2. Objectives
• What is cardiac pacemaker ?
• History of cardiac pacemaker
• When are pacemaker used ?
• Types of cardiac pacemaker
• Pacemaker circuit
• Cardiac pacemaker design
• Procedure during the pacemaker implanted
• Technical specification of a pacemaker
• Advantage and Disadvantage of pacemaker-
• Conclusion
• Reference
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3. What is cardiac pacemaker ?
• A pacemaker is a small device that's placed in the chest or
abdomen to help control abnormal heart rhythms. This
device uses electrical pulses to prompt the heart to beat at a
normal rate.
• Pacemakers are used to treat arrhythmias . Arrhythmias are
problems with the rate or rhythm of the heartbeat. During
an arrhythmia, the heart can beat too fast, too slow, or with
an irregular rhythm.
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4. History of cardiac pacemaker-
In
1932 Albert Hyman
Concept of artificial
pacemaker,
magneto-generator
to power up
electrode.
In
1950 john Hopps
1st trans-cutaneous
pacemaker.Vaccum
tube technology &
direct AC power
supply is used.
In
1958 Dr.Ake senning
1st implanted (trans-
venous) pacemaker.
In
1959 W.M Chardack
1st successful long
term implantable
pacemaker.
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5. When are pacemaker used ?
• Pacemakers may be prescribed for a number of condition,including :
• Bradycardia - A condition in which the heart beats too slowly.
• Atrial fibrillation – A common heart rhythm disorder in which the heart
beats too fast and chaotically. Which disorder can be treated by
pacemaker.
• Heart failure – A condition in which the heartbeat is not strong enough
to carry a normal amount of blood and oxygen to the brain and other
parts of the body.
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6. Types of cardiac pacemaker-
• The pacemaker’s primary function is the heart its secondary function is
sensing for intrinsic signals.Pacemaker can be categorized in several
ways- they can be defined with a code of three letters or they can be
unipolar , bipolar, single-chamber , dual-chamber pacemaker.
• First , we will discuss the codes used to define different types of
pacemakers-
Single chamber pacemaker
Dual chamber pacemaker
Biventricular pacemaker
Rate responsive pacemaker
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7. Types of cardiac pacemaker-
• Single chamber pacemaker have one wire that is placed in
the right upper chamber (atrium) or lower chamber (ventricle).
• Dual Chamber pacemaker have two wires, one in the atrium and
one in the ventricle.
Fig : Single chamber pacemaker Fig : Dual chamber pacemaker
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8. Types of pacemaker-
• Biventricular pacemaker have three wires , one is in the right
atrium , one in the right ventricle and a third in the left ventricle. This
pacemaker used to improve pumping in patients with heart failure.
• Rate responsive pacemaker adjust rate to a patient’s level of activity.
They pace faster when a patient is exercising and slower when a
patient is resting.
Fig : Biventricular pacemaker
Fig : Rate responsive pacemaker
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9. Pacemaker Circuit-
• A pacemaker has three components :
This is kept in small metal case and the circuit is connected to a battery. The circuit
generates the impusle at a specific time.
These insulated wires carry the impusle to the heart.
This is kept in the hospital or clinic to program the pacemaker and to adjust the setting of
impulse amplitudes and frequency. The programmer is a specialized computer with a
hardware and software interface.
1.Pacemaker electronic circuit
2. Pacing leds
3. Programmer
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11. Cardiac pacemaker design-
• They are packaged in hermetically (airtight) sealed metal packages.
• Titanium
• Stainless steel
• Power supply : Currently Lithium Iodide batteries are used
• Increased life time
• Open circuit voltage of 2.8 V.
• Highly reliable
• Relatively High source resistance is a major limitation
Timing Circuit : Advanced pacemakers have timing circuits to determine when
a stimulus should be applied to the heart.
Output Circuit/Pulse Generator : Produces the actual electrical
stimulus that is applied to the heart.
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12. Cardiac pacemaker design-
• Generates an electrical stimulus pulse that has been optimized for
stimulating the myocardium through the electrode system that is being
applied with the generator.
• Constant-voltage or constant-current amplitude pulses are the two usual
types of stimuli produced by the output circuit.
• Output Circuit : Constant-voltage amplitude pulses are typically in the
range of 5.0 to 5.5 V with a duration of 500 to 600 µs. Pulse rate range 70
to 90 beats per minutes.
• Lead Wires : Must be mechanically strong. Must maintain good electrical
insulation to prevent the possibility of shunting important stimulating
current away from its intended point of application on the heart.
• Electrodes : Can be placed on the external surface of the heart
(epicardial electrodes). Made of materials that do not dissolve during long
term implantation.
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13. Procedure during the pacemaker implanted-
Generally, a pacemaker insertion follows this process:
You will be asked to remove any jewelry or other objects that may interfere
with the procedure.
You will be asked to empty your bladder prior to the procedure.
An intravenous (IV) line will be started in your hand or arm prior to the
procedure for injection of medication and to administer IV fluids, if needed.
You will be connected to an electrocardiogram (ECG or EKG) monitor that
records the electrical activity of the heart and monitors the heart during the
procedure using small, adhesive electrodes.
Large electrode pads will be placed on the front and back of the chest.
Once the lead wire is inside the heart, it will be tested to verify proper location
and that it works. There may be one, two, or three lead wires inserted,
depending on the type of device your doctor has chosen for your condition
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14. Procedure during the pacemaker implanted-
The ECG will be observed to ensure that the pacer is working correctly.
The skin incision will be closed with sutures, adhesive strips, or a special glue.
A sterile bandage or dressing will be applied.
Figure :
Location of
pacemaker
implant
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15. Technical specification of a pacemaker-
Pacing Modes VVI,VVT,VVO,AAI,AOO,OFF
Basic Pacing rates Between 30bpm and 120bpm
Sensitivites Between 0.5mv and 4.0mv ,in step of 0.5mv
Electrical configuration for pacing Monopolar/bipolar
Initial voltage 2.8v
Electrode material Titanium coated with iridium oxide.
Lead body Polyurethene
Means of attachment Titannium alloy screws
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16. Advantage and Disadvantage of pacemaker-
ADVANTAGE
The pacemaker uses electrical impulse
to stimulate faster rate when the natural
system of heart falling to regulate heart
beat pacing.
For biventricular pacemaker, its work to
ensure the ventricle and atria to work
together and improve the heart
pumping efficiency.
Used to rectify that causes the heart
ventricle to quiver instead than beat in
normal rhythm.
By using pacemaker the heart failure
can be prevent by coordinate electrical
signal between ventricles of the heart.
DISADVANTAGE
Pacemaker implantation may reveal
patients to surgical site infections. Apart
from that they can get allergic to
anesthesia and also became swollen and
bruising.
The pacemaker users have to be careful
with electrical appliances such as cell
phone, microwave oven and also high
tension wire.
Not only routines that need to be taken
into account, but they must also be wary
of medical equipment, such as MRI with
very high magnetic forces and shockwave
lithotripsy to get rid kidney stones.
All these can disrupt the electrical
signalling of pacemaker and stop it from
functioning and can cause fatal.
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17. Conclusion-
• The artificial pacemaker has been around for over
50 years. Technology has allowed us to advance
tremendously int he field of medicine. Today
engineers are find ways for creating longer lasting
batteries and a way to develop a and replace the
actual pacemaker located in our bodies now. With
these advances in technology, artificial pacemakers
are changing the lives of thousands every year.
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18. Reference-
• Handbook of Biomedical Instrumentation,R S
khandpur,Tata McGraw-Hill,2003.
• http://www.hopkinsmedicine.org/healthlibrary/test
_procedures/cardiovascular/pacemaker_insertion
_92,P07980
• https://www.nhcs.com.sg/patientcare/ConditionsA
ndTreatments/Pages/CardiacPacemakerImplanta
tion.aspx
• Basic principal of cardiac pacemaker Technology,
D. Korpas, Implantable Cardiac Devices
Technology, Springer Science+Business Media
New York 2013.
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