biomechanics introduction

3. Body Parts
• Nowadays it is speculated that a human
could be replaced bit by bit/organ by
organ
• How true is this?
• Excepting the brain and Neuroprosthetics,
what about human organ replacement?
• Artificial devices not transplants

5. Body Parts
• Artificial Hearts
• Artificial Lungs
• Artificial Kidneys
• Artificial Pancreas
• Artificial Hips and Knees
• Artificial bladder/cardia/penis
• Not Prosthetic Arms and Legs
• Not Neural stuff

6. Artificial organs
• Life support to prevent imminent death
while awaiting a transplant (e.g. artificial
heart)
• Dramatic improvement of the patient's
ability for self care (e.g. artificial limb)
• Improvement of the patient's ability to
function socially (e.g. cochlear implant)
• Cosmetic - after cancer, surgery or an
accident.

7. Artificial Hearts
• An artificial heart is a prosthetic device that is
implanted into the body to replace the biological
heart.
• It is different from a heart bypass machine,
which is an external device (a CardioPulmanory
Bypass - CPB).
• A CPB is only suitable for a few hours use, while
artificial hearts have so far been used for periods
of well over a year.

8. Artificial Hearts
• Heart is basically a
pump, but with a
lot of subtleties.
• Lower the need for
transplants
• Foreign-body
rejection a
problem
• Right is Abiocor

9. Artificial Hearts
• 1963 – first patented device (Uni Utah)
• 1982 – first patient 61-year-old Barney
Clark, survived for 112 days
• 2001 – Abiocor, self-contained, approved
for human use - the longest implantation
so far is 602 days (20.4 months).
• Main use is still for folk waiting for a
transplant

10. CardioPulmonary Bypass (CPB)
• Temporarily takes over the function of the
heart and lungs during surgery,
maintaining the circulation of blood and
the oxygen content of the body. Referred
to as a Heart-Lung Machine
• Oxygenator was first described by Robert
Hooke in the 17th Century – removes
carbon dioxide, injects oxygen to/from
blood

11. Iron Lung
• A large machine that enables a person to breathe when
muscle control has been lost or is poor.
• Person is in the centre of a steel drum. Head and neck
external. Drum forms an air-tight compartment enclosing
the person's body. Pumps periodically decrease &
increase the air pressure. When the pressure falls below
that within the lungs, the lungs expand and air from
outside the chamber is sucked in via the nose to keep
the lungs filled; when the pressure rises above that
within the lungs, the reverse occurs, and air is expelled.
In this manner, the iron lung mimics the normal action of
breathing.

12. Iron Lung

13. Iron Lung
• Not exactly portable
• Is it Bionic?
• No portable/replacement form available
• External ventilators for asthma sufferers +
oxygen tanks for divers etc – but are
these Bionic?
• What about other artificial organs?

14. Artificial Kidneys
• A portable, self-contained artificial kidney
has not yet been developed.
• A dialysis machine is a critical life support
device that completely replaces the duties
of a kidney – like an Iron Lung, it is a
separate machine.
• Dialysis machine is used as a temporary
measure, because of a disease or for a
person waiting for a kidney transplant.

15. Dialysis Machine
• Doesn’t treat the disease – merely a life support
system
• Via a membrane, restores levels of minerals such
as sodium and chloride, and bicarbonates to
expected levels in blood flow.
• Removes potassium, acid and urea from the
blood. (waste products)
• Replicates effects of kidneys

16. Dialysis Machine

17. Pancreas
• The pancreas is below the stomach and
above the duodenum. It releases
endocrine hormones (insulin, amylin and
glucagon) into the portal vein, where it
flows directly to the liver.
• Diabetes is the inability of the beta cells of
the pancreas to produce sufficient insulin.

18. Artificial Pancreas
• Helps diabetics control their blood glucose level
by providing the substitute endocrine
functionality of a healthy pancreas.
• The lack of insulin production is the motivation
to develop a substitute.
• Insulin replacement therapy is appreciated for its
life-saving capability, but manually managing the
blood sugar level with insulin alone is arduous
and inadequate.

19. Artificial Pancreas
• Different approaches under consideration:
• Medical equipment approach - using an insulin pump
under closed-loop control using real-time data from a
continuous blood glucose sensor. (nearly there)
• The biotechnology approach - the development of a bio-
artificial pancreas. When surgically implanted, the device
will behave as the original pancreas and will be viable for
years. (Speculation)
• The gene therapy approach - the therapeutic infection of
a diabetic person by a genetically engineered virus which
causes a DNA change of intestinal cells to become
insulin-producing cells. (Speculation)

20. Artificial Pancreas
• The Insulin pump is
used to automatically
deliver basal insulin
continuously, and
bolus insulin at meal
times by pressing the
buttons. Before meals,
a blood glucose value
is entered into the
pump to calculate the
correction bolus to
bring the blood
glucose level back to
the target value

21. Artificial Pancreas – present day
• An insulin pump to infuse a rapid acting insulin is the
first step in simulating the function of the pancreas. The
pump can deliver small increments of insulin compared
to an injection, and its controls match the insulin profile
required for a given situation. The pump is controlled
manually on command based on a snap shot of the
recent blood glucose level and an estimate of the
carbohydrate consumed. This approach is open-loop.
Once a bolus has been calculated and delivered, the
pump continues to deliver its basal rate insulin in the
manner that has been programmed.
• While insulin replacement is a life saving therapy, its
practical use in controlling blood glucose levels
sufficiently to avoid long term complications is not ideal.
• It is a therapy!!!

22. Artificial Urinary Bladder
• In 2006 the world's first lab-grown organ, a bladder, was
transplanted into a human. The bladders are grown from
a small sample of the patients' own bladder tissue, no
risk of rejection. Traditionally, damaged bladders are
stitched back together using other tissue from the
stomach or intestine.
• A CT scan of the patient is taken, to determine the
shape of the bladder that must be created. A tissue
sample is taken from the patient's bladder. These cells
are grown (takes 4 weeks), and then layered onto a
scaffold in the shape that the required bladder is to take.
The transplant procedure then takes place. The entire
bladder along with the scaffold is transplanted. The
biodegradable scaffold degrades within the patient's
body.

23. Artificial Cardia
• Sounds like the heart – but no.
• This relates to gastric repairs, specifically of the
valves at either end of the stomach.
• The cardia prevent the refulgence of stomach
contents into the esophagus.
• Artificial cardia consist of metallic and macromolecule
materials
• Simply used as replacements where disease has
taken the originals.
• Very few such operations even now have been
carried out

24. Artificial Corpora Cavernosa
• For erectile disfunction, both corpora cavernosa
can be irreversibly surgically replaced with
manually inflatable penile implants. This is a
drastic therapeutic surgery meant only for men
suffering from complete impotence that has
resisted all other treatment approaches.
• An implanted pump in the groin or scrotum can
be manipulated by hand to fill the artificial
cylinders, normally sized to be direct
replacements for the natural corpus cavernosa,
from an implanted reservoir in order to achieve
an erection.

25. Artificial Hips
• The most common reason for replacing the hip
joint is because of damage to the hip by
osteoarthritis. Other reasons include infection or
a fractured hip, which commonly occurs in older
women as a complication of osteoporosis or a
fall.
• The new joint is put in during a major operation
known as a total hip replacement (THR). About
35,000 THRs are carried out each year in
England and Wales on the NHS, and a
considerable number more in private hospitals.

26. Artificial Hips
• The joint consists of three parts:
• A metal ball (titanium alloy) that replaces the
top of the femur or leg bone.
• Attached to this ball is a metal stem, which is
inserted down into the centre space of the
femur. The metal ball and stem are stuck to the
bone using cement.
• A spherical plastic cup is inserted separately in
the bone of the pelvis. The metal ball of the
artificial hip joint is then pushed into this cup,
joining the leg and the pelvis. The ball can move
around in the cup, so the joint can bend and
move.

27. Artificial Knees
• www.goldsteinortho.com/knee.htm
• Illinois Bone and Joint Institute

28. Thoughts
• Mechanical replacements – knees/hips
• Organs still largely experimental or short
term – mainly transplants not implants
• Long way away from (artificially)
rebuilding or building a human body
• All therapeutic here – no enhancement
• Here we have avoided the brain/nervous
system – even more difficult

29. Final Thought
• Still a long way from Bionic people