
From the charts above, it is apparent that there is a significant difference
between PET mesh and mylar. More testing must be done to validate these tests
for our application.
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 10 20 30 40 50 60 70
Co
ntr
acti
on
(in
che
s)
Pressure (psig)
5 inch PET Mesh - 1/8 inch Tubing
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 10 20 30 40 50 60 70
Co
ntr
acti
on
(in
che
s)
Pressure (psig)
5 inch Mylar Mesh - 1/8 inch Tubing
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 12
The chart below is from team P08024. They tested several air muscles of
different lengths. This chart shows that longer air muscles do contract more, and
over the region of tube lengths, the maximum contraction seems linear. Again,
more testing must be done to validate these tests.
Figure 8: P09024 Air Muscle Data
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2 3 4 5 6 7 8
Delt
a L
en
gth
(in
)
Original Tube Length (in)
Tube Length vs Maximum Delta
Muscle A
Muscle B
Muscle C
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 13
Mesh Materials
PET Polyethylene Terephthalate
Material Specifications
Strength & Abrasion
Tensile Strength PSI 85000
Abrasion Resistance H
Tenacity gms/denier 4.5
Typical Elongation
Break 15
3g/denier 5
Specific Gravity 1.38
Metallic Mylar® is braided from .010" monofilament made from PolyEthylene Terephthalate, with a
continuous operating temperature of -103°F to 257°F. Its melt temperature is 446°F and is offered in 2
dramatic colors: Gold and Silver. Mylar sleeving is a mildly conductive polyester film that helps with
electrical insulation and shielding. It is also compliant with European Union's Restrictions on the use of
Hazardous Substances (RoHS) Directive.
Flexo Chrome (CH) Flexo Chrom is engineered by braiding heavy gauge 5 mil metallized polyester film (Mylar®) in combination with our clear polyethylene terepthalate (PET), we've produced a tough, durable and attractive solution for a wide range of applications, especially cosmetic ones. Even though it is very similar to our Mylar® product, it is heavier and has a much better abrasion resistance. The metallized Mylar® component is conductive, allowing Flexo Chrome to be used in shielding applications, as well as applications where the temperature exceeds 400° F.
This strong and attractive product is both practical in electronic applications and decorative on the wires and hoses of high end show cars and motorcycles. Flexo Chrome is more durable than our Mylar® and more abrasion resistant, but they basically look the same.
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 14
Spring and Air Muscle Sizing
Springs will be used to pull the fingers straight. The spring constants need to be determined as
well as the air muscle forces. The springs will be sized after conducting a force analysis on the hand. Jim
Breunig and Alex Bird have been working on the force analysis.
Each phalange is separated, and a free body diagram is drawn on each phalange. The forces in
the vertical direction (using global coordinates) are then summed, and the sum must be greater than
zero. This will allow for acceleration in the vertical direction, allowing the fingers to straighten. This
method produces four equations, and eight unknowns.
The phalanges are then divided up differently. The distal phalange and middle phalange are
modeled as 1 body. Then the distal, middle, and proximal phalanges are modeled as one body. The
distal, middle, proximal phalanges and metacarpal bones are then modeled as 1 body. The middle and
proximal phalanges are also modeled as one body. This produces four more equations, and no more
unknowns.
The two sets of equations can then be solved for the tension force. This is still being solved.
Matlab will be used so that it can be implemented by future senior design teams. If the design changes,
the user would change the mass and change the geometry dimensions using matlab.
This analysis will also be used to determine the force required for the air muscle. The air muscle
must be able to overcome the spring force. The spring and air muscle deflection can be calculated using
simple geometry. With the force and deflection, the spring constants can be determined for the springs.
This analysis should be completed by the end of week 9.
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 15
Overall Concept
Figure 9: Overall Flow Chart
*See Appendix B for Bill of Materials, Appendix C for Detailed Design Diagrams, and Appendix D for Detailed Controls
Schematics
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 16
Hand Design
One of the problems from both P08023 and P08024 was the manufacturing of the hand was difficult and time consuming. One of the main criteria for this project is that it must be easy for someone else to replicate, and in order to meet this criteria, the hand’s design incorporates as many off-the-shelf parts as possible.
Figure 18: Full Hand Assembly
*See Appendix C for more detailed drawings about the hand assembly and individual components
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 17
Controls Design
“VACCUUM”
PLENUM
ATMOSPHERE
MANIFOLDMANIFOLD
MANIFOLD
MANIFOLD
MANIFOLD
MANIFOLD
MANIFOLD
MANIFOLD
AIR MUSCLES
DIGITAL
PRESSURE
GAUGE
ELECTROMECHANICAL SYSTEM
P09023: ARTIFICIAL AIR MUSCLE LIMB
MECHANICAL
PRESSURE
REGULATORS
SOLENOID
ON/OFF
VALVES
WALL
PLENUM
WALL
SUPPLY
DIGITAL
PRESSURE
GAUGE
Figure 10: Controls Design
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 18
Controls Algorithm
USB DAQ
1
USB DAQ
2
USB DAQ
3
RELAY BOARD
1
RELAY BOARD
2
RELAY BOARD
3
RELAY BOARD
4
p1
p2
p3
[23,1]
E
[23,1]
R
r1
r2
r3
~
~
~
r4~
~
~
~
Ri = Ri-1
CONTROLS ALGORITHM
IF ERROR IS POSITIVE
TOO MUCH AIR IN MUSCLE
BEGIN RELEASING AIR
IF ERROR IS ZERO
JUST ENOUGH AIR IN MUSCLE
STOP ANY ACTION
IF ERROR IS NEGATIVE
NOT ENOUGH AIR IN MUSCLE
BEGIN FILLING AIR
1
-1
-sgn(φi+τ)
φiττ
[23,1]
P
[23,1]
D
P
D
E
~
[46,1]
R
R
~R
Concatenated Vector of Potentials Read from DAQs 1200 Times Per Second.
User Input Vector Relating to ASL Letter Predetermined Finger Positions (Potentials)
Error Vector, Pure Difference
Thresholded Error Vector (Result), Still Only Related to Potentiometers
Adjusted Resultant Vector Transformed to Value for All Valves, Not Just At Potentiometers
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 19
time
[ms]
Potential
[V]
αANGLE/POTENTIAL
FACTOR
φfinal
φstop
φopen
φ0
time
[ms]
Potential[V]
αi4φfinal
φstop
φopen
φ0
αi3αi2
αi1
EXPERIMENT FOR PRESSUREi
αi = Average(αij),
A
jφf3φs3φf2
φs2φf1φs1
tclose tstop
1
-1
-sgn(φi+τ)
φiττ
τ = f(α)
THRESHOLDING
α = f(PRESSURE)
αi = CONSTANT | PRESSUREi
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 20
Prototype
The book Robots Androids and Animatrons by John Lovine details how what the air muscles are, how to
make them, and how to assemble an actual robotic hand using the “Amazing Arm” toy. While the
resulting product clearly does not meet all criteria for this project, it is similar enough to the chosen
design that it will be immensely helpful in proving the design concepts set forth thus far. This will also
give our team practice in air muscle use and construction, while providing a quick and basic
understanding of our system’s structure and function as we finalize our design and testing.
Figure 11: Awesome Arm Prototype
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 21
Reactions to the Concept Design Review
The concept design review held at 8:00 am on Friday, October 3, 2008, alerted the team to many
potential concerns. Because of the progress the team had made up until that point, the concept design
review quickly morphed into a preliminary design review, and many of the concerns brought up there
have since been addressed or identified in detail as suggested.
Concern Countermeasure
The team had no way of benchmarking because
preliminary risk assessment does not contain
enough quantitative factors.
The team created the "Detailed Design Risk and
Progress Assessment" document, which includes
many more quantitative factors.
Air muscles proved to be unreliable in the last
iteration of the project, so pairing them does not
seem like the best idea.
A spring will be paired with each air muscle as a
passive way of returning the fingers to their neutral
positions, if viable.
The springs may not be able to return all parts of the
fingers to the neutral position without some help.
Testing will show which springs are not capable, and
those springs will be replaced with air muscles. The
design will have room for all air muscles.
Air muscle discharge is not linear or predictable.
A vacuum will be attached to a plenum at the exit
for the air muscles and extensive testing will be
done to identify the system response as much as
possible.
The team did not seem to have much data from the
first generation of the project.
The team located all old files and had Chappy sort
through them. The team will be confirming the old
data through testing.
The team seemed too focused on the speed of the
muscle's reactions and not on anatomical accuracy.
The team consulted with the customer and has
decided that speed is not as important as
anatomical accuracy.
The mechanical design presented at the concept
design review seemed hard to manufacture.
The design has been revamped using mostly off-the-
shelf components.
The team seemed to lack knowledge of how a
human hand really works.
The team visited Dr. Doolittle in the cadaver lab and
has started a free body diagram.
Time delays in the control system seemed imminent,
unpredictable, and uncontrollable.
The team decided that the hand will always start at
pre-defined and tested neutral position. All test data
will therefore remain relevant throughout
operation.
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 22
Customer Feedback
Thus far the customer, Dr. Lamkin-Kennard, has been pleased with the team’s concepts and progress.
Degrees of Freedom
The main focus of this project is to maintain the same directions of freedom of this human hand.
Dr. Lamkin-Kennard has been keeping us on track throughout the project so that we can be as accurate
as possible.
Modular Mechanical Design
Dr. Lamkin-Kennard likes the idea of having off the shelf parts in the design. She said that a
previous team of hers spent a lot of time machining parts. By using a modular, off the shelf design, parts
can be swapped out quickly, the design can act as a platform, and overall mechanical assembly is faster
and easier.
Controls Design
The controls team has held meetings with Dr. Lamkin-Kennard. We showed her the flow charts
for the controls scheme, and she is very happy with the direction that we are going.
Platform Design
Dr. Lamkin-Kennard has helped the team maintain focus throughout the project. Every major
design decision has been discussed with Dr. Lamkin-Kennard. One aspect of this design is the need for it
to act as a platform for future senior design teams. This design should be able to be built on and
improved for future generations of the project.
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 23
Preliminary Schedule
Item Completed by Date
FBD Analysis Jim & Alex 10/24/2008
Valve Test Program Eva 10/27/2008
Order Hand Parts Design Team 10/31/2008
Valve Testing Eva 10/31/2008
Order control system parts Controls Team 11/05/2008
Air Muscle Test Rig Eva 11/07/2008
Hand Completely Assembled Design Team 12/19/2008
P08023 Air Muscle Test Validation Controls Team 12/19/2008
Air Muscle Fill Time Testing Controls Team 12/19/2008
Order Air Muscle Supplies Controls Team 12/19/2008
Air Muscle Production Controls Team 01/09/2009
Air Muscle Attachment Controls Team 01/09/2009
Spring Selection Eva 01/16/2009
Finger Spelling Program Tommy 01/16/2008
Spring Strength & Capability Testing Controls Team 01/23/2009
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 24
Appendix A – Detailed Design Risk and Progress Assessment
*Highlighted rows indicate that a countermeasure has been chosen
Problem Countermeasure Quantification Category
1
The cables used for tendons stretched
through regular use and frequently need
to be replaced
The fishing line used could be pre-
stretched prior to installation on the
hand
Cable cannot stretch more than .25”
once installed Maintenance
1
The cables used for tendons stretched
through regular use and frequently need
to be replaced
A different material could be selected
for the cable
Cable cannot stretch more than .25”
once installed Maintenance
2 Some air muscles exploded because the
clamps were not strong enough
Use hose clamps instead of “crimpable”
clamps
0 of the air muscles can explode once
installed on the hand
Air Muscle
Quality Control
2 Some air muscles exploded because the
clamps were not strong enough
Perform a quality control check on all air
muscles prior to installation
0 of the air muscles can explode once
installed on the hand
Air Muscle
Quality Control
3
Passive finger position control needs to
be replaced frequently. Rubber bands
dry-rot very quickly and rubber tape
needs to be replaced every couple of
weeks.
Use air muscles to control the fingers'
movement back to the hand's neutral
position
Hand should not need to be serviced
more than 1 time per month Maintenance
3
Passive finger position control needs to
be replaced frequently. Rubber bands
dry-rot very quickly and rubber tape
needs to be replaced every couple of
weeks.
Use springs to pull the fingers back to
the hand's neutral position. If the air
muscle can be controlled at partial fill
levels, only one muscle is needed to pull
the finger down.
Hand should not need to be serviced
more than 1 time per month Maintenance
4 Air muscles leak, and it is difficult to
keep them filled at a constant volume
Use barbed fittings at the ends of the air
muscles instead of the push-connect
fittings
Air muscles cannot cause fingers to
move more than 10 degrees away from
the target position
Hand
Performance
4 Air muscles leak, and it is difficult to
keep them filled at a constant volume
Vent the exhaust valves to a vacuum
chamber to control the air muscle
deflation
Air muscles cannot cause fingers to
move more than 10 degrees away from
the target position
Hand
Performance
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 25
4 Air muscles leak, and it is difficult to
keep them filled at a constant volume
Use softer material for the hoses, which
will conform to the fitting rather than
just sitting on top of the stem
Air muscles cannot cause fingers to
move more than 10 degrees away from
the target position
Hand
Performance
5 Having a large number of air muscles
will be bulky and difficult to package
Reduce the number of air muscles
required
Use springs to pull the fingers back to
the hand's neutral position. If the air
muscle can be controlled at partial fill
levels, only one muscle is needed to pull
the finger down. This will reduce the
number of required air muscles to 23
Aesthetics
5 Having a large number of air muscles
will be bulky and difficult to package
Design the packaging around the size of
the final assembly Aesthetics
5 Having a large number of air muscles
will be bulky and difficult to package Package the assembly into a mannequin
If we go this route, we need to define
the size of the mannequin Aesthetics
6 The previous hands do not have any
motion in the palm
The design team will design a system of
air muscles to move the palm
*We need to find out if there is a chart
documenting palm motion capabilties
Anatomical
Accuracy
7
The fingers on previous hands are not
able to accurately represent the
potential rotation in a human finger
Chris came up with a new concept for
the design of the fingers
The fingers must be able to move as
specified in Jim's chart
Anatomical
Accuracy
7
The fingers on previous hands are not
able to accurately represent the
potential rotation in a human finger
Use ball and socket joints instead of pin
connections
The fingers must be able to move as
specified in Jim's chart
Anatomical
Accuracy
7
The fingers on previous hands are not
able to accurately represent the
potential rotation in a human finger
Use a pre-made skeleton of the human
hand
The fingers must be able to move as
specified in Jim's chart
Anatomical
Accuracy
8 The cables may bind up if they have to
wind through the fingers
Attach the cables to the outside of the
fingers just like tendons connect to bone
in an actual hand
The fingers must be able to move as
specified in Jim's chart
Anatomical
Accuracy
9
The fingers in Chris's design might be
too heavy for the air muscles to move
them
Make the fingers hollow The fingers must be able to move as
specified in Jim's chart
Anatomical
Accuracy
10
The fingers in Chris's design might not
be able to accommodate for the cables
running through them
Make the fingers hollow The cables can never bind up Manufacturability
10
The fingers in Chris's design might not
be able to accommodate for the cables
running through them
Attach the cables to the outside of the
fingers just like tendons connect to bone
in an actual hand
The cables can never bind up Manufacturability
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 26
11 Springs may not be able to return all the
fingers to their neutral positions
Test and figure out if some portions of
the fingers need to have air muscle
assistance for their return to the neutral
position
The fingers must be able to move as
specified in Jim's chart
Anatomical
Accuracy
12 The air muscles are sometimes slow to
fill, causing a delay to finger motion
Use valves with a larger minimum orifice
size
The fingers must be able to move as
specified in Jim's chart
Anatomical
Accuracy
13 The larger the valves are, the more
expensive they get
Prove that motion is possible with
largest valves allowed by budget
Valve cost must be less than $20 per
valve Cost
13 The larger the valves are, the more
expensive they get
Allow for future generations to hook up
larger valves to our design
Valve cost must be less than $20 per
valve Cost
14 Current control system is ineffective,
complex, and difficult to operate
Program a very reliable, easy to use
interface Controls
15 Current control system is not easily
modifiable for future generations
Create a program for the control system
which is easily modifiable by future
generations of this project
Controls
15 Current control system is not easily
modifiable for future generations
Clearly document how and why
everything with the program was done Controls
16
Files from the past generation of this
project are not easily decipherable and
not easily accessed
Clearly document how and why
everything was done
Future
Generations
16
Files from the past generation of this
project are not easily decipherable and
not easily accessed
Leave Dr. Lamkin-Kennard all of our lab
books and a clearly organized CD with all
of our files
Future
Generations
17
Current hand layout is messy and not
aesthetically pleasing for
demonstrations
Aesthetics
18 Hand must be easy to replicate
We must leave behind lots of
documented drawings and notes about
the design
It cannot take more than a week for
someone to replicate our hand Manufacturability
18 Hand must be easy to replicate We will make lots of annotated drawings It cannot take more than a week for
someone to replicate our hand Manufacturability
19 USB relay boards might not like being
chained together
Test to figure out what the reaction is
for the USB relay boards being chained
together?
Either the boards work or they don't Controls
19 USB relay boards might not like being
chained together Mix PCI cards with the needed relays Either the boards work or they don't Controls
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 27
Appendix B – Bill of Materials
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 28
Appendix C – Drawings
Hand Design
Figure 12: Full Hand Assembly
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 29
Finger Design
Figure 13: Pinky Finger Assembly
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 30
Joint Design
Figure 15: DIP and PIP Female Joint Figure 14: DIP and PIP Male Joint Figure 22: Universal Joint
P09023: Air Muscle Artificial Limb Design Review October 24, 2008
Page 31
Disk Design
Figure 23: Disk