Download Medical Technology Bionics Experiments

Medical Technology: Bionics
Experiments
OUTCOME 2:
2.10 gather, identify data
sources, plan, choose
equipment or resources for,
perform a first-hand
investigation and analyse
information about changes in
the heartbeat rate before and
after physical activity


The heart rate increases when you exercise because your
heart and body requires more oxygen and must get rid of
carbon dioxide at a faster rate.
The heart beats faster and therefore the pulse rate
increases.
The heart rate of different people will vary due to a variety of
factors:
- Level of fitness – people with high levels of fitness tend to have
faster recovery rate after exercise
- Food intake before investigation
- Individual differences e.g. body weight
Independent variable: amount of activity
Dependent variable: rate of the heartbeat
Controlled variables: pace of exercise, timing of exercise
2.11 plan and perform an
investigation to identify
individual aspects that
comprise the heartbeat
Conclusion—the heart rate changes as the level of physical
activity changes. This is because as the pulse rate increases, the
body and heart require more oxygen. The cardiovascular system
links to the respiratory system to work the body’s muscles. The
body and heart needs to get rid of carbon dioxide at a faster rate.
 The heart contracts in the SYSTOLE phase and relaxed in
the DIASTOLE phase.
 The opening and closing of the heart valves cause “lub
dub” sounds.
 An electrocardiogram records the electrical activity of the
heart as it goes through its rhythmic beating process.
Senior Science – By Natalie C 2014
Electrocardiogram (ECG):
TP interval (ventricular diastole): atria and ventricles are
relaxed; blood flowing into atria via veins.
P wave (atrial systole): SA node fired, atria contracts, forcing all
blood into ventricles.
QR interval (end of ventricular diastole): the AV valves remain
open as all the remaining blood is squeezed into ventricles.
RS interval (ventricular systole): as the blood is now all within
the ventricles and so pressure is higher here than in atria, the AV
valves close. The ventricles start to contract.
ST segment (ventricular systole): pressure increase, causing the
SL valves to open, blood is ejected into aorta as ventricles
contract.
T wave (ventricular diastole): ventricles relax; pressure reduced;
causing SL valves to close.
2.12 identify data sources,
gather, process and analyse
information to outline the
historical development of
pacemakers and use available
evidence to identify types of
technological advances that
1950
1952
1957
1958
1959
Pacemaker worn externally, had external power
source
Pacemaker is able to be implanted into patient
through surgery
Battery-powered pacemaker
Internal pacemaker
Successful implantable pacemaker
Senior Science – By Natalie C 2014
have made their development
possible
1960s
1970s
1990s
Leads that could be fixed to the heart via a vein was
introduced
Leads with pronged or screw in ends were
developed; coating of pacemaker were improved to
titanium
More sophisticated, much smaller in size, more data
can be stored in them

2.13 process information to
identify different types of
functions of artificial valves in
the heart
Early pacemakers delivered an electric shock to the heart
of the person; device was plugged to wall socket
Technological advances that led to the development of the
modern day pacemaker:
1. Leads that attach to the wall of the heart
2. Portable battery
3. Surgically implanted
4. Development of smaller pacemakers
5. Improvements in design, battery life, materials used,
reprogramming outside the body
Mechanical valves
 E.g. ball and cage metal, disc in cage, bileaflet valve
 Ball and cage—metal housing with carbon discs; they
replicated the function of normal heart valves; very
durable
 Bileaflet valve—two semi-circular discs which open and
close; replicate function of normal heart valve; last
indefinitely
Biological valves
 E.g. pig, calf, human
 Made from animal tissue; is treated so it won’t be
rejected by recipient; less chances of rejection;
degenerate gradually (need replacements)
OUTCOME 3:
Senior Science – By Natalie C 2014
3.11 perform a first-hand
investigation to remove
calcium compounds from
chicken bones to examine
the flexible nature of bones



3.12 perform an
investigation to examine the
relationship between
cartilage, muscle, tendon
and bone in an animal limb
Bones consist of living and non-living parts. The non-living
part is made up of calcium which keeps the bones hard &
rigid. The living part includes strands of protein, called
collagen, which gives bones flexibility.
By removing the calcium in a chicken bone, via hydrochloric
acid, the hardness of the bone is removed.
Calcium & organic matter gives strength to bones.
Cartilage is a bluish white
rubbery tissue found in
humans. It is found at the
ends of bones & cushions
the bone against shock
(shock absorber) which
reduces friction.
Muscles make the body
move. The hold bones of the
skeleton together. Muscles
move bones by pulling on tendons.
A tendon is a strong white cord which connects muscle to bone.
When bones meet a joint is formed. Ligaments tie the bones
together at the joints (bone to bone).
Senior Science – By Natalie C 2014
3.13 perform an
investigation to
demonstrate the different
types of joints and the range
of movements they allow
Types of synovial joints in the body;
Body part
Shoulder, hip
Elbows, knees, ankles
Base of thumb
Spinal bones, tarsal
bones of feet & hands
Base of skull (neck)
3.14 process secondary
information to compare the
shock absorbing abilities of
different parts of bones
Range of movement
of the joint
- Side to side
- Back & forth
- Rotational
movements
- Back & forth
- Back & forth
- Side to side
- Back & forth
- Side to side
- End of one bone
rotates inside a ring
formed by the other
bone
Type of synovial joint
Ball and socket joint
Hinge joint
Double hinge joint
Sliding/gliding joint
Pivot joint
Comparing bone to cartilage, which has greater shock absorbing
ability, why?
 Cartilage has greater shock absorbing ability than bone
because it is flexible.
Discuss the shock absorbing ability of the different parts of the bone
(e.g. cartilage, tendons, muscle):
 A bone is generally made up of 2 types of tissue; spongy &
compact bone. The spongy, porous part of a bone is less
dense & has lower shock absorbing ability. Compact bone is
much denser & therefore has a higher rate of shock
Senior Science – By Natalie C 2014
absorption e.g. arms, legs.
3.15 plan, choose
equipment or resources for
and perform a first-hand
investigation to
demonstrate properties of
silicone such as acid
resistance, flexibility and
imperviousness to water
that make it suitable for use
in bionics
3.16 analyse secondary
information to compare the
strength of UHMWPE and
“superalloy” metal
Conclusion – different parts of the bone have different shock
absorbing abilities due to their density & structure. The bone has
different elasticity than the cartilage between the bones. Cartilage
is designed to absorb more shock because it acts as a “cushion”
between the bones. It is flexible but strong, supportive tissue.
Relating to silicone...
Flexibility – very flexible, soft and sticky
Resistance to acid – high resistance, does not change shape &
hardens slightly to stay together
Imperviousness to water – high imperviousness, silicone is not
penetrated by water
Effect of body temperature – hardens and sticks to itself
Independent variable: condition in which the silicone sample is
subjected to
Dependent variable: flexibility, acid resistance, water
imperviousness
Controlled variables: time, amount of silicone
Silicone has the characteristics of being inert, flexible, water
resistant, acid resistant, and easy to shape which makes it an
optimal material for the use in bionics.
Comparison of stainless steel & titanium alloys;
Property
Stainless steel
Titanium alloy
UHMEPE
Ultra high
molecular
weight
polyethylene
Tensile strength
Elasticity
Density
960
200
7.8
960
110
4.5
17
700
0.95
OUTCOME 4:
4.6 perform an investigation to
model the action of the diaphragm
in inhalation and exhalation
Air enters the lungs when the chest cavity is expanded. To do
this, the ribs are pulled outward & the diaphragm contracts &
moves downward.
Senior Science – By Natalie C 2014
Air is exhaled when the muscles relax
& the diaphragm moves up to its
original position.
4.7 perform a first-hand
investigation to identify carbon
dioxide in inhaled air and in
exhaled air and determine
which has the greater
concentration
4.8 gather, process and present
information from secondary
sources to identify monitoring and
other devices that constitute life
support systems and use available
evidence to explain their roles in
maintaining life.



Inhalation – diaphragm contracts
(moves down)
Exhalation – diaphragm relaxes
(moves up)
The air we breathe in contains about 21% oxygen &
0.03% carbon dioxide.
Immediately exhaled air contains 16% oxygen & 4%
carbon dioxide.
In this experiment, lime water is the indicator of the
presence of carbon dioxide. The greater the amount of
carbon dioxide the more precipitate is produced & the
“whiter” the solution.
Kidney dialysis machine
The kidney dialysis machine is a device which replaces the
function of the kidney when the patient’s kidney is not doing
the job adequately. The kidney’s function is to filter blood &
remove wastes & toxins from the human body.
This dialysis machine filters blood by removing wastes. It is
connected to a patient through a tube in the patient’s artery in
which the blood flows into the device where the blood is
filtered. Then a separate tube carries blood back into a vein into
the arm.
The kidney dialysis machine as a life support system helps to
maintain life by filtering blood which is essential in removing
waste from the body. If the wastes were not properly removed
Senior Science – By Natalie C 2014
then the toxins would build up & the patient can die as a result.
OUTCOME 5:
5.4 identify data sources, gather,
process, analyse and present
information to discuss the
advantages and disadvantages of
non-invasive and minimally
invasive medical techniques
Non-invasive techniques
General advantages – less risk to patient, fewer side effects,
less chance of infections, faster recovery time, less need for
medication.
General disadvantages – limited number of treatments per
year (x-rays have radiation)
Advantages & disadvantages of non-invasive techniques;
X-rays – Adv; cheap, widely available, provides images of
bones & internal organs. Dis; only 2D, may be hard to
interpret, cannot see structures deep within tissue, amount
of x-rays must be limited (as it can damage or destroy tissue:
cancer)
CAT scan – Adv; clearer than x-ray, allows the changes in
organs as they work to be viewed, e.g. blood flow. Dis;
require more skill to interpret images, more expensive
Ultrasound – Adv; can examine many areas of the body,
pregnancy: no risk to mother or baby. Dis; cannot determine
conditions of the bone or lungs.
MRI – Adv; provides very detailed images, good for diagnosis
of many conditions (MS, tumours, infections, strokes), 3D, no
radiation. Dis; some people cannot have MRI (pacemakers,
dentures), long procedure, very expensive, difficult for
claustrophobic patients.
Thermography – Adv; large areas can be assessed, safe &
fast, no pain or radiation. Dis; extremely expensive, images
are hard to interpret
Minimally invasive techniques
General advantages – keyhole: allows surgeon to view inside
the body without making large incisions, smaller scars, less
pain, less risk of infection
General disadvantages – endoscopes only allow a small area
to be illuminated at a time, may not detect some conditions,
risk of infection
5.5 gather, process and analyse
information and use available
evidence to discuss how

How the discovery of ultrasound led to the
understanding of blood flow in the body
A Doppler ultrasound is a non-invasive test that can be used
Senior Science – By Natalie C 2014
technological developments have
impacted on the understanding of
how the body works
to estimate the blood flow in blood vessels by bouncing highfrequency soundwaves (ultrasound) off circulating red blood
cells. A regular ultrasound uses soundwaves to produce
images, but can’t show blood flow.
It may help to diagnose many conditions – blood clots, poorly
functioning valves in leg veins (venous insufficiency), heart
valve defects and congenital heart disease, blocked arteries,
decreased blood circulation to legs (peripheral artery
disease), bulging arteries (aneurysms), narrowing of arteries.

How the discovery of x-rays led to the understanding of
bones and its movements
The x-ray machine helped to revolutionise how doctors
detected disease & injury. X-rays were used in treatment of
illnesses like real & imaginary pains. The discovery allowed
doctors to see inside the human body for the first time
without surgery. X-rays provided insight into our skeletal
systems which was an important step in understanding how
the human body functions – movement-wise.

How antibiotic developments were important in
understanding how the body’s immune system works
Antibiotics are a group of medicines that are used to treat
infections caused by bacteria & certain parasites. Antibiotics
do not aid the immune system, it weakens it but replaces one
of its functions. They only work on bacterial infections –
these chemicals kill the bacteria cells but do not affect cells
that make up the body.
Sometimes the body’s immune system is unable to activate
itself quickly enough to outpace the reproductive rate of
harmful bacteria. Other times, the bacteria are producing
toxins so quickly they will cause permanent damage before
the immune system does it jobs. In these cases, the immune
system needs help from something that can kill the invading
bacteria directly (antibiotics).
Senior Science – By Natalie C 2014