1. Defibrillators
WHO. “Defibrillator, External, Automated; Semiautomated.” From the publication: Core Medical Equipment. Geneva, Switzerland, 2011.

2. Summary Quiz Commercial Examples Clinical Use Preventive Maintenance
History
Specifications
Principles of Operation
Block Diagram
Commercial Examples
Preventive Maintenance
Common Problems
Test Procedures

3. Quiz
What is the 2 main clinical cases that require the use of defibrillator?
What are the different types of defibrillator?
What is the defibrillator waveform polarity?
Does one need to use gel? Why?

4. Quiz What kind of paddles can be used?
Draw the 2 possible of paddles placement in the case of external electrodes.
Can one use a defibrillator with a patient on a OR table? Why?
What are 2 ways to test a defibrillator
What is the most common problem in defibrillators from the developing world?

5. Fibrillation
Cardiac arrest occurs in more than 500,000 people annually in the United States
Atrial fibrillation (AF) is relatively common and can be well tolerated by the patient

6. Fibrillation
Jer5150 (2012) Fibrillation [Image], retrieved from

7. Ventricular Fibrillation
Ventricular fibrillation (VF) causes the heart to stop pumping blood immediately
Irreversible brain damage or death after 5 minutes
Most common cause of death

8. Clinical Use Reverse fibrillation of the heart (300 J to 360 J)
Restoring the heart’s normally coordinated contractions (below 200 J) – Requires ECG
[Drawing of defibrillator pads placement] retrieved from

9. History
1899
Physiologists Prevost and Batelli from University of Geneva used small electric shocks to induce ventricular fibrillation in dogs, and larger charges to reverse the condition
Beck's theory was that ventricular fibrillation often occurred in hearts which were fundamentally healthy, in his terms "Heart too good to die", and that there must be a way of saving them. Beck first used the technique successfully on a 14 year old boy who was being operated on for a congenital chest defect. The boy's chest was surgically opened, and manual cardiac massage was undertaken for 45 minutes until the arrival of the defibrillator. Beck used internal paddles on either side of the heart, along with procainamide, a heart drug, and achieved return of normal sinus rhythm.
Until the early 1950s, defibrillation of the heart was possible only when the chest cavity was open during surgery. The technique used an alternating current from a 300 or greater volt source delivered to the sides of the exposed heart by 'paddle' electrodes where each electrode was a flat or slightly concave metal plate of about 40 mm diameter. The closed-chest defibrillator device which applied an alternating current of greater than 1000 volts, conducted by means of externally applied electrodes through the chest cage to the heart, was pioneered by Dr V. Eskin with assistance by A. Klimov in Frunze, USSR in mid 1950s.

10. History
1947
First use on a human by Claude Beck, professor of surgery at Case Western Reserve University

11. Specifications Input Electrical: ECG signal Output
Electrical: 3000 V pulse during 10 ms
Electronically (display)
PhilippN, (November 2007), Position of Electrodes during Defibrillation, retrieved from

12. Principles of Operation
Electric current is placed through electrodes:
Directly on the heart - low current – 300 V AC.
Transthoracically – large area electrodes, higher current – V AC
Energy Discharge: 0 to 360 watt/ seconds (Joules)… around 50 mA
[Photograph of defribrilator] retrieved from

13. Types of Defibrillators
Manual defibrillator (most common in developing world)
Automated external defibrillators
AED (Home defibrillator)
Implantable defibrillator
WHO. “Defibrillator, External, Automated; Semiautomated.” From the publication: Core Medical Equipment. Geneva, Switzerland, 2011.
Steven Rodriquez (2007), Defibrillator [photograph], retrieved from

14. Output Pulses Edmark Waveform Maximum Pulse 7,500 V
Common in the poor world
Severe damage (death)
Be clear of the patient during the discharge vp
2kv
~10 ms
Virginia Reid (2015), Waveform [drawing]

15. Output Pulses Biphasic truncated exponential
Virginia Reid (2015), Output Pulses, [drawing]
Biphasic truncated exponential
Monophasic truncated exponential
Safest Waveform

16. Manual Defibrillators ECG
ECG leads can also be connected from the device to the patient
However, most can monitor the ECG through the defibrillation paddles as well.
Aededitor (2011), Semi-automated external monitor defibrillator [photograph], retrieved from

17. Synchronization Shock point
Husche (2015), ECG Figure EN [diagram]. Adapted from

18. ECG Synchronization Relevance???
Anthony Atkielski (2012), Sinus Rhythm Labels [diagram]. Retrieved from

19. Paddles Excellent contact with the body is essential
Gel required
Serious burns can occur if proper contact is not maintained during discharge
Sufficient insulation is required
Prevents discharge into the physician

20. Paddles Types Internal: direct cardiac stimulation
External: transthoracic stimulation
Adult
Pediatric
Disposable: used externally

21. Paddles Types Disposable Internal External
Yury Masloboev (2007), Defibrillator, [photograph]. Retrieved from

22. Paddles Position
DHTLab (2015), Defibrilator Packet, retrieved from BMET Library

23. Paddles Position
Owain Davies (2012), Defib electrode placement, retrieved from

24. Schematics
Openstax College. “Cardiac Muscle and Electrical Activity.” From the publication: Biology. Rice University: 2013.

25. Internal (Implantable) Defibrillator
BruceBlaus (2013), Implantable Cardioverter Defibrilator [diagram]. Retrieved from

26. Commercial Examples External Defibrillator
Openstax College. “Cardiac Muscle and Electrical Activity.” From the publication: Biology. Rice University: 2013.

27. Commercial Examples Internal Defibrillator
Steven Rodriquez (2007), Defibrillator [photograph], retrieved from
Gregory Marcus (2008) Implantable cardioverter defibrillator chest X-ray [photograph] retrieved from

28. Commercial Examples AED
Wikipedia. “Automated External Defibrillator.” Wikipedia, p Retrieved from:

29. Safety Avoid conducting mattress (spring), bedstead or metal table
Wear surgeon’s rubber gloves with high-voltage insulation
CAUTION: high current and voltage associated with the circuitry.
Use GEL
A completely different approach to measuring blood pressure is to invasively introduce a catheter
into an artery. This is most common in surgery and intensive care units. The blood pressure
device is connected to the catheter via a rigid wall plastic tube filled with a saline solution. The
tube is connected to a transducer, which may be connected to bag of saline or “flush.” Figure
2.7.3 illustrates the set up. The transducer is hung at the level of the heart. The output from
the transducer is amplified and displayed as numbers, waveform or both. Since the skin has
been breached the patients first line of defense for both infection and electrical shock have been
bypassed. Extreme care must be taken to assure the safety of the
patient.
Werneuchen (2008) Surgical Gloves [photograph]. Retrieved from

30. Preventive Maintenance
Replaced battery every 24 months
Defibrillators offer a selftest option which should be done at least once a month

31. Common Problems Old Batteries Paddles and cables contact
The gel build up on the paddles and have to be cleaned with alcohol

32. Test Procedures Paddles should be inspected for pit marks
They could leave burns on the chest

33. NEVER TEST THE PADDLES AGAINST EACH OTHER!
Test Procedures
Defribillator Selftest
Use a fresh meat (normally pig)
NEVER TEST THE PADDLES AGAINST EACH OTHER!

34. Questions ?

35. Troubleshooting