Introduction Fall 2014 Earliest amputation recorded by Herodotus Greek historian 480 BC Persian soldier Hegesistratus arrested by Spartans facing torture and execution one foot in stocks cut off foot to escape later obtained a prosthetic wooden foot ID: 164021
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Slide1
Prosthesis Design and Control
Introduction
Fall 2014Slide2
Earliest amputation recorded by Herodotus, Greek historian,
480 BC
Persian soldier Hegesistratus arrested by Spartans, facing torture and execution, one foot in stocks, cut off foot to escape, later obtained a prosthetic (wooden) foot
2
Stump, or residual limb
www.vitalitymedical.comSlide3
Disarticulation: Amputation between bone surfaces
3
www.cdha.nshealth.ca
2%
33%
1%
54%
3%
Upper limb amputations: 7%Slide4
Causes of amputation
Accident – 23%
Disease or infection – 74%Cancer – 2%Vascular (circulatory) – 54%Diabetes – 70%Tripled between 1980 and 2005
Diabetic survival rate is improving1/3 of adults diabetic by 2050Birth defect – 3%Paralysis – less than 1%
4Slide5
As of 2014:
2 million people with limb loss in the United States
185,000 amputations in the United States each yearIn 2009, hospital costs associated with amputation totaled more than $8.3 billionAfrican‐Americans are four times more likely to have an amputation than white AmericansNearly half of those who have an amputation due to vascular disease die within 5 years
Diabetics who have a leg amputation have a 55% of a second amputation within 3 yearswww.amputee-coalition.org
5Slide6
Amputations
by age
Below 10 years old: 3%11-20 years old: 7%21-30 years old: 7%31-40 years old: 7%41-50 years old: 9%51-60 years old: 18%61-70 years old: 28%
71-80 years old: 17%Over 80 years old: 4%A Primer on Limb Prosthetics, p. 9
6Slide7
7
Corset-style
interface, pre-1960shttp://www.studyblue.com/notes/note/n/rehab-prosthortho-pictures/deck/6884210
Patellar-tendon-bearing socket, introduced in the 1960sSlide8
8
Silesian bandage
http
://
oandplibrary.com(Silesia is a region in Poland)
Total
elastic suspension
belt
http://www.ortho-europe.com/prosthetics/Liners
Pelvic belt
amhs.org.au/Virtual Museum/Surgery/orthopedics/Limb-prosthesesSlide9
Socket
Knee
ShankAnkle
Foot
9
www.ottobockus.com
Mechanical interfaces between leg components are standard, which provides a “plug and play” prosthesis.
Socket interfaces
Liner / lock – low activity
Suction – medium activity
Vacuum – high activitySlide10
Gait Cycle: 2 steps = 1 stride
10
Heel strike
Heel strike
www.jaaos.org/content/15/2/107/F1.large.jpg
12%
50%Slide11
Lower limb amputee activity levels
Level 0
Does not have the ability or potential to ambulate safely and a prosthesis does not enhance their quality of life or mobility.Level 1
The ability or potential to use a prosthesis for transfers or ambulation on level surfaces at fixed pace. This prosthesis is typical for the household ambulator.
Level 2The ability or potential for ambulation with the ability to traverse low-level environmental barriers such as curbs, stairs, or uneven surfaces. This prosthesis is typical
for the limited community ambulator.Level 3The ability or potential for ambulation with variable pace, with the ability to traverse most environmental barriers
while participating in activities of daily living that require prosthetic use beyond simple locomotion.Level 4The ability or potential for prosthetic ambulation that exceeds basic ambulation skills,
exhibiting
high impact, stress, or energy levels. This prosthesis is typical of the
child
or active adult functioning in the community
.
11
www.health.alberta.ca/documents/AADL-Manual-P-Products.pdfSlide12
Prosthetic Feet
More than 50 models available today
Some design for special activitiesFeet with no hinged parts: Low activity level
12
www.heritage-medical.com/foot-prosthetics
www.willowwoodco.com/products-and-services/feet/low-activity/sach
Solid ankle cushioned heel (SACH)
Elastic keel: more flexibleSlide13
13
http://www.ossur.com/prosthetic-solutions/products/feet/feet/flex-foot-assure
Flex foot
http://www.telegraph.co.uk
Oscar
Pistorius
, 2012 South African Olympic sprinter
http://www.dailymail.co.ukSlide14
Articulated Prosthetic Feet
14
http://www.amputee-coalition.org/military-instep/feet.html
iWalk
product
BiOM
Hugh Herr’s company
http
://
blog.amsvans.com
www.newscientist.com
www.businessinsider.com
Google “Hugh Herr TED”Slide15
15
Odyssey – motorized
1 KHz control
www.springactive.com
JackSpring
–
motorized
www.springactive.com
Thomas Sugar, Professor
Arizona State UniversitySlide16
Prosthetic Knees
More than 100 models available
Single axis or polyaxialPassive: no electronicsMechanical frictionConstant
VariableHydraulicPneumaticActive: motor control
Semi-active: computer control but no motorsOttobock, Ossur,
Trulife, Freedom Innovations,Endolite (Dayton, Ohio), …
16
medi
OHP3/KHP3
www.medi.de/en/international/products/leg-prosthesesSlide17
Mauch SNS (swing and stance)
Ossur
PassiveHydraulic$5,000
17
www.ossur.com
Hans Adolph Mauch
(1906-1984)
German engineer until the end of WW II
Jet engine
and
prosthesis
development in
Germany
Moved to USA in 1945Slide18
18
www.ottobockus.com
C-Leg
Ottobock
Semi-active
Hydraulic
Introduced in 1997First microprocessor leg$50,000 retail
Otto Bock, 1881-1960
German
prosthetistSlide19
Rheo
Knee
OssurSemi-activeHydraulicIntroduced in 2005$17,000
19
www.stortz-koeln.de
Magnetorheological
fluid
has viscosity that depends on the surrounding magnetic fieldSlide20
Plie
Knee
Freedom InnovationsSemi-active: 100 HzHydraulic20
www.freedom-innovations.comSlide21
21
Image: National
Institute of Biomedical Imaging and
Bioengineering
F. Sup et al., “Self-Contained
Powered Knee and Ankle Prosthesis”
Vanderbilt Leg(aka bionic leg, or Goldfarb leg)Freedom Innovations
Integrated knee and ankle motors
Currently i
n testing
Controller gain scheduling depending on “walking phase”Slide22
22
proklinik.com.tr
Power Knee
Ossur
First active transfemoral prosthesis
Introduced in 2009
$60,000Slide23
Increase in energy consumption
Amputee with walker or crutches – 65%
Below-knee unilateral amputee – 15%Below-knee bilateral amputee – 30%Above-knee unilateral amputee – 65%Three times normal hip power on amputated side
Above-knee bilateral amputee – 200%“Microprocessor Prosthetic Knees,” by D.
Berry“Self-contained power knee and ankle prosthesis,” by F. Sup et al.
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Coordinate system
24
Direction of walking
Z
Y, right to left
X
Knee angle (positive)
Thigh angle (positive as shown)Slide25
Gait_Data_Sub3.xls, Normal Walk (Cleveland Clinic)
25
Able-Bodied Gait Data
Flexion
Extension
Flexion
Extension
Heel
Strike
Toe
Off
Stance Phase
Swing PhaseSlide26
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Able-Bodied Gait Data
Gait_Data_Sub3.xls, Normal Walk (Cleveland Clinic) -113.8 kg subject
Positive: Power Generated
by the Joint
Negative: Power Absorbed
by the Joint
Does not match published data wellSlide27
27
Discriminating age and disability effects in locomotion: neuromuscular adaptations in musculoskeletal
pathology, by Chris
A.
McGibbon
and David E. Krebs
Toe
Off
“Energy
generation and absorption at the ankle and knee during fast, natural, and slow
cadences
,”
by D. Winter, 1983
Figure 3 and Table 1
Able-Bodied Gait Data
Power = Torque * (Angular Velocity)
Normal walking speed
104.4 steps/minute
(52.2 strides/minute)
Ankle work = –7.8 + 25.6 = 17.8 J
Knee work = –6.3 + 3.7 – 9.6 – 8.4 = –20.6 J
The ankle requires energy
The knee absorbs energy
The net work done by the knee/angle combination is
negativeSlide28
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Kinematic and kinetic comparisons of transfemoral amputee gait using C-Leg
®
and Mauch SNS
®
prosthetic knees, by Ava D. Segal et al.
Prosthetic LimbC-leg: solid lineMauch leg: dashed line
Control group: dotted line
More hip power required for amputees
No stance knee flexion in prostheses
More negative knee power in prostheses
No ankle push-off with prostheses
1
2
3
4Slide29
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Kinematic and kinetic comparisons of transfemoral amputee gait using C-Leg
®
and Mauch SNS
®
prosthetic knees, by Ava D. Segal et al.
Intact LimbC-leg users: solid lineMauch leg
users: dashed line
Control group: dotted line
Limping (shorter steps) by amputees
More hip power in amputees
More ankle push-off
by amputees
1
2
3
ancillary
health
issuesSlide30
Prosthetics Research at CSU
Fall 2009 – Davis and van den
Bogert (CC) contact Simon about hydraulic prosthesis controlSpring 2010 – CC provides funding to CSUSummer 2010 – Davis leaves CC for Austen BioInnovation
Fall 2010 – van den Bogert leaves CC for self-employment
Fall 2011 –Richter begins design of hip robotSpring 2012 – Richter completes hip robotFall 2012 – CC project concludesFall 2012 – van den
Bogert moves to CSUSummer 2013 – Wright Center funds CSU for 1 yearFall 2013 – NSF funds CSU for 4 years
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