Senior Science
9.3 Medical Technology – Bionics
Section 1
Biomaterials
And
implants
© P Wilkinson 2002-04
9.3.1 Increases in scientific understanding and technological advances have
broadened options for maintaining humans as functioning organisms
9.3.1 a
Identify parts of the body and the biomaterials and biomedical devices that can be
used to replace damaged or diseased body parts including
– pins, screws and plates
– artificial joints
– pacemakers,
– artificial valves
– crowns, dentures,
– lenses
– prosthetic limbs
– cochlear implants
9.3.1 i
Gather and process information from secondary sources to trace the historical
development of one of the following implants:

cochlear implants

artificial valves
© P Wilkinson 2002-04
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Introduction
Many people today live active and productive lives because of biomaterials and biomedical
devices. These either temporarily or permanently replace missing or faulty parts of the body.
These materials and devices can have a significant impact on a person’s quality of life and
the length of life.
Early artificial body parts were relatively crude. The earliest known artificial body part was a
leg made about 300 BC. It was made with metal plates surrounding a wooden centre. Since
then a variety of such devices were developed – the classical hook for a hand, wooden pegs
for legs as well as wooden and ivory teeth.
Today a huge variety of artificial body parts are used. Braces for teeth, breast and penile
implants, contact lens and false fingernails are all used because of their impact on the quality
of life. A renal dialysis machine and artificial heart valves are modern technologies that
obviously impact on the quality of life.
The development and fitting of biomaterials and biomedical devices is an industry that is
currently worth billions of dollars a year. The development of artificial parts is part of the
science of biomedical engineering. Since the mid-1970s use of the term bionics has become
increasingly popular among the general public to describe work on artificial organs and
related medical devices. Scientists who work with such devices generally do not use the
term.
Bionics is usually taken to mean designing electronic and mechanical devices that copy the
behaviour of parts of the human body. The term was originally applied to a variety of
scientific projects involving biological systems, engineering systems, and artificial intelligence.
Many of the projects used biological principles to solve engineering problems.
Biomedical engineering is the application of engineering techniques and principles to the
diagnosis and treatment of illness and injury.
Biomechanics is a sub-branch of Biomedical Engineering concerned with using the theory of
mechanics to increase understanding of the normal movements of the body and to design
artificial body parts that work in a similar way and can act as replacements.
Prothesis Is an artificial body part (replacing or supporting a natural part of the body eg teeth, eye, bone)
© P Wilkinson 2002-04
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9.3.1 a
Identify parts of the body and the biomaterials and biomedical devices that can be
used to replace damaged or diseased body parts including
– pins, screws and plates
– artificial joints
– pacemakers,
– artificial valves
– crowns, dentures,
– lenses
– prosthetic limbs,
– cochlear implants
Activity 1 – 1
Diagram
Biomaterials and biomedical devices
Replacing body parts
EYES
Lens implants to correct damage
caused by cataracts.
EARS
Cochlear implants to
replace damaged inner
ear
TEETH
Metal-ceramic crown attached
to root by a metal screw.
HEART
Artificial pacemakers
maintaining heartbeat.
BREAST
Breasts are enlarged with
saline or silicon sacs
HEART
Replacement
of
damaged valves by
artificial
heart
valves.
LIMBS
Stainless steel pins,
screws to repair broken
bones
SYNTHETIC SKIN
To prevent infection artificial; skin made from
keratin ( a component of hair) and chitosan ( a
starchy substance found in insect skeletons)
© P Wilkinson 2002-04
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Table
Replacing body parts
Heart pacemaker provides cardiac pacing for hearts with irregular heartbeat. Made using
titanium and epoxy over lithium battery microelectronics (by Cardiac Control Systems).
Penile prothesis is inserted into the corpora cavernosem, Made from silicone elastomer (by
Surgitek).
Great toe joint is often implanted during bunion operations. Made using silicone elastomer
with titanium grommets (Swanson design by Dow Corning Wright).
Adjustable femoral (upper leg bone) implant replaces cancerous bone removed from growing
children. Every six months the surgeon makes a small incision and inserts a turnkey to extend
the tubular prothesis like a car jack. Made using cobalt-chromium & molybdenum alloys and
advance polyurethane (Lewis design, by Dow Corning Wright).
Hydrocephalus shunt carries “water on the brain” via a catheter to the abdomen to be
reabsorbed. Made using silicone elastomer (Armes design by Dow Corning Wright).
Pectus implant expands the chest for persons born with a depressed sternum. Made using
silicone elastomer (by Dow Corning Wright).
Hip implant uses a composite femerol stem of thermoplastic reinforced with carbon fibre. Still
undergoing tests, the composite is believed to rival bone’s flexibility. Composite Stem,
Ceramic Ball and titanium Socket, by Zimmer.
Testicular implant replaces one or both testicles after surgical removal or when missing at
birth, Silicone Elastomer, by Surgitek.
Multifocal intraocular lens for the eye restores near and distant vision after the removal of
cataracts. Polymethylmethacrylate. by Lolab.
Nose implant for cosmetic reshaping. Silicone Elastomer, by Dow Corning Wright.
Mandibular mesh of titanium, a biocompatible metal, provides a foundation for jaw
reconstruction after loss of bone through disease or accident by Techmedica.
Shoulder prothesis mimics bone structure. The stem fits into the humerus, the socket onto the
scapula, Titanium Stem; Socket of plastic-lined titanium by Intermedics.
Dialysis-access graft links a major artery and vein in kidney failure patients to permit
withdrawal of blood for cleansing and return to the body, Gore-tex, by WL Gore.
Absorbable pins fix in place bony or cartilaginous fragments, eliminating surgery to remove
metal pins. Polymer by Johnson and Johnson.
Hip implant employs a zirconia ceramic ball on a titanium-alloy stem. Titanium beads on the
upper stem and acetabular shell encourage in growth of bone for improved fixation by
Richards.
Artificial leg flexes at the knee, ankle and arch, socket and foot, plastic knee and ankle,
titanium and alloys; shin, composite by Sabolich
© P Wilkinson 2002-04
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What to do
1. Read the information biomaterials and biomedical (prothesis) devices in the diagram
and table above.
2. Access the following Internet site and read information biomaterials and biomedical
devices.
http:/hsc.csu.edu.au/senior_science/core/bionics

Go to the medical technology – Bionics 1
3. Process the information and put it into the table like the one below. Use only those
materials or devices that are used to replace damaged or diseased body parts.
Body Part
© P Wilkinson 2002-04
Biomaterial used
Biomedical device used
6
Reasons for use
of artificial part
9.3.1 i
Gather and process information from secondary sources to trace the historical
development of one of the following implants:

cochlear implants

artificial valves
Joint Prostheses: Processing information
A joint in the body is a place where two or more bones meet in the skeleton. There are three
main kinds of movable joints – hinge joints, pivot joints and ball and socket joints. Ball-andsocket joints allow the greatest range of movement. These joints consist of a large round
end of a long bone fitting into a hollow in another bone. The hip and the shoulder both have a
ball-and-socket joint. In the United States alone there are over 100,000 knee joints replaced
every year by an artificial one. Artificial body parts are also known as prostheses.
HISTORY OF JOINT PROSTHESES
1. 1890 – Ivory used for the 1ST implantation of a total prosthesis. It was unsuccessful due to
problem with biocompatibility and the technique for fixation.
2. 1951 – 1st use of pure titanium for plates, screws for bone fractures.
3. Late 1950s – 1st total hip prosthesis. Co-28Cr-6Mo cast alloy (excellent corrosion
resistance in the body and high wear resistance). Used for cup, ball and stem.
4. 1962 – Introduction of Ultra High Molecular Weight Polyethylene (UHMWPE) – partly
crystalline linear homopolymer of ethylene. Used for cup with a steel ball. The thickwalled polyethylene cup and steel ball almost completely replaced the metal/metal
pairings in the 1970s. This was due to the high loosening rates with the ”micro-fit” allmetal prothesis.
5. Early 1970s – pure titanium replaced by Ti-6Al-4V alloy.
- Aluminium oxide ceramic/ceramic pairing for the cup and ball of hip
prothesis.
7 1975 – Ceramic balls in sliding pairings with polyethylene cups.
8 Early 1980s – Ti-5Al-2.5Fe alloy used CoCrMoC metal/metal pairings brought back
because of the very satisfactory low wear valves in the prostheses of the 60s.
9 1988 – 1st cement free total hip prostheses developed metal/metal.
REFERENCES
Salzer Medical Technology
Materials for Artificial Joints RM Streicher
Classic and new Titorium Alloys for Production of Artificial Hip Joints R Semlitsch
A Solution to the problem of wear of hip joint replacements M Semiltsch
© P Wilkinson 2002-04
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What to do Research assignment
Gather and process information from secondary sources to trace the historical development
of one of the following implants:

cochlear implants

artificial valves
Presentation
Your work should be presented in a table similar to the one shown below.
Date/Year
Development
Marking criteria
© P Wilkinson 2002-04
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