An applied interdisciplinary science that integrates
mechanical elements, electronics and parts of biological
Includes aspects of biology, mechanics and electronics
Incorporates robotics and neuroscience
Aims to develop devices that interact with human
muscle, skeleton and nervous system
First recorded illustration of prosthetic replacement appears in the RigVeda, a religious text written in Sanskrit, compiled between 3,500 and
1,800 B.C. in India.
In 1504, the Iron Hand of knight Götz von Berlichingen was constructed by
an armourer and with the help of gearwheels the fingers could be revolved
and fixed at a certain position.
In 1909, D. W. Dorrance invented a split hook that was anchored to the
opposite shoulder and could be opened with a strap across the back and
closed by rubber bands.
Fig: The Iron Hand of Götz von
1915, Sauerbruch's hand was devised by a
German surgeon Ernst Ferdinand Sauerbruch in
collaboration with Aurel Stodola Slovak physicist,
turbine engineer and professor of mechanics which
was controlled and powered directly from surgically
prepared muscles of the residual limb.
Image Sources: http://www.maximumpc.com/files/u134761/gotz.jpg
Simulated Fingers & Hands
Helps regain human motor control
that was lost or impaired by
trauma, disease or birth defects.
Allows disabled people to become
Image Sources: http://www.wired.com/images_blogs/gadgetlab/2009/11/arms_2a.jpg
Simulated Fingers & Hands
Mind-controlled: movement of the prosthetic is driven
solely by the electrical impulses of the brain
Myoelectric: detects electrical changes in the muscles
of the stump and converts them into movements
Body-powered/Cable-controlled: controlled by cables
connecting the prosthetic limbs elsewhere on the body
Hybrid: combines two types of control in the same
Image Source: http://images.gizmag.com/inline/thought_controlled_permanent_prosthetic_arm-2.jpg
Simple Body-powered Prosthetic
Extending the arm or flexing the
shoulder pulls a cable attached
to a harness on the user‟s back.
As the cable tightens, it opens a
split hook at the end of the arm
and reversing the move closes
This prosthetic arm also
provides a sensory feedbackforce which gets felt by the
Image and information sources: http://rehabeasy.blogspot.co.uk/2008/10/bionic-arm-mechanism.html
Materials used in
Simulated Hands &
In the past iron, steel, copper and wood were the major
At the present, following materials used serve specific
Titanium: lightweight, provides longer life and durability
Aluminium: lightweight and durable
Thermoplastics sockets: lightweight and give prosthesis
recipients extended comfort at the site the prosthesis is
Carbon fibre: forms lightweight pylon and gives amputees
A company called „i-limb‟ has a product called the „i-digits‟ which provide
personalized electronic digits for people who have loss up to five fingers.
However, the patient must pass a selection criteria to be considered.
Each prosthetic is unique to fit the hand of the patient.
It is battery powered.
The interface material is silicone to avoid damage done to the skin and
The „i-digit‟ is controlled using myoelectrodes or force-sensing resistors
(FSR's). The electrodes can sense muscle contraction. This contraction
is filtered and processed to tell the fingers to open or close.
The prosthetic can be covered with a silicon material to match the colour
and appearance of the patient's skin.
Image source: http://www.touchbionics.com/media/2197/i-limb-digits_coverings_match2.jpg
Developed by „Didrick Material‟.
Unlike the „i-digit‟ it is not electronic and does not require a power
Made from surgical steel and is lightweight
Are able to bend naturally with the movements from residual fingers.
It is body powered meaning that the movements of the prosthetic fingers
are determined by the movements of the residual finger
This makes it user friendly and does not require any training
Each „x finger‟ is independent which allows for more articulation control,
claimed to be able to grip golf clubs and play musical instruments.
A silicone cover can be applied to match the appearance of the user‟s
Costs are estimated to be $1000 per digit.
Image Sources: http://www.wired.com/images/article/full/2007/07/xfinger_full.jpg
Aid vs. Enhancement:
“Bionic hand for 'elective amputation' patient”
-Neil Bowdler, BBC News
If people with minor damages to their hands undergo amputation and replace their
hands with simulated hands for better function today, then will people with healthy
hands undergo amputation if technologically advanced simulated hands with
extraordinary features are developed in the future? Will it devalue natural hands
Transradial, below the elbow, prostheses cost between £4,000 and £5,500.
Transhumeral, below the shoulder, prostheses cost between £6,500 and £10,000.
Body-powered prostheses cost approximately £4,500 and Myoelectric prostheses cost approximately
Repair costs are approximately £500 annually and the prostheses need replacing every 4 to 5 years.
E.E., 2013. A Brief Review of the History of Amputations and Prostheses. ICIB 1976 Vol. 15, Num. 5, p.15-16.
Retrieved April 12, 2013, from http://www.acpoc.org/library/1976_05_015.asp
Arm through the Ages. 2013. Retrieved April 12, 2013 from http://www.medicatradefair.com/cipp/md_medica/custom/pub/content,oid,23173/lang,2/ticket,g_u_e_s_t/~/Prosthetic_Arms_through_the_Ages.html
How: Artificial Limb. 2013. Retrieved April 12, 2013, from http://www.madehow.com/Volume-1/Artificial-Limb.html
Sauerbruch’s hand. 2013. Retrieved April 12, 2013, from http://www.whonamedit.com/synd.cfm/3966.html
N., 2011. Bionic hand for „elective amputation‟ patient. BBC News Science & Environment. Retrieved April 12, 2013, from
E., 2005. Cost of prosthetics stirs debate. The Boston Globe. Retrieved April 12, 2013, from
A., JAMES, M., SELF, B.P., COLEMAN R. & DENARO B., 2013. DETERMINING USAGE OF A JUVENILE MYOELECTRIC
PROSTHETIC ARM. ACPOC News 2002 Vol. 8, Num. 4, p.17-18, 20, 22, 24, 25. Retrieved April 12, 2013, from
C.W., 2011. Upper Limb Prostheses. WorkSafeBC Evidence-Based Practice Group, p. 6. Retrieved April 12, 2013, from
Fingers prosthetic designed to replace lost digits’- cnet retrieved 21/04/13 at http://news.cnet.com/8301-17938_105-200716971/x-fingers-prosthetic-designed-to-replace-lost-digits/
Fingers Give Strength, Speed to Amputees’- Wired retrieved 21/04/13 at
Bionics, retrieved 21/04/13 at http://www.touchbionics.com/products/active-prostheses/i-limb-digits/technical-information/