2. Principles Of Electrocardiograph
Electrocardiograph – is the instrument that records the
electrical activity of the heart
Electrocardiogram (ECG) is the record of that activity
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3. ELECTRICAL ACTIVITY OF HEART
REPOLARIZATION
DEPOLARIZATION
R
P T
Q S
R
Tachycardia HR > 120bpm
Bradycardia HR < 40bpm
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4. P WAVE
Q WAVE
R WAVE
0.25mV
25% OF R WAVE
1.60mV
AMPLITUDE
T WAVE 0.1 TO 0.5 mV
DURATION
PR INTERVAL
ST INTERVAL
QRS INTERVAL
0.12 – 0.20 sec
0.35 – 0.44 sec
0.05 – 0.15 sec
0.09 sec
QT INTERVAL
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7. INSTRUMENTATION AMPLIFIER (AD620)
Gain equation:
Gain Set with One External Resistor (Gain Range 1 to 1000); 50mV Input
Offset Voltage; 100 dB min Common-Mode Rejection Ratio (G = 10); low
noise; 120 kHz Bandwidth (G = 100).
Make vs. Buy
SALIENT FEATURES
The AD620 is a low cost, high
accuracy instrumentation
amplifier that requires only one
external resistor to set gains of
1 to 10,000. Furthermore, the
AD620 features 8-lead SOIC
and
DIP packaging that is smaller
than discrete designs and
offers
lower power (only 1.3 mA max
supply current), making it a
good fit for battery-powered,
portable (or remote)
applications
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8. ISOLATION CIRCUIT
Isolation is realized in the following technologies:
•Transformer isolation
•Opto-isolation.
Complete galvanic separation between the input
stage (patient) and the remaining part of the measure
equipment.
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9. AD705 &TL082
APPLICATIONS
Low Frequency Active Filters
Precision Instrumentation
Precision Integrators
PRODUCT DESCRIPTION
The AD705 is a low power bipolar op amp that has the low input
bias current of a BiFET amplifier but which offers a significantly
lower IB drift over temperature. The AD705 offers many
of the advantages of BiFET and bipolar op amps without their
inherent disadvantages
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10. FILTERS
ANALOG
FILTER
DIGITAL
FILTER
PASSIVE
FILTER
ACTIVE
FILTER FIR
FILTER
IIR
FILTER
C
+
+
v+
vi
o R1
R2
+
1Ω
+
vo
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11. CIRCUIT MAKER
WHAT IS
CIRCUIT
MAKER?????
WHY SHOULD
WE USE CIRCUIT
MAKER
CIRCUIT MAKER IS A POWERFUL TOOL
TO SIMULATE ALL ELECTRIC CIRCUITS.
WE CAN SEE TIME AND FREQUENCY
RESPONSE OF CIRCUITS.
IT IS VERY EASY TO USE.
ALL ESSENTIAL COMPONANT ARE
AVAILABLE
NO REQUIRMENT OF PHYSICAL
INSTRUMENT.
TROUBLESHOOTING IS VERY EASY.
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12. ECG CIRCUIT ON CIRCUIT MAKER
Source & lead AD620 AMP. FILTER
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13. EAGEL PCB DESIGN SOFTWARE
EAGEL IS A PCB DESIGN SOFTWARE
IT IS USED TO REDUCE COMPLEXITY
IN PCB DESIGNING BECAUSE IT
GIVES OPTIMUM DESIGN
BY USING EAGEL WE CAN DESIGN 2
LAYER TO 16 LAYERS PCB.
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