1. DEFIBRILLATOR MACHINE BAsic TECHNICAL TRAINING
By: Armando Darino Ngojo
Senior Biomedical Engr.

2. Contents Aims & Objectives Introduction Principle
Anatomy and Physiology
Application
Types
Operation
Safety
Maintenance
Troubleshooting
PPM
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3. Aims To provide basic understanding about the Defibrillator Machine
To perform and understand the basic technical troubleshooting steps and PPM tasks
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4. Objectives - as a result of completing this module, the biomedical technician / engineer should be able to:
understand the concept of the Defibrillator including its applications
perform and identify basic problems, errors and basic troubleshooting solutions.
Perform PPM tasks
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5. History
1899
Prevost and Batelli first introduced the concept of electrical fibrillation after  noticing that large voltages applied across the animal's heart could convert  ventricular fibrillation into a sinus rhythm.
1933
1950s
1956
Hooker, Kouwenhoven and Langworthy published an account of successful  alternating current (AC) internal animal defibrillation
Kouwenhoven was able to defibrillate dogs by applying the electrodes to  the chest wall, that was the external electric defibrillator.
Zoll defibrillated a human subject in the same manner .
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6. History
1960s
1970s
Edmark and Lown et al found that direct current (DC) or pulse defibrillators  were more effective and produced fewer side effects than AC defibrillator.  The DC pulse waveform was further improved.
Experimental internal and external devices were designed to automatically  detect ventricular fibrillation.
1980s
Present times
The first automatic internal defibrillator was implanted in human
A lot of improvements were introduced to the defibrillator with the aim of improving the survival rate of the cardiac arrested patient
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7. What is Defibrillator
- A device that reverses the Fibrillation of the heart.
Fibrillation causes the heart to stop pumping blood, leading to brain damage.
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8. Defibrillation
Defibrillation is a process in which an electronic device sends an electric shock to the heart to stop an extremely rapid, irregular heartbeat, and restore the normal heart rhythm.
It is a common treatment for life threatening cardiac dysrhythmia, ventricular fibrillation, and pulse less ventricular tachycardia.
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9. Principle
A high voltage electric current is applied to the Heart muscle either directly (Internal Defibrillator) through the open chest or indirectly (External Defibrillator) through the chest wall to terminate Ventricular Fibrillation.
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10. Physiology of Defibrillation
If enough current is delivered to the heart then a majority of Ventricular cells will be depolarized
A critical mass of cells should be simultaneously depolarized to achieve defibrillation
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11. Bio Electric Signal Polarization Potassium ions pumped in
Sodium ions pumped out
Depolarization
Potassium ions pumped out
Sodium ions pumped in
Repolarization
Bio Electric Signal
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12. Anatomy - Heart
Located between the lungs in the middle of chest, behind and slightly to the left of breastbone (sternum)
Size of ones fist and shaped like a cone.
An average heart pumps 2.4 ounces (70 milliliters) per heartbeat. An average heartbeat is 72 beats per minute. Therefore an average heart pumps 1.3 gallons (5 Liters) per minute.
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13. Cont… Heart is divided into four chambers Right Atrium Left Atrium
Right Ventricle
Left Ventricle
A wall of muscle called as a 'Septum', separates all chambers of heart.
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14. Normal Cardiac Conduction
Electrical pattern
ECG tracing
Explain the cardiac conduction pathways with the electrical impulse originating in the SA node (right atrium) which travels to the AV node (division of the right and left ventricles), down along the right and left bundle branches to the Purkinje fibers.
Intrinsic heart rates at the SA node are 80 bpm, the AV node is 60 bpm, and the ventricular rate (Purkinje fibers) is 40 bpm.
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15. Normal ECG tracing
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16. when
ABNORMALITIES
happen….
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17. 1. Ventricular Fibrillation
Ventricular Fibrillation is a very fast, irregular heart rhythm in the lower heart chambers (ventricles). During VF the heart quivers and pumps little or no blood to the body. Consciousness is lost in seconds. If not treated immediately, VF will cause sudden cardiac arrest
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18. Cardiac Arrest Occlusion of the coronary artery leads to ischemia.
Ischemia leads to infarct which causes interruption of normal cardiac conduction
Infarct = VF/VT
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19. SAMPLE SHOCKABLE RHYTHMS
Ventricular Fibrillation
Ventricular Tachycardia
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20. 2. Atrial Fibrillation
Atrial Fibrillation is a very fast, irregular heart rhythm in the upper heart chambers. During AF, the waveform is almost similar to normal waveform but for the loss of 'P' waveform.
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21. AF treatment:
For Atrial fibrillation, the shock should be avoided to be delivered in the T period otherwise it will lead to Ventricular Fibrillation
This is achieved by Synchronous mode
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22. Application Emergency department Anesthesiology Cardiology
Operation theatre
Intensive care areas
Ambulance services
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23. Types:
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24. 1. Manual
Clinical expertise is needed to interpret the heart rhythm and decide whether to charge the defibrillator and deliver the shock to patient. Energy selection and delivery is given to the patient manually.
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25. 2. Automatic
These defibrillators are small, safe, simple and lightweight with two pads that can be applied to the patient. The defibrillator guides the operator step-by-step through a programmed protocol. It records and analyses the rhythm and instructs the user to deliver the shock using clear voice prompts, reinforced by displayed messages.
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26. 3. External
External Defibrillator is the device which delivers the high energy shock to patients Heart externally on patient's chest by using a Defibrillator Paddle. The maximum energy deliver to the patient is about 360 Joules in Monophasic & 200 Joules in Biphasic Defibrillator.
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27. 4. Internal
Internal defibrillator consist of sterilized internal Handle/Paddle through which shock is delivered directly to the heart.
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28. 5. AED Automatic External Defibrillator
AED can be classified as either fully automatic or semiautomatic. In fully automatic models disposable paddles are kept connected to the patient whilst the AED analyzes the ECG rhythm , decides and determines whether a defibrillation counter-shock is needed. Then the device automatically charges and discharges. Semi Automatic AED analyze the patient's ECG and notify the operator when defibrillation is indicated. The operator then activates defibrillator and discharge.
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29. AED
Semi Automatic
Fully Automatic
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30. 6. ICD Implantable Cardioverter Defibrillator
If it detects an abnormally fast heart rhythm, it either electrically paces the heart very fast or delivers a small electrical shock to the heart to convert the heart rhythm back to normal. The rapid pacing is not felt by the patient but the electrical shock, if used, is felt as a strong jolt in the chest. The ICD is used to treat life-threatening heart rhythms that lead to sudden death.
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31. ICD
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32. 7. Pacemaker
A pacemaker is an electronic stimulator that produces periodic electric stimulation to the heart
It is classified into two types:
Internal Pacemaker
External Pacemaker
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33. Internal Pacemaker
Battery operated device that is implanted inside the patient’s body to pace the Heart
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34. External Pacemaker
This is used to pace the heart temporally. It may use leads or electrodes for the stimulation
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35. What is Joule? It is the unit of energy delivered by the Defibrillator
It means - “The energy released in one second by a current of one ampere through a resistance of one ohm”
Also called as watt-second
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36. - The delivered energy is in the range of 50-360 joules and depends on:
intrinsic characteristics of patient
patient’s disease
duration of arrhythmia
patient’s age
type of arrhythmia (more energy required for VF)
type of the machine used
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37. Operating Principle Monophasic Defibrillator Bi- Phasic Defibrillator
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38. Monophasic Defibrillator
Delivers its current in one forward direction (positive)
Requires higher escalating energy levels ( J) to convert VF/ pulse-less VT
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39. Bi Phasic Defibrillator
The Biphasic waveform type defibrillator delivers the current in one direction during the first phase and in opposite direction during the second phase.
Biphasic waveform shocks of 200 J are safe, equivalent or higher efficiency than damped sinusoidal waveform shocks of 360 J.
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40. Generation of bi-phasic waveform
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41. Waveform Comparison
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42. Operation Defibrillator: Normal and Synchronous Mode Monitor Recorder
Pacemaker
NIBP
SPO2
CO2
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43. 1. Manual Defibrillation
Switch 'ON' the Machine
Wait for initialisation and self test
Make sure it is not in SYNC Mode
Apply gel to the paddles
Place them properly on the chest
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44. Cont… Select 'ENERGY' to be delivered( energy in Joules)
Press 'CHARGE' button
Wait for Charging to complete. This is usually denoted by a continuous /long beep sound.
Apply pressure to the paddles ( 12 Kg of pressure)
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45. Cont… Make sure all the personnel are away from the patient
Press both 'DISCHARGE' button simultaneously
Observe patient and monitor ECG
If required, defibrillate again
When finished, turn off and clean the paddles
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46. 2. Synchronization Mode Wait for initialization and self test .
Connect ECG leads to get a tall R wave
Select 'SYNC / CARDIOVERSION' mode. .
Check for sync marker on the QRS waveform .
If possible sedate the patient and maintain airway
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47. Cont… Apply gel on the paddles and place it properly on chest
Select 'ENERGY' to be delivered( energy in Joules)
Press 'CHARGE' button
Wait for the Charge to be completed. This is usually denoted by a continuous /long beep sound.
Press both 'DISCHARGE' button simultaneously and hold till energy is delivered.
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48. Cont… Check patient condition and Heart rhythm.
If required, defibrillate again
Monitor the patient for few hours
Switch off and clean the paddles
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49. 3. Internal Defibrillation
Connect the Internal Paddles to the machine
Place one paddle over the apex of the left ventricles and the other over the base of the right ventricles
Switch on the machine
Select Energy
Charge and Discharge
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50. What are the types of Paddles?
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51. Paddle Placement
There are two notable methods of paddle placement recommended by AHA
Anterior- Anterior
Anterior-Posterior
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52. Paddle Placement Anterior- Anterior
Place one paddle near the second or the third right sternal border and the other on the cardiac apex.
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53. Paddle Placement Anterior-Posterior
- One paddle on sternum and the other on the left infra-scapular region
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54. Important Factors: 1.Time
Early defibrillation allows more success or the longer period of VF, the less success of defibrillation.
Early initiation of CPR improves the success rate
> 8 mins neurological damage sets in
> 10 mins survival probability becomes very low
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55. 2. Energy Level AHA Recommendation for Adults First shock 200 j
Second shock 200 j to 300 j
Third and above shocks 360 j
AHA Recommendation For Paeds
First shock 2 joules per Kg
Subsequent shock double the energy
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56. 3. Paddle Size Adult paddles should be 8 to 13 cm in diameter
Child paddles should be 4.5 cm in diameter
Infants use Anterior Posterior position
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57. 4. Skin To Paddle Interface
Use the right gel
Too little gel increases possibility of burn
Too much gel causes electric current to arc from one electrode to another
If disposable paddles are used check the expire date
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58. Block Diagram of a typical Defibrillator machine
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59. Power Supply Step up transformers used to convert 240 VAC to 5000 VAC
This is converted to DC by rectifier
In battery mode the DC is converted to AC by inverter
This AC is amplified and then again rectified to DC.
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60. Capacitor Most important part of Defibrillator
Stores large energy which can be discharged in a short burst
Unit of measurement is Farad
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61. Inductor
Coils of wire that produce a magnetic field when current flow through them
Used to prolong the duration of current flow
Unit of measurement is Henry
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62. Safety
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63. Safety - General
The Defibrillator generates High voltage. It must be operated by trained, professional and qualified personnel only.
Never use defibrillator with improper grounding or electrical leak socket.
Keep away the Defibrillator from any x-ray, Ultrasonic or other electronic instruments.
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64. Cont…
Check the patient lead wire, cable and paddles for any damage or mishandling, otherwise replace the same immediately.
Recommend using proper size and placement of recording paper.
Clean the print head regularly for clear printout
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65. Safety - Monitoring
Use only the specified patient cable as recommended by manufacturer.
Place the patient cable in proper winding position or hang on to patient cable arm attached with Defibrillator trolley
Use good ECG electrodes to monitor ECG waveform.
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66. Cont… Don't use damaged patient cable.
Confirm there is no ECG waveform because of electrical interference or defective patient cable. This may misinterpreted as QRS in synchronize mode.
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67. Safety - Defibrillation
Excessive Gels can cause arcing of the current along the chest wall
Malfunction of permanent pacemakers can result from placing defibrillator pads or paddles near the pacemaker
Defibrillation in the absence of an ECG rhythm (ie, 'blind defibrillation') to be avoided
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68. A shock can be accidentally delivered to other rescuers
Cont…
A shock can be accidentally delivered to other rescuers
The initial three shocks should be delivered in sequence, without interruption for CPR, medication administration, or pulse checks.
If transthoracic impedance is high, a low energy shock (< 100 J) may fail to generate enough current to achieve successful defibrillation.
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69. Never discharge the Defibrillator in Air to check its performance
Cont…
Alcohol should never be used as conducting material for paddles because serious burns can result.
Never discharge the Defibrillator in Air to check its performance
Never discharge with paddles shorted
Always clean the paddles after use
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70. Maintenance - Cleaning
For Exterior surface of defibrillator and battery /battery well or compartment
Isopropyl alcohol(70% in water)
Mild soap and water
Chlorine bleach (3% in water)
While cleaning take care that solution should not go inside the defibrillator. Use soft cloth for cleaning display, to prevent scratching.
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71. Maintenance - Cleaning
For Paddles, pads, Electrodes & cables
Disposable pads & monitoring Electrodes do not require cleaning. The paddles, paddle cable and patient cable, may cleaned with
Alcohol free hand soap
Chlorine bleach solution 10%in water
Isopropyl Alcohol
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72. Maintenance - Cleaning
Internal Paddles / Cables
Internal Paddle Handle/ Cable / Electrodes can be cleaned ultrasonically, autoclave or steam sterilized but follow the manufacturer's instruction for sterilization procedure
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73. PRECAUTIONS The paddles used in the procedure should not be placed:-
on a woman's breasts
over an internal pacemaker patients.
Before the paddle is used, a gel must be applied
to the patient's skin
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74. RISKS IN DEFIBRILLATION
Skin burns from the defibrillator paddles are the most common complication of defibrillation.
Other risks include injury to the heart muscle,
abnormal heart rhythms, and blood clots.
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75. TROUBLESHOOTING
Attach the external and internal paddles if the monitor reads, "No paddles."
Check to ensure that the leads are securely attached if the monitor reads, "No leads.“
Connect the unit to AC power if the message reads, "Low battery."
Verify that the Energy Select control settings are correct if the defibrillator does not charge.
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76. TROUBLESHOOTING
Change the electrodes and make sure that the electrodes adapter cable is properly connected if you receive a message of "PACER FAILURE." Restart the pacer.
Close the recorder door and the paper roll if the monitor message reads, "Check recorder”.
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77. PPM (Planned Preventive Maintenance)
Qualitative Task
PPM Task
Quantitative Task
Electrical Safety Test
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78. Test tool: Defibrillator Analyzer
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79. Defibrillator Analyzer
Basic Functions
Measures output energy
Measures cardioversion delay time
Measures output of pacemakers
Simulates range of ECG waveforms
Provides clinical training
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80. Practical Training and Assessment
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81. Questions!!!
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82. THANK YOU
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