Artificial limb

Evolution of Artificial limbs

Dr Bhaskar BorgohainAssociate Professor and HoD i/c

Deptt of Orthopaedics NEIGRIHMS

QUIZ

Connection?

Students

Others

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

PROSTHESIS

• An artificial device that replaces a missing body part

• EXOPROSTHESIS

• ORTHOSIS: Splints

Image source: http://www.egyptarchive.co.uk/html/hidden_treasures/hidden_treasures_31.html

Egyptian Mummy:The 5th Egyptian Dynasty (2750-2625 B.C.); archaeologists have unearthed the oldest known splint from that period.

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 substitute.

• 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

LOWER-EXTREMITY PROSTHESES

Socket

Residual limb (soft tissue and bones)

(Customized component)

A Good prostheses design – Must minimize the risk of injury associated with stumbling, slipping and falling.

“Jaipur foot”: 1969.

• Dr P K Sethi: Orthopedic surgeon. (1927 –2008)• An inexpensive and

flexible artificial limb.• Ram C Sharma, co-invented the

“Jaipur foot”

Rehabilitation engineering

• Inexpensive prosthetic foot – India• Made of vulcanized rubber• Wooden keel• 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.

The Jaipur foot

In case of partial amputation, inserts within a conventional shoe are can be applied.

Energy-stored feet.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 FOOT

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.

ICRCInt. Com Red Cross

Africa: Low Cost design

Design considerations& Performancefactors to consider when designing a prosthesis.

• Fit – athletic/active amputees, or those

with bony residua, may require a carefully

detailed socket fit; less-active patients may

be comfortable with a 'total contact' fit and

gel liner

• Energy storage and return – storage of

energy acquired through ground contact

and utilization of that stored energy for

propulsion

• Energy absorption – minimizing the effect

of high impact on the musculoskeletal

system

• Ground compliance – stability independent of

terrain type and angle

• Rotation – ease of changing direction

• Weight – maximizing comfort, balance and

speed

• Suspension – how the socket will join and fit to

the limb

The patient’s concerns

• Cosmetics• Cost• Ease of use• Size availability

Knee joint – much important component

• It should be lightweight and safe in operation.

• Simple mechanical /manually operated locking mechanism

• Low functionality• Doesn’t allow

bending during the swing phase.

Otto-Bock knee prostheses:

An optimal gait pattern is achieved by adjusting the independent swing phase flexion and extension resistances

3R45 Modular Knee Joint

Integrated miniature hydraulic cylinder

Hydraulic knees• 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 exceed threshold;

• Manual lock option: for activities which require maximal stability (driving ,standing on a bus, vocational activities);

• Release for maximum flexibility.

Solutions:• 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 moves.

• 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 knee-bending measurement.

3R80 Modular Rotary Hydraulic Knee Joint

• Weight activated; • Cadence responsive; • Precise adjustability; • 135 degree flexion angle; • Independently adjustable hydraulic flexion and extension resistance.

Pneumatic cylinder and a swing-phase controller.

Four bar linkage knee The

The most common type of mechanism is the four-bar linkage in a modern day prosthesis

Prosthetic gait analysis

•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.

Biomechanical techniques for assessing the adaptation of the user to the prostheses:Gait analysis & force-reactions measurement are important & can be measured

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 world.

CAD-CAM design: Custom Fit

• CAD-CAM design can be applied in the socket production.

• The wire-frame model representation of the socket modified.

• Quantification and automation of prosthesis and custom footwear design and manufacture

Microprocessor controlled prosthesis

• C-Leg• The main advantage of

microprocessor controlled prosthesis is closer approximation to an amputee’s natural gait

The C-Leg

The Endolite intelligent prosthesis

•Swing-phase controller (in different cadences)•4-bit microprocessor 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.

Robotic arms• 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 customized feel.

• 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 in 2010.

Bionics

Having artificial body parts, esp. electromechanical ones. Having ordinary human powers increased by or as if by the aid of such devices

Where are we heading to…?

OSSEOINTEGRATION

DEEP BONY PROPIOCEPTION

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 prosthetic legs.

Italian racer Alex Zanardi made careers in both CART and Formula One racing. 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 hand-controlled accelerator and brakes, and was racing full time again by 2005.

3-D spatial geometry and surface topography of amputee’s residual limbs

Neural extension

Thought command

Fit and forget prosthesis

THE FUTURE

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 mind-controlled

• It can be permanently attached to the body

• Osseointegration• Max Ortiz Catalan

and Rickard Brånemark

Somato-sensory Neuro-prosthesis

• 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 

PSYCHOLOGY

• PHANTOM LIMB• PTSD

Sigmund Freud

PHANTOM PAIN

Post-Traumatic Stress Disorder in combatants. 

• 41.7% suffered from Post-Traumatic Stress Disorder.

• 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 injured combatants. 

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 amputees.

• Two-thirds of patients had a mental health disorder with rates of major disorder categories between 18% and 25%.

Melcer T, Walker GJ, Galarneau et al Midterm health and personnel outcomes of recent combat amputees. Mil Med. 2010 Mar;175(3):147-54.

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 mirror.

• 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 conditions.

“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

THANK YOU