A semi-automatic external defibrillator (AED)

A defibrillator is a medical device used in the defibrillation of the heart. It consists of a central unit and a set of two electrodes. The central unit provides a source of power and control. The two electrodes are placed directly on or in the patient. The device is designed to deliver an electric shock to the patient, in an effort to stop ventricular fibrillation or pulseless ventricular tachycardia. It is also used to stop the heart in an effort to allow it to reset its natural pacemaker in supraventricular tachycardia. Ventricular fibrillation is a situation of electrical chaos in the heart's conduction system, in essence distorting the coordinated contraction of cardiac muscular tissue. This leads to a situation where the heart produces minimal or no forward blood flow, causing circulatory arrest and death within minutes from hypoxic brain damage. The defibrillation current depolarizes the entire electrical system of the heart causing a complete cessation of electrical activity. This, in turn, gives the opportunity of impulses from the normal conduction pathways to regain control of the muscular tissue of the heart. Download high resolution version (2560x1920, 798 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (2560x1920, 798 KB) Wikipedia does not have an article with this exact name. ... A semi-automatic external defibrillator An automated external defibrillator (AED) is a portable electronic device that diagnoses and treats cardiac arrest by re-establishing an effective heart rhythm. ... Typical view of the defibrillator operator. ... Ventricular fibrillation (V-fib or VF) is a cardiac condition which consists of a lack of coordination of the contraction of the muscle tissue of the large chambers of the heart that eventually leads to the heart stopping altogether. ... A supraventricular tachycardia (SVT) is a rapid rhythm of the heart in which the origin of the electrical signal is either the atria or the AV node. ...

Types of Defibrillators

Internal Defibrillators

The device may be implanted directly in the user of the device. If so, it is known as an implantable cardioverter-defibrillator (ICD). This type of defibrillator is designed to provide immediate defibrillation to high-risk patients. By actively monitoring the pulse rate, rhythm, and waveform, and by comparing atrial and ventricular activity, an ICD can detect ventricular fibrillation, and immediately initiate defibrillation^[1][2]. An implantable cardioverter-defibrillator (ICD), also known as an automated implantable cardioverter-defibrillator (AICD), is a device that is implanted under the skin of patients that are at risk of sudden cardiac death due to ventricular fibrillation. ...

External Defibrillators

External defibrillator / monitor

External defibrillators are typically used in hospitals or ambulances, but are increasingly common outside the medical realm, as automated external defibrillators become safer and cheaper. There are a variety of technologies and form factors in use for external defibrillators, and recent progress in cardiac research has led to substantial improvements in the underlying technology. Image File history File linksMetadata Download high resolution version (1600x1200, 702 KB) Beschreibung Description: A defibrillator/monitor/pacer from an ambulance in Graz, Austria. ... Image File history File linksMetadata Download high resolution version (1600x1200, 702 KB) Beschreibung Description: A defibrillator/monitor/pacer from an ambulance in Graz, Austria. ...

Biphasic Defibrillation

Until recently, external defibrillators relied on monophasic shock waves. Electrical pulses are sent rapidly from one electrode to the other, only in one direction. Biphasic defibrillation, however, alternates the direction of the pulses, completing one cycle in approximately 10 milliseconds. Biphasic defibrillation was originally developed and used for implantable cardioverter-defibrillators. When applied to external defibrillators, biphasic defibrillation significantly decreases the energy level necessary for successful defibrillation. This, in turn, decreases risk of burns and myocardial damage.
Ventricular fibrillation (VF) could persist in about 40% of cardiac arrest patients treated with a single shock from a monophasic defibrillator. Most biphasic defibrillators have a first shock success rate (VF is eliminated and a normal rhythm can be returned) of greater than 90%.^[3]

Automated External Defibrillators

A public access automated external defibrillator in Monaco. These can be used by bystanders.

An Automated External Defibrillator (AED) is a self-contained defibrillator device designed for portability and ease of use. AEDs are generally shaped like a briefcase, so that they may be carried easily by a handle. An AED contains a battery, a control computer, and electrodes. Upon placing the electrodes on the patient, the control computer in an advanced system will assess the patient, determining the type of rhythm or arrhythmia present. It will then set appropriate power levels and signal that a shock is needed. If the patient does not require defibrillation, units will not allow a shock to be administered. A button must still be depressed manually to trigger the shock, as the operator beforehand must be certain that no-one is touching the patient at that time. Often, AEDs will have speakers which give audible commands when the AED is opened. Image File history File linksMetadata Download high resolution version (2048x1536, 1543 KB) Summary Licensing File links The following pages link to this file: Defibrillator Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ... Image File history File linksMetadata Download high resolution version (2048x1536, 1543 KB) Summary Licensing File links The following pages link to this file: Defibrillator Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ... A semi-automatic external defibrillator An automated external defibrillator (AED) is a portable electronic device that diagnoses and treats cardiac arrest by re-establishing an effective heart rhythm. ...

Current AED devices are designed for emergency medical technicians, home users, public safety officers and other people with minimal medical knowledge. AEDs are available for $1000 for a basic model to several thousand dollars for a more fully-featured or durable model.

Electrodes

The electrode is a key part of any defibrillation system. The proper selection and placement of electrodes can determine the effectiveness of the procedure.

Design

The most well-known type of electrode is the traditional metal paddle with an insulated handle. This type must be held in place on the patient's skin while a shock or a series of shocks is delivered. Before the paddle is used, a gel must be applied to the patient's skin, in order to ensure a good connection and to minimize electrical resistance, also called chest impedance (despite the DC discharge). Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ...

A circuit diagram showing the simplest (non-electronically controlled) defibrillator design, depending on the inductor ( damping ), producing a Lown, Edmark or Gurvich Waveform

Another type of resuscitation electrode is designed as an adhesive pad. When a patient has been admitted due to heart problems, and the physician or nurse has determined that he or she is at risk of arrhythmia, they may apply adhesive electrodes to the patient in anticipation of any problems that may arise. These electrodes are left connected to a defibrillator. If defibrillation is required, the machine is charged, and the shock is delivered, without any need to apply any gel or to retrieve and place any paddles. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... A cardiac arrhythmia, also called cardiac dysrhythmia, is a disturbance in the regular rhythm of the heartbeat. ...

Both solid- and wet-gel adhesive electrodes are available. Solid-gel electrodes are more convenient, because there is no need to clean the patient's skin after removing the electrodes. However, the use of solid-gel electrodes presents a higher risk of burns during defibrillation, since wet-gel electrodes more evenly conduct electricity into the body.

Adhesive electrodes are designed to be used not only for defibrillation, but also for non-invasive pacing and electrical cardioversion. Through electricity or drug therapy, cardioversion converts heart arrhythmias to normal rhythms. ...

While the paddles on a Monitor/Defibrillator may be quicker than using the patches, adhesive patches are superior due to their ability to provide appropriate EKG tracing without the artifact visible from human interference with the paddles. Many monitor defibrillators provide three, five or 12-lead EKG monitoring to compensate for this downfall of the paddles. Adhesive electrodes are also inherently safer than the paddles for the operator of the defibrillator to use, as they minimize the risk of the operator coming into physical (and thus electrical) contact with the patient as the shock is delivered, by allowing the operator to stand several feet away. Another inconvenience of the paddles is the requirement of around 25lbs of pressure to be applied while defibrillating. ECG may also refer to the East Coast Greenway Lead II An Electrocardiogram (ECG or EKG, abbreviated from the German Elektrokardiogramm) is a graphic produced by an electrocardiograph, which records the electrical voltage in the heart in the form of a continuous strip graph. ... In natural science and signal processing, an artifact is any perceived distortion or other data error caused by the instrument of observation. ...

Placement

Anterio-apical placement of external defibrillator electrodes (When defibrillation is unsuccessful, anterio-posterior placement is also sometimes attempted)

Resuscitation electrodes are placed according to one of two schemes. The anterior-posterior scheme (conf. image) is the preferred scheme for long-term electrode placement. One electrode is placed over the left precordium (the lower part of the chest, in front of the heart). The other electrode is placed on the back, behind the heart in the region between the scapula. This placement is preferred because it is best for non-invasive pacing. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ...

The anterior-apex scheme can be used when the anterior-posterior scheme is inconvenient or unnecessary. In this scheme, the anterior electrode is placed on the right, below the clavicle. The apex electrode is applied to the left side of the patient, just below and to the left of the pectoral muscle. This scheme works well for defibrillation and cardioversion, as well as for monitoring an ECG.

Inventor

The first case of a human life saved by defibrillation was reported by Beck et al in 1947. Dr. Claude Beck successfully revived a patient in an operating room using an open-chest electric defibrillation device, which had been designed by him and then built by his friend James Rand. Dr. Claude Schaeffer Beck (1894-1971) was a pioneer American cardiac surgeon, famous for innovating various cardiac surgery techniques, and performing the first defibrillation in 1947. ...

The first man to discover that DC electricity is most effective for treating arrhythmias like ventricular fibrillation and ventricular tachycardia is Bernard Lown. AC electricity cannot be used because it is considerably more likely to induce ventricular fibrillation rather than terminating it. Direct current (DC or continuous current) is the continuous flow of electricity through a conductor such as a wire from high to low potential. ... Ventricular fibrillation (V-fib or VF) is a cardiac condition which consists of a lack of coordination of the contraction of the muscle tissue of the large chambers of the heart that eventually leads to the heart stopping altogether. ... Ventricular tachycardia (V-tach or VT) is a fast rhythm that originates in one of the ventricles of the heart. ... Bernard Lown, M.D. was the original developer of the defibrillator and is an internationally known peace activist. ... City lights viewed in a motion blurred exposure. ... Ventricular fibrillation (V-fib or VF) is a cardiac condition which consists of a lack of coordination of the contraction of the muscle tissue of the large chambers of the heart that eventually leads to the heart stopping altogether. ...

The closed-chest defibrillator device was pioneered by Dr V. Eskin with assistance by A. Klimov in the city of Frunze, USSR in mid 1950s. Successors of this device continue to be used to this day.

External defibrillators were developed for NASA to be used in their human centrifuge at Moffat Field in Mountain View, California,, by Tom Corbin in 1956. These external units were also used by W.B.Kouwenhoven at Johns Hopkins University in his development of the technique now known as CPR. For other meanings of CPR, see CPR (disambiguation). ...

Another advance was the development of a mobile defibrillator in 1966. The device was suitable for installation in ambulance vehicles and was developed by cardiologist Frank Pantridge in Belfast, Northern Ireland. This is one of the innovations that led to modern EMS and, in the late 1990s, the mobilization of advanced cardiac life support with paramedics. An ambulance in San Jose Del Cabo, Mexico A Helicopter used as an Ambulance. ... James Francis Frank Pantridge (October 3, 1916, Hillsborough – 26 December 2004) was a Northern Ireland physician and cardiologist who transformed emergency medicine and paramedic services with the invention of the portable defibrillator. ... WGS-84 (GPS) Coordinates: 54. ... Anthem: UK: God Save the Queen Regional: (de facto) Londonderry Air Capital Belfast Largest city Belfast Official languages English (de facto), Irish, Ulster Scots 3, BSL, NISL, ISL Government Constitutional monarchy  - Queen Queen Elizabeth II  - Prime Minister of the UK Tony Blair MP  - First Minister Ian Paisley  - Deputy First Minister... The examples and perspective in this article or section may not represent a worldwide view. ... Advanced cardiac life support or (ACLS) refers to a set of clinical interventions for the urgent treatment of cardiac arrest and other life threatening medical emergencies, as well as the knowledge and skills to deploy those interventions. ...

Defibrillators in popular culture

The defibrillator was first seen on film in the 1966 movie Fantastic Voyage. Since then they have appeared in many modern television and film medical programs. Its use in the near-death experience experiments by the characters of the 1990 movie Flatliners made the defibrillator virtually one of the co-stars of that film. It was also utilized in plotlines in several films and TV series. 1966 (MCMLXVI) was a common year starting on Saturday (the link is to a full 1966 calendar). ... Fantastic Voyage is a 1966 science fiction film written by Harry Kleiner. ... MCMXC redirects here; for the Enigma album, see MCMXC a. ... Flatliners is a 1990 film starring Kiefer Sutherland, Julia Roberts, Kevin Bacon, William Baldwin and Oliver Platt as medical students experimenting with near-death experiences. ...

In the television series Emergency!, firefighters John Gage and Roy DeSoto often used defibrillators, starting the film tradition of yelling "Clear" right before applying the shock, to warn everyone around to stay away from the patient for risk of electrical shock.

In the same series, the defibrillator induces a sudden, violent jerk or convulsion by the patient; in reality, although the muscles may contract, such dramatic patient presentation is rare.

Most television shows will have the medical provider defibrillate the "flat-line" ECG rhythm (also known as asystole); this is not done in real life. Only the cardiac arrest rhythms ventricular fibrillation and pulseless ventricular tachycardia are normally defibrillated. (There are also several heart rhythms that can be "defibrillated" when the patient is not in cardiac arrest, such as supraventricular tachycardia or ventricular tachycardia that produces a pulse, though the procedure is then known as cardioversion.) However, a flatline may actually be a fibrillation that is too weak to be seen on the monitor (fine v-fib), so a shock may be delivered, but it is not regarded as the treatment of choice, as the probability of a successful conversion is very small. According to the current guidelines, in this situation, continued CPR in order to improve the oxygenation of the heart for a few minutes is preferred before defibrillation is attempted. In medicine, asystole is a state of no cardiac electrical activity, hence no contractions of the myocardium and no cardiac output or blood flow. ... Ventricular fibrillation (V-fib or VF) is a cardiac condition which consists of a lack of coordination of the contraction of the muscle tissue of the large chambers of the heart that eventually leads to the heart stopping altogether. ... Ventricular tachycardia (V-tach or VT) is a fast rhythm that originates in one of the ventricles of the heart. ... A supraventricular tachycardia (SVT) is a rapid rhythm of the heart in which the origin of the electrical signal is either the atria or the AV node. ... For other uses, see Pulse (disambiguation). ... Through electricity or drug therapy, cardioversion converts heart arrhythmias to normal rhythms. ...

During the penultimate season of M*A*S*H, in the episode "Heroes", B. J. Hunnicutt saves a patient's life by using a hastily-assembled defibrillator after reading an article in a medical journal (contrary to history, Hawkeye Pierce suggests that the technique had previously only been tested on dogs). His colleague claims he's just invented a new way of saving lives. Season 10: 1981-1982 ... M*A*S*H was an American television series developed by Larry Gelbart and inspired by the 1961 novel Catch-22, the 1968 Richard Hooker novel M*A*S*H: A Novel About Three Army Doctors and its sequels; and—primarily—the 1970 film MASH. It is the most well... Captain B.J. Hunnicutt (played by Mike Farrell) is a fictional character in the TV show M*A*S*H, which ran from 1972-1983 on CBS. Captain Hunnicutt resided in Mill Valley, California before he was recruited to join the US Army to fight in the War. ... Captain Benjamin Franklin “Hawkeye” Pierce is the lead fictional character in the M*A*S*H novels, film, and television series. ... Trinomial name Canis lupus familiaris The dog (Canis lupus familiaris) is a domestic subspecies of the wolf, a mammal of the Canidae family of the order Carnivora. ...

In the 1988 film Short Circuit 2, Benjamin used a defibrillator to provide the robot Johnny 5 with temporary power when its leaking battery ran out of power. It also played a chief role in a scene in the 1989 film The Abyss, when Lindsey Brigman allowed herself to be drowned in freezing water so she and her husband, Bud, could both make it back to the Deep Core underwater drilling station. // Michael Jacksons first film was Moonwalker Rain Man, starring Dustin Hoffman and Tom Cruise Who Framed Roger Rabbit, starring Bob Hoskins Coming to America, starring Eddie Murphy Big, starring Tom Hanks Twins, starring Arnold Schwarzenegger and Danny DeVito Crocodile Dundee II Die Hard, starring Bruce Willis The Naked Gun... Short Circuit 2 is a 1988 motion picture, sequel to Short Circuit. ... Johnny 5 explores the city. ... // Actress Kim Basinger and her brother Mick purchase Braselton, Georgia for $20 million. ... The Abyss is an award-winning science fiction film from 1989, written and directed by James Cameron, starring Ed Harris, Mary Elizabeth Mastrantonio, and Michael Biehn. ...

In the computer games Battlefield 2 and Battlefield 2142, the defibrillator is a tool available for medics. Contrary to reality, they are surprisingly convenient and mobile tools that can quickly revive a fallen comrade, or kill an enemy soldier with a single jolt. Battlefield 2 (abbreviated to BF2) is a computer game where players fight in a modern (early Twenty-First Century) battlefield using state-of-the-art firearms and vehicles. ... Battlefield 2142 is a computer game designed by Digital Illusions CE and is the fourth game in the Battlefield series. ... A combat medic is a trained soldier who is responsible for providing first aid and frontline trauma care on the battlefield. ...

In the 1998 Farelly brothers classic "There's Something about Mary" there is a hilarious AED use segment. Matt Dillon's character Pat Healey has drugged a little dog to control it's agressiveness towards him. However he goes too far and the dog dies, and he has to go into quick action to save the dog. He does a rendition of CPR, and then pulls electrical cord from a nearby lamp and "defibrillates" the dog with them.

In the 2006 James Bond movie Casino Royale, Bond uses a defibrillator from his Aston Martin DBS, to revive himself after being poisoned with digitalis during his poker game. On returning to the table he wittily remarks "Sorry; that last hand -- nearly killed me." Flemings commissioned image of James Bond to aid the Daily Express comic strip artists. ... Casino Royale is the 21st film in the James Bond series and the first to star Daniel Craig as MI6 agent James Bond. ... The Aston Martin DBS is a GT car produced by the English manufacturer Aston Martin Lagonda Ltd. ... Species About 20 species, including: Digitalis cariensis Digitalis ciliata Digitalis davisiana Digitalis dubia Digitalis ferruginea Digitalis grandiflora Digitalis laevigata Digitalis lanata Digitalis leucophaea Digitalis lutea Digitalis obscura Digitalis parviflora Digitalis purpurea Digitalis thapsi Digitalis trojana Digitalis viridiflora Digitalis is a genus of about 20 species of herbaceous biennials, perennials and... A game of Texas holdem, the most popular form of poker, in progress. ...

See also

• cardiopulmonary resuscitation (CPR)
• Advanced cardiac life support (ACLS)
• Cardioversion
• Implantable cardioverter-defibrillator
• Defibrillation
• Automated external defibrillator
• Heart Attack
• Packer Whacker

In the 1998 Farelly brothers classic "There's Something about Mary" there is a hilarious AED use segment. Matt Dillon's character Pat Healey has drugged a little dog to control it's agressiveness towards him. However he goes too far and the dog dies, and he has to go into quick action to save the dog. He does a rendition of CPR, and then pulls electrical cord from a nearby lamp and "defibrillates" the dog with them. Wikibooks has more about this subject: First Aid/CPR Cardiopulmonary resuscitation (CPR) is an emergency first aid procedure for a victim of cardiac arrest. ... Advanced cardiac life support or (ACLS) refers to a set of clinical interventions for the urgent treatment of cardiac arrest and other life threatening medical emergencies, as well as the knowledge and skills to deploy those interventions. ... Through electricity or drug therapy, cardioversion converts heart arrhythmias to normal rhythms. ... An implantable cardioverter-defibrillator (ICD), also known as an automated implantable cardioverter-defibrillator (AICD), is a device that is implanted under the skin of patients that are at risk of sudden cardiac death due to ventricular fibrillation. ... Typical view of the defibrillator operator. ... A semi-automatic external defibrillator An automated external defibrillator (AED) is a portable electronic device that diagnoses and treats cardiac arrest by re-establishing an effective heart rhythm. ... A myocardial infarction occurs when an atherosclerotic plaque slowly builds up in the inner lining of a coronary artery and then suddenly ruptures, totally occluding the artery and preventing blood flow downstream. ... It has been suggested that this article or section be merged into Defibrillator. ...

References

Advanced Cardiac Life Support- American Heart Association

External links

Wikimedia Commons has media related to:

Defibrillator

• How an internal defibrillator is implanted from Children's Hospital Heart Center, Seattle.