1. MEDICAL ELECTRONICS Mr. DEEPAK P. Associate Professor ECE Department
SNGCE
MEDICAL ELECTRONICS
Mr. DEEPAK P.
Associate Professor
ECE Department
SNGCE
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DEEPAK P

2. SNGCE
UNIT 3
ECG, EMG, Telemetry
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3. EEG
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4. Electroencephalography (EEG)
Electroencephalography (EEG) is the recording of electrical activity along the scalp.
EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain.
Electroencephalogram (EEG) was first measured in humans by Hans Berger in 1929.
EEG is most often used to diagnose epilepsy, which causes abnormalities in EEG readings.
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5. Electroencephalography (EEG)
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6. Electroencephalography (EEG)
It is also used to diagnose sleep disorders, coma, and brain death
Among the basic waveforms are the alpha, beta, theta, and delta rhythms.
Alpha waves occur at a frequency of 8 to 12 cycles per second in a regular rhythm.
They are present only when you are awake but have your eyes closed.
Usually they disappear when you open your eyes or start mentally concentrating.
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7. Electroencephalography (EEG)
Beta waves occur at a frequency of 13 to 30 cycles per second.
They are usually associated with anxiety, depression, or the use of sedatives.
Theta waves occur at a frequency of 4 to 7 cycles per second.
They are most common in children and young adults.
Delta waves occur at a frequency of 0.5 to 3.5 cycles per second.
They generally occur only in young children during sleep.
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8. Electroencephalography (EEG).
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9. Electroencephalography (EEG).
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10. Electroencephalography (EEG).
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11. Evoked Potentials .
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12. Electroencephalography (EEG)
EEG machine consists of the following components
1- Electrodes.
2- Amplifiers.
3- Filters.
4- Recording unit.
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13. Analog EEG
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14. Digital EEG
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15. EEG Electrodes
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16. EEG Electrodes There are two system of electrode placement:
international system: includes 21 electrodes.
international system: includes 64 electrodes.
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17. EEG Electrodes
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18. EMG
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19. Electromyogram (EMG)
Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by skeletal muscles.
EMG is performed using an instrument called an electromyograph
An Electromyograph detects the electrical potential generated by muscle cells when these cells are electrically or neurologically activated
Measured EMG potentials range between less than 50 μV and up to 20 to 30 mV, depending on the muscle under observation.
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20. Electromyogram (EMG)
An electromyogram (EMG) measures the electrical activity of muscles at rest and during contraction.
Nerve conduction studies measure how well and how fast the nerves can send electrical signals.
Body temperature can affect the results of this test.
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21. Electromyogram (EMG)
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22. Electromyogram (EMG)
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23. Electromyogram (EMG)
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24. Electromyogram (EMG)
EMG is used clinically for the diagnosis of neurological and neuromuscular problems.
There are two kinds of EMG in widespread use:
Surface EMG
Intramuscular (needle and fine-wire) EMG.
A surface electrode may be used to monitor the general picture of muscle activation
To perform intramuscular EMG, a needle electrode or a needle containing two fine-wire electrodes is inserted through the skin into the muscle tissue.
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25. Electromyogram (EMG)
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26. Electromyogram (EMG)
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27. Simple Block diagram (EMG)
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28. pre-amplifier
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29. Properties of an ideal pre-amplifier
High common mode rejection ratio
Very high input impedance
Short distance to the signal source
Strong DC signal suppression
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30. Analog EMG Block diagram
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31. Digital EMG Block diagram
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32. Digital EMG Block diagram
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33. Bed -Side Monitor 33
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34. Patient Monitoring
In medicine, monitoring is the observation of a disease, condition or one or several medical parameters over time.
It can be performed by continuously measuring certain parameters by using a medical monitor
Transmitting data from a monitor to a distant monitoring station is known as telemetry or biotelemetry.
Vital signs (often shortened to just vitals) are used to measure the body’s basic functions
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35. Patient Monitoring
Vital measurements are taken to help assess the general physical health of a person, give clues to possible diseases.
There are four primary vital signs: body temperature, blood pressure, pulse (heart rate), and breathing rate (respiratory rate).
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36. Patient Monitoring in ICU
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37. Simple Block Diagram of Patient Monitoring
Automatic
control
Patient
equipment
Computer
DBMS
Reports
Mouse and
keyboard
Display
Transducers
Clinician
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38. Bed-Side Monitor
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39. Measuring Parameters
Cardiac monitoring: Electrocardiography Cardiac output
Hemodynamic blood pressure and blood flow
Respiratory monitoring: Pulse oximetry,Capnography, airway respiratory rate)
Blood glucose monitoring
Childbirth monitoring
Body temperature monitoring
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40. Central Monitor 40
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41. Central Monitoring Bedside Monitors Physiological data
Hard wire Remote Link
From other beds
Central Monitor Console
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42. Central Monitoring
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43. Bio Telemetry 43
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44. Bio-Telemetry
The term telemetry is derived from the two Greek terms: “tele” and “metron”, which mean “remote” and “measure”.
In general, a physical variable or quantity under measurement, whether local or remote, is called a measurand.
Telemetry is a technology that allows the remote measurement and reporting of information of interest to the system designer or operator.
Literally, biotelemetry is the measurement of biological parameters over a distance.
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45. Elements of Telemetry
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46. Elements of Telemetry Transducer or Sensor:
Converts the physical variable to be telemetered into an electrical quantity.
Signal Conditioner-1:
Converts the electrical output of the transducer (or sensor) into an electrical signal compatible with the transmitter.
Transmitter:
Its purpose is to transmit the information signal coming from the signal conditioner-1 using a suitable carrier signal to the receiving end.
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47. Elements of Telemetry
The transmitter may perform one or more of the following functions:
(i) Modulation: Modulation of a carrier signal by the information signal.
(ii) Amplification: As and if required for the purpose of transmission.
(iii) Signal Conversion: As and if required for the purpose of transmission.
(iv) Multiplexing: If more than one physical variables need to be telemetered simultaneously from the same location, then either frequency-division multiplexing (FDM) or time-division multiplexing (TDM) is used.
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48. Elements of Telemetry
Receiver: Its purpose is to receive the signal(s) coming from the transmitter (located at the sending end of the telemetry system) via the signal transmission medium and recover the information from the same.
It may perform one or more of the following functions:
Amplification
Demodulation:
Reverse Signal Conversion
De-multiplexing
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49. Elements of Telemetry
Signal Conditioner-2: Processes the receiver output as necessary to make it suitable to drive the given end device.
End Device: The element is so called because it appears at the end of the system.
End device may be performing one of the following functions:
Analog Indication:
Digital Display
Digital Storage
Data Processing
Closed-Loop Control
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50. Subsystems of Telemetry System
(a) Measurement Subsystem:
It comprises the transducer (or sensor), signal conditioner and the end device, like any conventional measurement system.
(b) Communication Subsystem:
It comprises the transmitter and receiver along with the transmission medium linking the two, like any communication system.
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51. Telemetry Classification Based on Transmission Medium
Wire-Link Telemetry or Wire Telemetry
Radio Telemetry or Wireless Telemetry
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52. Wired Telemetry
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53. Elements of Wired Bio-Telemetry(Analog)
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54. Elements of Wired Bio-Telemetry(Digital)
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55. Elements of Wired Bio-Telemetry
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56. Elements of Wireless Bio-Telemetry
A typical biotelemetry system comprises:
Sensors appropriate for the particular signals to be monitored
Battery-powered, Patient worn transmitters
A Radio Antenna and Receiver
A display unit capable of concurrently presenting information from multiple patients
It is two types
Short-Range Radio Telemetry
Satellite-Radio Telemetry
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57. Elements of Basic Wireless Bio-Telemetry
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58. Elements of Wireless Bio-Telemetry
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59. Wireless Bio-telemetry Transmitter
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60. Wireless Bio-telemetry Receiver
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61. Elements of Wireless Bio-Telemetry
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62. Telemetry Classification Based on Modulation Method
DC Telemetry Systems
1. Direct voltage telemetry system
2. Direct current telemetry system
AC Telemetry Systems
1. Amplitude modulation (AM) telemetry system
2. Frequency modulation (FM) telemetry system
Pulse Telemetry Systems
1. Pulse amplitude modulation (PAM) telemetry system
2. Pulse width modulation (PWM) telemetry system
3. Pulse phase modulation (PPM) telemetry system
4. Pulse frequency modulation (PFM) telemetry system
5. Pulse code modulation (PCM) telemetry system
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63. Direct Current Telemetry
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64. FM Radio Telemetry
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65. Single Channel PWM Telemetry
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66. Single Channel PCM Telemetry
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67. Portable Telemetry
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68. Portable Telemetry
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69. Cardiac Tachometer 69
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70. Tachometer Tachometer is generally used for measuring the speed
Tachometer can be classified in to
Analog Tachometer– It consists of needle and dial
Digital Tachometer-- It consists of memory, LCD and LED
Contact Tachometer–Sensor is directly contact with rotor
Non Contact Tachometer
Time/ Frequency measurement Tachometer
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71. Tachometer
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72. Applications Tachometer
It is commonly used in automobiles and machineries.
It is used in automobiles to indicate the rotation rate of crank shaft of engine.
Used to estimate the traffic speed of vehicles.
Used in medical field to measure the heart rate , blood flow rate, respiratory gas flow rate.
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73. Cardiac Tachometer
It senses the heart beat from finger tip using IR reflection method
When heart contracts, the volume of blood in the finger tip decreases.
When heart expands, the volume of blood in the finger tip increases.
The resultant pulsing of blood volume inside the tip is proportional to heart rate.
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74. Cardiac Tachometer
IR TX-RX pair is placed in finger tip with close contact.
The reflected IR wave is sensed by the circuit.
The intensity of the reflected wave is proportional to the volume of blood in the finger tip.
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75. Block Diagram of Cardiac Tachometer
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76. Cardiac Tachometer
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77. IR Sensor
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78. Cardiac Tachometer
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79. Cardiac Tachometer
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80. Cardiac Tachometer
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81. Cardiac Tachometer
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82. Cardiac Tachometer
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83. Cardiac Tachometer
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84. Cardiac Tachometer
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85. Alarms 85
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86. Comparator Alarm Circuits
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87. Alarm Circuits using Cardiac Tachometer
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88. Lead Fault Indicator 88
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89. Lead fault indicator
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90. Lead fault indicator
When a monitor electrode or lead wire comes loose, the appearance of display will be either a base line or 60Hz interface.
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