An artificial heart is a mechanical device that replaces a failing heart. It has several valves and chambers to propel blood through the body. Artificial hearts can temporarily assist a recovering heart or permanently replace a damaged heart until transplant. Research is ongoing to reduce artificial heart sizes and develop implantable batteries and biologically compatible materials. Artificial heart valves also help damaged valves and come in mechanical and animal tissue forms, each with advantages and disadvantages. Future areas of research include polymer and tissue engineered valves.

1. ARTIFICIAL HEART
Ahmed Abdelfatah Hussien
Biomechatroni
cs

2. Introduction
DEFINITION
“An artificial organ is a
man-made device that is
implanted into the human
body to replace one or
many functions of a natural
organ, which usually are
related to life support.”
An artificial heart is a
mechanical device, about
the size of an orange, that
is connected to your heart
or implanted in your chest
to help or replace a failing
heart. It may have several
valves, a mechanism to
propel blood forward, and
one or more chambers.

3. Sometimes an artificial heart may help your heart temporarily, until yours
recovers. If this is the case, the artificial heart will be removed when it is
no longer needed. More commonly, when there is irreversible heart
muscle damage and your heart can t recover, the artificial heart stays
until you can have a heart transplant. If no other options are available, an
artificial heart may completely and permanently replace your heart.

4. Human Heart
Heart consists of:
Right Atrium and Ventricle Atrium
Left Atrium and Ventricle
Two Types of Valves:
Atrioventricular Valve:
separates the atrium from the
ventricle
Semi-Lunar Valve:
separates the ventricles from the
outgoing blood vessels

5. Human Heart
Right Atrioventricular Valve:
Tricuspid Valve
Left Atrioventricular Valve:
Bicuspid Valve
Right Semi-Lunar Valve:
Pulmonary Valve
Left Semi-Lunar Valve:
Aortic Valve
Purpose of Valves: Prevent backflow,
or flow of blood back into chamber
from which it came

6. Human Heart
Heart Function:
 When the heart is at rest the right atria is filled
with oxygen free blood returning from the
body. While the left atrium receives oxygen
rich blood from the lungs.
 After the atria fill an electrical impulse causes
them to contract forcing open valves that lead
to the ventricles.
 The same electrical impulse causes the
ventricles to contract about a tenth of a
second later pushing the blood through
another set of valves that lead to the lungs
and the rest of the body.

7. History
1972- Robert Jarvik created the 1st human artificial
heart made of polyester, plastic, & aluminum. It was
implanted in cows.
1981- The 1st artificial heart was approved for human
implantation. (Jarvik-7)
1982- Barney Clark received the 1st implantation
performed by William DeVires of the University of Utah
1994- The FDA approved the Ventricular Assist Device
(VAD) which was the 1st wearable device to assist the left
ventricular
2004- The 1st Total Artificial Heart (TAH) was approved
by the FDA by Cardio West.

8. Jarvik-7 Artificial Heart
 The Jarvik-7 design incorporates two heart
pumps that are connected to a power console.
 Each pump is small enough to be implanted into
the void that was left behind from the extraction.
 Both pumps receive power from a large
external console. The console pushes air
through the tubing.
 Air enters inside the pump and is expelled
through a series of thin flexible diaphragms.
 The doctors monitor the patients cardiac output
and heart rate from a power console a seven
feet away from where the patient rests.

9. AbioCor Artificial Heart
Patients with an implanted AbioCor
heart will still have atria that beat at the
same time, but the artificial heart, which
replaces both ventricles, can only force
blood out one ventricle at a time. So, it
will alternately send blood to the lungs
and then to the body, instead of both at
the same time as a natural heart does.
The AbioCor is able to pump more
than 10 liters per minute, which is
enough for everyday activities.

10. What research is being done into
artificial hearts?
Research is being done in several areas to improve the quality and use of artificial hearts.
 Researchers are looking into reducing the size of artificial hearts so that they can be
totally implanted inside the chest.
 Work is also being done to develop artificial heart batteries that are small, long-lasting
and implantable, and which can be recharged across the patient s skin.
 Biologically superior materials are being developed to reduce the tendency for blood to
clot and the need for blood-thinning medicines (anticoagulants). These materials will be
used to line the internal chambers of artificial hearts.
 Research is also being done into stem cells, which may be used to replace damaged
heart muscle cells and restore heart muscle function. If this is possible, it would prevent
heart failure and ultimately reduce the need for heart transplants and artificial hearts.

11. Artificial Heart valve
 An artificial heart valve is a
mechanism that mimics the function
of a human heart valve
 It’s used for patients with a heart
valvular disease or have a damaged
valve
 Heart valves are used to provide the
heart with a unidirectional blood flow

12. When Heart Valves Stop Working
 Heart Valve diseases fall into two categories:
stenosis- hardening of the valve
incompetence- permittence of backflow
3 causes of Heart Disease:
 Rheumatic Fever: stiffens valve tissue,
causing stenosis
 Congenitally defective valves: do not form
properly as the heart develops, but often go
unnoticed until childhood
 Bacterial infection: causes inflammation of
valves, tissue scarring, and permanent

13. Artificial Heart Valve Types

14. Evolution of Prosthetic Heart Valves
 The development of the original
ball-and-cage valve design can be
attributed to the bottle stopper in
1858
 In the early 1950’s, it led to the
idea of a prosthetic heart valve
consisting of a cage with a mobile
spherical poppet

15.  This first heart valve was made
of a Plexiglass(methyl
methacylate)cage surrounding
a silicone-coated nylon poppet
 First implanted in a human in a
closed procedure in September
of 1952 (descending thoracic
aorta)
Evolution of Prosthetic Heart Valves

16.  Significant advances were made soon after to help the
development of the heart valve:
In 1953, marked successful use of the heart and lung
machine, paving the way for the 1st open heart
operations
The idea of using blood from another patient to
oxygenate the blood of the patient was developed
New methods were came for evacuating air from the
heart
New materials (Plexiglass, Teflon, and Dacron)
Evolution of Prosthetic Heart Valves

17.  On July 22, 1955, at the City General Hospital in
Sheffield, England, Judson Chesterman implanted the
first successful heart valve
 The patient lived 14 hours after the valve was placed,
but died when the poppet twisted out of position
 Valve was made of Perspex, an outer cage, a poppet,
and 2 buttons to fasten the valve to the outside of the
heart
Evolution of Prosthetic Heart Valves

18.  Starr-Edwards valve was first
successful long-term valve
created
 It was implanted in its first 8
patients in 1961 (6 of 8 survived
 Ball-and-Cage design
 Devised important “Nine
Commandments” in developing a
prosthetic heart valve
Evolution of Prosthetic Heart Valves

19. “Nine Commandments”:
 Embolism Prevention
 Durability
 Ease and Security of Attachment
 Preservation of Surrounding Tissue Function
 Reduction of Turbulance
 Reduction of Blood Trauma
 Reduction of Noise
 Use of Materials Compatible with Blood
 Development of Methods of Storage and Sterilization
Evolution of Prosthetic Heart Valves

20.  Since this time, over 30
mechanical heart designs have
been marketed in the U.S. and
abroad
 These valves have progressed
from the simple caged ball
valves, to strut-and-leaflet valves
and the modern bileaflet valves,
to human and animal tissue
Evolution of Prosthetic Heart Valves

21. Mechanical Valves:
Ball Valves
This design uses a spherical occluder,
or blocking device, held in place by a
welded metal cage
Problem and Why failed: Natural heart
valves allow blood to flow straight
through the center of the valve
(central flow)
Caged-ball valves completely blocked
central flow and collisions with the
occluder ball caused damage to
blood cells
Finally, these valves stimulated
thrombosis, or formation of blood
clots

22. Starr-Edwards Ball Valve
Model: Starr-Edwards
Type: Aortic Caged Ball
Materials: Silicone Rubber ball with
2% barium sulfate, cage-Stellite
alloy No. 21, sewing ring- knitted
Teflon and polypropelene cloth
1 of 4 Starr-Edwards models
developed are still used today, and
is the only ball valve currently
used in U.S.

23. Magovern-Cromie Ball Valve
Model: Magovern-Cromie
valve
Type: Aortic Caged Ball
Materials: Ball-Silicone rubber
with barium, cage-titanium,
sewing ring-none, Cage
open at top

24. Smeloff-Suttor Ball Valve
Model: Smeloff-Suttor valve
Type: Aortic, Mitral, Tricuspid caged
ball
Materials: Ball-Silicone rubber,
cage-titanium, sewing ring-Teflon
Problems: Ball Variance, swelling of
ball from lipid absorbtion, can
cause sticking of ball in inflow
orifice

25. Mechanical Valves:
Single Leaflet Disc Valves
 Uses a tilting occluder disk to
better mimic natural flow patterns
through the heart
 tilting pattern allow more central
flow while still preventing backflow
 Some damage still occurs to blood
cells
 Reduces thrombosis and infection,
but does not eliminate either
problem

26. Mechanical Valves:
Single Leaflet Disc Valves

27. Bjork- Shiley Standard Aortic Valve
Model: Bjork- Shiley
Standard
Type: Aortic Tilting Disc
Materials: Disk- Pyrolytic
Carbon, cage-Haynes
25, sewing ring-Teflon

28. Medtronic-Hall Valve
Model: Medtronic-Hall
A7700 (aortic), M7700
(mitral)
Type: Aortic and Mitral
Tilting Disk
Materials: Cage-titanium,
Disk-Pyrolytic carbon,
sewing ring-knitted teflon

29. Other Single Leaflet Disc Valves
 Another similar valve is
the caged disc valve
 Examples are Starr-
Edward Model 6500 and
the Kay-Shiley Model

30. Mechanical Valves:
Bileaflet Disc Heart Valves
 Consists of two semicircular
leaflets that pivot on hinges
integrated onto the flange
 Carbon leaflets and flange exhibit
high strength and excellent
biocompatibility
 Provide closest approximation to
central flow
 Allows small amount of backflow
as leaflets cannot close completely

31. Mechanical Valves:
Bileaflet Disc Heart Valves

32. St. Jude Bileaflet Valve
Model: St. Jude Valve
Standard
Design :Mitral, Aortic,
Tricuspid Bileaflet Valve
Materials-Cage and disk-
pyrolytic carbon, sewing
ring-double velour
knitted polyester

33. Animal Tissue Valves
 Heterograft or Xenograft
Valves
 Most commonly used tissues
are the porcine (pig) valve
tissue and Bovine (cow)
pericardial tissue

34. Porcine (pig) Valves
 Two major brands of porcine
available today, Hancock and
Carpentier-Edwards
 Has good durability and and
good hemodynamics
Materials: Porcine valve tissue,
stents made of wire,
Elgiloy(cobalt-nickel alloy),
sewing ring-knitted Teflon

35. Pericardial (cow) Valves
 Lasts as long as standard
porcine valves at 10 years
 The pericardial valve has
excellent hemodynamics,
even in smaller sizes(19mm
to 21mm)and has gained a
large market share (about
40% of US tissue valves) in
this group of patients

36. Stentless Porcine Valve
 Stentless valves are made by
removing the entire aortic root
and adjacent aorta as a block
from the pig
 Drawbacks: Valve is more
difficult to implant and
requires special
measurements for successful
implantation

37. Homografts(Human to Human)
 Homografts are valves transplanted from one
human to another
 After donation, valves are preserved in liquid
nitrogen(cyropreserved) until needed
 Since the valve must be thawed overnight, the
patient’s size must be known beforehand
 As with heart transplants, homograft availability
is limited by donor availability

38. Autografts (Ross Procedure)
 Autografts are valves taken from the same patient in
which the valve is implanted
 Used for patients with diseased aortic valves
 Advantages: patient receives a living valve in the aortic
position
Better durability and hemodynamics
Disadvantages: difficult procedure for the surgeon and
involves considerable skill and time
most common problem is leakage of the valve (aortic
regurgitation)

39. Animal Tissue Valves vs. Mechanical Valves
 With the animal tissue, patients do not need lifelong anticoagulant
therapy required with mechanical valves
 Animal tissue is also inexpensive and mass-produced
 However, animal tissue has uncertain durability (5-15 years )that will
inevitably require a risky re-operation
 Mechanical valves can also fail suddenly and catastrophically
 Have serious problem with thromboembolism
 Tissue heart valves – Wear, there is a small possibility that the body
will reject the valve, inability to implant them into infants and
children
 Mechanical disadvantage- is cavitation, when the rapid change in

40. Algorithm for selecting a valve
procedure

41. Future of heart valve replacement
 Polymeric Heart Valves - Scientists are looking more
into polymer materials for heart valves because it’s
easy to fabricate, has a large range of polymer
properties, and durability.
 Tissue engineered heart valves- Obtaining the number
of types of cells for tissue valves, lack of scaffold
material
 Tissue engineered heart valves: better biocompatibility,
less infection, life expectancy of valve increase, To make
artificial heart valves compatible for children.