Answer to Quiz
Tom Whittaker, a British, the first person without a leg to
climb the Everest 1998
Arunima Sinha, UP, India, the first woman without a leg
to climb the Everest 2013
• An artificial device that replaces a
missing body part
• ORTHOSIS: Splints
The 5th Egyptian Dynasty (2750-2625 B.C.); archaeologists have
unearthed the oldest known splint from that period.
Image source: http://www.egyptarchive.co.uk/html/hidden_treasures/hidden_treasures_31.html
Prosthetic care History
• The 5th Egyptian Dynasty (2750-2625 B.C.);
• The earliest written reference:
Herodotus,500 B.C., wrote of a prisoner who
escaped from his chains by cutting off his
foot, which he later replaced with a wooden
• An artificial limb from 300 B.C.: A copper &
wood leg (unearthed at Capri, Italy in 1858.)
Ancient to Modern technology
• The earliest recorded mention is the
warrior queen Vishpala in the Rigveda.
• Rigveda : 1000 BC
• In 1529, French surgeon, Ambroise
Pare (1510-1590) introduced amputation as
a lifesaving measure in medicine. He started
developing prosthetic limbs scientifically
Blade Runner’ Pistorius
2012 Summer Olympics, London
A Good prostheses design –
Must minimize the risk of injury associated with
stumbling, slipping and falling.
(soft tissue and bones)
“Jaipur foot”: 1969.
• Dr P K Sethi: Orthopedic surgeon.
• An inexpensive and
flexible artificial limb.
• Ram C Sharma, co-invented the
The Jaipur foot
Inexpensive prosthetic foot – India
Made of vulcanized rubber
Consists of three inserts: fore-foot and heel of micro cellular rubber
and an ankle of laminated wood
• Flexibility in three planes
• Well suited for walking over uneven terrain, climbing trees, etc.
In case of partial amputation, inserts within a conventional shoe are can be
In general, it is realized via flexible keel, which provides non-linear spring action
similar to the push-off phase of walking or running.
DYNAMIC RESPONSE FEET
The distinguishing characteristic of this
group is a plastic spring mechanism in
the keel which deflects during heel off
and returns to its resting position during
toe off. Often called "energy storing" by
manufacturers, these feet provide a
subjective sense of push-off for the
wearer, a more normal range of
motion, and a more symmetric gait.
Single axis solid ankle cushioned heel (SACH) prosthetic foot – provides planar
flexion and smooth transition to mid-stance; increased knee stability; best
suited for short-term use, such as on preparatory devices or for elders who
may walk with a shuffling gait and never fully load the forefoot.
Africa: Low Cost design
Int. Com Red Cross
Design considerations& Performance
factors to consider when designing a prosthesis.
Fit – athletic/active amputees, or those
with bony residua, may require a
Ground compliance – stability independent of
terrain type and angle
carefully detailed socket fit; less-active
Rotation – ease of changing direction
patients may be comfortable with a
Weight – maximizing comfort, balance and
'total contact' fit and gel liner
Energy storage and return – storage of
Suspension – how the socket will join and fit to
energy acquired through ground contact
and utilization of that stored energy for
Energy absorption – minimizing the
effect of high impact on the
The patient’s concerns
Ease of use
Knee joint – much important component
• It should be lightweight
and safe in operation.
• Simple mechanical
• Low functionality
• Doesn’t allow
bending during the
3R45 Modular Knee Joint
An optimal gait pattern is
achieved by adjusting the
independent swing phase
flexion and extension
• They allow stance and swing phase control; Adjustment of
the swing phase to suit to individual’s pattern of walking.
• Hydraulic resistance to flexion;
• Lock of the knee joint in hyperextension;
• Unlock the joint when the forces to the prosthetic forefoot
• Manual lock option: for activities which require maximal
stability (driving ,standing on a bus, vocational activities);
• Release for maximum flexibility.
• Piston and a hydraulic cylinder.
• The cylinder is perforated to allow fluid to flow from one
side of the cylinder to the opposite side when the piston
• The distribution of the holes within the cylinder determines
the amount of damping.
• Hydraulic cylinder and piston.
• Holes on the cylinder ends and electromagnet-controlled
valve determine the fluid flow.
• Microprocessor control unit and a hall-effect sensor for
and a swing-phase
Four bar linkage knee The
The most common type of
mechanism is the four-bar
linkage in a modern day
Prosthetic gait analysis
Biomechanical techniques for assessing the adaptation of the user to the prostheses:
Gait analysis & force-reactions measurement are important & can be measured
•Prosthethic limbs do not provide direct proprioceptive feedback.
•Force information is transferred via the socket.
•Often prostheses produce sound or vibrations with the force and cadence.
People with lower-limb prostheses use a higher oxygen consumption, which
varies to the different model prostheses.
ANSYS has pioneered the development and application of Simulation Methods to
solve the most challenging product engineering problems. Simulation software
enables organizations to confidently predict how their products will operate in the real
CAD-CAM design: Custom Fit
CAD-CAM design can be applied in
the socket production.
The wire-frame model
representation of the socket
Quantification and automation of
prosthesis and custom footwear
design and manufacture
Microprocessor controlled prosthesis
• The main advantage of
controlled prosthesis is
closer approximation to
an amputee’s natural
The Endolite intelligent prosthesis
(in different cadences)
which controls a needle
valve, via a stepper motor
•The controller is
programmed to provide an
optimal damping in
different walking patterns.
Myoelectric Versus Mechanical body powered prosthesis
• Uses Electromyography Signals or potentials from voluntarily contracted
muscles within a person's residual limb on the surface of the skin to control
the movements of the prosthesis
• Elbow flexion/extension, wrist supination/pronation (rotation) or hand
opening/closing of the fingers.
• Utilizes the residual neuro-muscular system of the human body to control
the functions of an electric powered prosthetic hand, wrist or elbow.
• It has a self suspending socket with pick up electrodes placed over flexors
and extensors for the movement of flexion and extension respectively.
• The first commercial myoelectric arm was developed in 1964 by the Central
Prosthetic Research Institute of the USSR, and distributed by the Hangar
Limb Factory of the UK.
Advancements in the processors used in myoelectric arms has allowed to make gains in fine tuned control
of the prosthetic.
The Boston Digital Arm is a recent artificial limb that has taken advantage of these more advanced
processors. The arm allows movement in five axes and allows the arm to be programmed for a more
Recently the i-Limb hand, invented in Edinburgh, Scotland, by David Gow has become the first
commercially available hand prosthesis with five individually powered digits. The hand also possesses a
manually rotatable thumb which is operated passively by the user and allows the hand to grip in
precision, power and key grip modes.
The hand, manufactured by "Touch Bionics“ of Scotland (a Livingston company), 2007 in Britain.
Another neural prosthetic is Johns Hopkins University Applied Physics Laboratory Proto 1. & Proto 2
Having artificial body parts, esp. electromechanical
ones. Having ordinary human powers increased by
or as if by the aid of such devices
Integrated prosthetic legs are the
"holy grail" for amputees
The change has been "fantastic
• Flexfoot Cheetah carbon-fibre
running blades by Össur
• Born without fibulae and
with malformed feet, his legs
were amputated about
halfway between knee and
ankle so he could wear
Italian racer Alex Zanardi made
careers in both CART and Formula
In September of 2001, he was
leading a race when a near-fatal
accident caused him to lose both
legs above the knee.
Rather than retire, Zanardi
designed his own prosthetic legs.
By 2003 he was racing again with a
car modified with a handcontrolled accelerator and brakes,
and was racing full time again by
3-D spatial geometry and
surface topography of
amputee’s residual limbs
Fit and forget prosthesis
TECHNOLOGY & InnOVATion
Merging the body With the machine
12% overlap : Biology & Technology
The first robotic arm which is mind-controlled and
can be permanently attached to the body
• Early in 2013, Chalmers
University of Technology,
and Sahlgrenska University
Hospital in Sweden,
succeeded in making the
first robotic arm which is
• It can be permanently
attached to the body
• Max Ortiz Catalan and
A new study it is hoped that artificial hands could regain their sense of touch.
By surgically connecting the brain with an artificial fingertip equipped with
sensors, researchers found that it is possible for animals to feel contact and pressure
with their hands, paving the way for human trial.
Contact sensor, to signal the start and end of handling an object; and a force
sensor, to determine how much strength to exert on an object.
A computer then monitors the amount of force that is exerted on the prosthetic
finger, then analyzes the information and delivers an electrical stimulus to the brain,
which they hope will create a sensation that mimics what a real hand would feel.
Bensmaia et al "Behavioral Demonstration of a Somatosensory Neuroprosthesis" Transactions on Neural
Systems and Rehabilitation Engineering
Post-Traumatic Stress Disorder in combatants.
41.7% suffered from Post-Traumatic Stress
42.5% of the lower limb amputees, 33.3%
of the upper limb amputees had symptoms
compatible with PTSD
This study highlights the need to pay more
attention in providing psychological care as
a part of the overall health management of
Abeyasinghe , de Zoysa , Bandara et al
The prevalence of symptoms of Post-Traumatic
Stress Disorder among soldiers with amputation
of a limb or spinal injury: a report from a
rehabilitation centre in Sri Lanka. Psychol
Health Med. 2012;17(3):376-81.
Lower limb amputees had 50%
more complications than upper limb
Two-thirds of patients had a mental
health disorder with rates of major
disorder categories between 18%
Melcer T, Walker GJ, Galarneau et al
Midterm health and personnel outcomes
of recent combat amputees. Mil Med.
Ramachandran’s mirror therapy.
V.S. Ramachandran, University of
California, devised this therapy.
His patient complained an
excruciating phantom arm: Felt
that phantom hand was clenched
so tightly that the fingernails were
digging into his phantom palm.
Ramachandran came up with an
unusual treatment: Placed a mirror
in a cardboard box and instructed
the patient to place his existing
hand inside the box, next to the
When the patient looked down at
the mirror, the reflection of his
existing hand stood in as a visual
replacement of his phantom limb
• The patient was told to imagine
that the reflection was in fact the
lost limb, and to practice
clenching and unclenching his
hand while looking in the mirror.
• To the patient's surprise after two
weeks, pain vanished
• Mirror Therapy is now being
adopted by many doctors to
combat phantom pain. It can
also be used to aide people
who have had a stroke and
other types of pain
“You never conquer a mountain. Mountains can't be conquered; you conquer yourself
And… if you aren't living on the edge, you are taking up too much space”
Merging the body With the machine
Touch sensitive & interactive prosthesis