This document provides an overview of the EC601 Medical Electronics course, including: - The 5 units that will be covered: electro-physiology, biochemical measurement, assist devices, radiological equipment, and recent trends. - The course outcomes which include gaining knowledge about biopotentials, physiological parameters, assist devices, bio-signal transmission, and recent diagnostic techniques. - An introduction to the first unit which will cover the origin of bio-potentials, biopotential electrodes, biological amplifiers, recording methods, and typical waveforms like ECG, EEG, EMG, PCG, and EOG.

1. Topic: EC601 MEDICAL ELECTRONICS
10/31/2019
Assignment 2 (OER)
For Swayam MOOC course on
Academic Writing
Session: June-Nov 2019
Submitted by
E.Muthu Kumaran
(Student id: db0933b3eb4311e9bf755553a31156ad)
Email: reachemk@gmail.com

2. Content of presentation
10/31/2019 CC BY-SA-NC
• Introduction to the course Medical Electronics
(Sub code: EC601)
• Introduction on list of topics to be covered in 5
units.
• Suggested Books
• Generation of action potentials in unit 1

3. EC601
MEDICAL ELECTRONICS
• Unit 1
• Unit 2
• Unit 3
• Unit 4
• Unit 5
ELECTRO-PHYSIOLOGY AND BIO-POTENTIAL RECORDING
BIO-CHEMICAL AND NON ELECTRICAL PARAMETER
MEASUREMENT
ASSIST DEVICES AND BIO-TELEMETRY
RADIOLOGICAL EQUIPMENTS
RECENT TRENDS IN MEDICAL INSTRUMENTATION
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4. COURSE OUTCOMES (COs)
• To gain knowledge about bio-potentials and methods of
recording.
• To study about the various biochemical and non-electrical
physiological Parameters.
• To study about the various assist devices used in the
hospitals.
• To gain knowledge about the method of transmitting bio-
signals and equipment used for therapeutic applications.
• To understand the various recently developed diagnostic
and therapeutic Techniques.
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5. UNIT I
ELECTRO-PHYSIOLOGY AND BIO-
POTENTIAL RECORDING
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6. 1. ELECTRO-PHYSIOLOGY AND
BIO-POTENTIAL RECORDING
• The origin of Bio-potentials
• Biopotential electrodes
• Biological amplifiers
• Lead systems and recording methods, typical
waveforms and signal characteristics
ECG, EEG,
EMG, PCG,
EOG,
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7. UNIT II
BIO-CHEMICAL AND NON
ELECTRICAL PARAMETER MEASUREMENT
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8. 2.BIO-CHEMICAL AND NON ELECTRICAL PARAMETER
MEASUREMENT
• pH, pO2, pCO2, pHCO3
• Electrophoresis
• Colorimeter
• Photometer
• Auto analyzer
• Blood flow meter
• Cardiac output
• Respiratory measurement
• Blood pressure, temperature, pulse
• Blood cell counters
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9. UNIT III
ASSIST DEVICES AND
BIO-TELEMETRY
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10. 3. ASSIST DEVICES AND BIO-TELEMETRY
• Cardiac pacemakers
• DC Defibrillator
• Telemetry Principles
• Frequency Selection
• Bio-Telemetry
• Radio-Pill and Tele-Stimulation
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11. UNIT IV
RADIOLOGICAL EQUIPMENTS
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12. 4. RADIOLOGICAL EQUIPMENTS
• Ionosing radiation
• Diagnostic X-ray Equipments
• Use of Radio Isotope in Diagnosis
• Radiation Therapy.
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13. UNIT V
RECENT TRENDS IN MEDICAL INSTRUMENTATION
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14. 5. RECENT TRENDS IN
MEDICAL INSTRUMENTATION
• Thermograph
• Endoscopy Unit
• Laser in Medicine
• Diathermy Units
• Electrical Safety in Medical Equipment.
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15. Books
TEXT BOOK
• Leslie Cromwell, “Biomedical Instrumentation and
measurement”, Prentice hall of India, New Delhi, 1997.
REFERENCES
• Khandpur R.S, “Handbook of Biomedical Instrumentation”, Tata
McGraw-Hill, New Delhi, 1997.
• Joseph J.carr and John M. Brown, “introduction to Biomedical
equipment technology”, John Wiley and sons, New York, 1997.
• John G. Webster, “Medical Instrumentation Application and
Design”, John Wiley and sons, New York, 1998.
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16. Course Plan
• Each unit 9 hrs
• Internal Marks
– Viva 1 Unit 1 –> 5 marks (16th & 17th class)
– Viva 2 Unit 2 & 3 –> 5 marks (32nd & 33rd class)
– Viva 3 Unit 4 & 5 –> 5 marks (48th & 49th class)
– Attendance, Character,………. 4 marks
• Seminars, Mini project carries Extra points
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17. UNIT I
ELECTRO-PHYSIOLOGY AND BIO-
POTENTIAL RECORDING
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18. ELECTRO-PHYSIOLOGY AND
BIO-POTENTIAL RECORDING
• The origin of Bio-potentials
• Biopotential electrodes
• Biological amplifiers
• Lead systems and recording methods, typical
waveforms and signal characteristics
ECG, EEG,
EMG, PCG,
EOG,
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19. The origin of Bio-potentials
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20. Potential?
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21. • Measuring concentration between
two points.
• Electric Potential
Measuring Difference In Concentration of
Electrons Between Two Points
Bio Potential
Measuring Difference In
Concentration of Ions Between Two
Points
Ionic Potential
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22. What are biopotentials
Biopotential: An electric potential that is measured between
points in living cells, tissues, and organisms, and which
accompanies all biochemical processes.
• Also describes the transfer of information between and within cells
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23. Mechanism behind biopotentials
• Concentration of potassium (K+) ions is 30-50
times higher inside as compared to outside
• Sodium ion (Na+) concentration is 10 times
higher outside the membrane than inside
• In resting state the memberane is permeable
only for potassium ions
 Potassium flows outwards leaving an equal
number of negative ions inside
 Electrostatic attraction pulls potassium and
chloride ions close to the membrane
 Electric field directed inward forms
 Electrostatic force vs. diffusional force
• Nernst equation:
• Goldman-Hodgkin-Katz equation:
mVVm 100...70 
i,k
k
k o,k
cRT
V ln
z F c
 
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K i,K Na i,Na Cl i,Cl
m
k K i,K Na i,Na Cl i,Cl
P c P c P cRT
V ln
z F P c P c P c
 
 
 
mVVm 100...70 

24. Neuron Schematic
• Conduction along a
nerve
– result of depolarization
of small patch of
membrane
– conduction along a nerve
fiber (more generally
axons and dendrites)
– saltatory conduction
along myelinated fibers
in nerves, spinal cord
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25. (a) Charge distribution in the vicinity of the active region of an ummyelinated fiber conducting an
impulse. (b) Local circuit current flow in the myelinated nerve fiber.
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Cell
Node of Ranvier
Myelin
sheath
Active
node
Local closed (solenoidal)
lines of current flow
Repolarized
membrane
Axon
Resting
membrane
External medium
+

+

+

+

+

+

+

+


+

+

+

+
+

+

+

+

+

+

+

+


+

+

+

+

+

+

+

+

+

+

+
+

+

+

+


+

+

+

+

+

+

+

+
+

+

+

Active region
Depolarized
membrane
(a)
(b)
Direction of
propagation
Periaxonal
space
Axon + 

26. Measurement of neural conduction velocity via measurement of
latency of evoked electrical response in muscle. The nerve was
stimulated at two different sites a known distance D apart.
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Reference
Velocity = u =
2 ms
V°(t)
S2
S2
S1
S1
Muscle
+  + 
D
R
L2
L1 L2
L1
t D
V°(t)
V°(t)
1mV

27. Mechanism behind biopotentials
• Concentration of potassium (K+) ions is 30-50
times higher inside as compared to outside
• Sodium ion (Na+) concentration is 10 times
higher outside the membrane than inside
• In resting state the member is permeable only
for potassium ions
 Potassium flows outwards leaving an equal
number of negative ions inside
 Electrostatic attraction pulls potassium and
chloride ions close to the membrane
 Electric field directed inward forms
 Electrostatic force vs. diffusional force
• Nernst equation:
• Goldman-Hodgkin-Katz equation:
mVVm 100...70 
i,k
k
k o,k
cRT
V ln
z F c
 
10/31/2019 CC BY-SA-NC
K i,K Na i,Na Cl i,Cl
m
k K i,K Na i,Na Cl i,Cl
P c P c P cRT
V ln
z F P c P c P c
 
 
 
mVVm 100...70 

28. 10/31/2019 CC BY-SA-NC
Resting Potential - Both Na+ and K+ channels are closed.

29. 10/31/2019 CC BY-SA-NC
Initial Depolarization - Some Na+ channels open. If enough
Na+ channels open, then the threshold is surpassed and an
action potential is initiated.

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Na+ channels open quickly. K+ channels are still closed.
PNa+ > PK+

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Na+ channels self-inactivate, K+ channels are open.
PK+ >> PNa+

32. 10/31/2019 CC BY-SA-NC
Emembrane ≈ E K+
PK+ > PK+ at resting state

33. Generation of an Action Potential
• Depolarization: Due to opening of voltage gated Na+ As
the outside of the cell has become more negative than
the inside of the cell
• Repolarization: the return to polarization due to the
closing voltage-gated Na+ channels and the opening of
voltage gated K+ channels
• Refractory period: the time during membrane
repolarization when the muscle fiber cannot respond to a
new stimulus (a few milliseconds)
1. Absolute 2. Relative
• All-or-none response: once an action potential is initiated
it results in a complete contraction of the muscle cell
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34. Refractory Period
There are two types of
refractory period:
Absolute Refractory Period –
Na+ channels are
inactivated and no matter
what stimulus is applied
they will not re-open to
allow Na+ in &
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CC BY-SA-NC
depolarise the membrane to the threshold of an
action potential.
Relative Refractory Period - Some of the Na+ channels have
re-opened but the threshold is higher than normal making it
more difficult for the activated Na+ channels to raise the
membrane potential to the threshold of excitation.

35. Thank You
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