There are many kinds of defibrillators, and the principle of AED is briefly described:
Working Principle: AED was developed as early as 1979, and in 1994, the American AHA/ACC formulated the relevant recommendations, which initiated the comprehensive application of the AED system. 90's has not been developed into a fully automated external defibrillator (F-AED).AED's basic working The principle uses the modulation zone equation (MDF) to identify ventricular and supraventricular arrhythmias, with automatic identification, analysis of cardiac rhythms, automatic charging and discharging, and self-test functions. It uses 2 disposable defibrillation telegraph pads connected to 4 guardian electrodes, and simultaneously displays the ECG of 3 guardian leads in real time. It can deliver 8 shocks in one tachycardia, each discharge energy and delay time can be programmed, defibrillation current intensity between 5-360J, and shock interval time can be programmed between 10-600 seconds. The new generation of AEDs tends to use biphasic wave currents (120J-200J) with low energy consumption, low damage and high repetitive rhythms, which are much lower than monophasic waves with 200-360J energy, but their defibrillation efficiency (98%) is significantly higher than the latter (67%). And compared with conventional defibrillation, AED improves survival by a factor of 1.8. Randomized controlled studies have shown that both trained healthcare professionals and lay people, as well as lay witnesses and family members, can effectively use AEDs to resuscitate cardiac arrest victims, with trainees administering shocks in an average of 25 seconds, and sixth-grade schoolchildren in an average of 90 seconds. It provides continuous monitoring, rapid recognition and rapid response, is safe and reliable, and has the potential to effectively reduce the incidence of cardiac arrest and mortality.
Physiological basis of defibrillators
A defibrillator is a medical electronic device that applies electric shocks to resuscitate and treat cardiac arrhythmias. The heart can only produce an effective beat when all of the heart's muscle fibers are contracting in precise synchronization. When a patient experiences a severe tachyarrhythmia, such as atrial flutter, atrial fibrillation, supraventricular or ventricular tachycardia, it often results in varying degrees of hemodynamic impairment. Especially when patients develop ventricular fibrillation, normal and regular ventricular contractions are replaced by rapid and irregular fibrillation, causing a severe sharp reduction in blood output. If the normal heart rhythm is not restored quickly, the patient will soon die.
In ectopic tachyarrhythmias, some of the myocardial electrical activity is not in phase due to factors such as increased autoregulation at the ectopic pacing site and the presence of triggering or refractory mechanisms. If in a short period of time through the chest wall or directly to the heart with high current, artificially make all myocardial fibers instantaneous and simultaneous depolarization, ectopic rhythm is also eliminated, at this time, such as cardiac pacing and conduction system in the sinus node of the highest autoregulation, can restore its cardiac pacing point and control the heart beat, that is, resumption of sinus rhythm, which is the defibrillator effect of the physiological mechanism.
Let all personnel get out of the way is to avoid others through the bed and other conductive subject to electrical damage! It also affects the patient's electrical conduction