Automatic external defibrillator (AED) and its working principle
1. Cardiac Arrest and Ventricular Fibrillation
Cardiac Arrest is also called "Sudden Cardiac Arrest" or "Unexpected Cardiac Arrest", which refers to the sudden stop of the effective contraction and pumping function of the heart. Sudden illness, trauma, poisoning, etc. are common causes of cardiac arrest.
After the occurrence of cardiac arrest, the blood supply to various organs in the body was completely interrupted within tens of seconds due to the cessation of blood circulation, which quickly put the patient in the stage of clinical death. The sudden death (also called sudden cardiac death) that we often hear occurs within a few minutes after the appearance of this symptom.
Ventricular fibrillation will occur in the heart of 90% of cardiac arrest patients. At this time, defibrillation with electric shock will usually receive good results. This electric shock device is an automatic external defibrillator called a "life-saving artifact".
2. Introduction to AED
In the implementation and operation of cardiopulmonary resuscitation, there is a very important equipment and a very important skill, that is, AED and its use.
The full name of AED in English is Automated External Defibrillator, which literally translates to "automatic, external, shock-carrying defibrillator", abbreviated as "automated external defibrillator", it is a non-professional level, for non-medical personnel The portable electrical defibrillation instrument used can diagnose specific arrhythmia and give electrical shock defibrillation. It is known as a life-saving artifact for patients with cardiac arrest.
Three, the working principle of AED
We know that the heart has its own electrical rhythm. When encountering severe electric shock, drowning or the middle and late stages of disease, this electrical rhythm will be disordered. This disorder generally has two conditions, one is "ventricular fibrillation", also called "ventricular flutter", and the other is "pulseless ventricular tachycardia", also called "pulseless ventricular tachycardia" In these two cases, although the myocardium has a certain movement, it is not actually "pumping" but "trembling". It loses its blood intake function and therefore cannot effectively send blood to the whole body. Cardiac defibrillator, including the automatic defibrillator we are talking about here, its role is to give the heart an electric shock to return its disordered rhythm to normal, that is, to eliminate the heart's "tremor" and restore its normal blood pumping Features.
Data show that for every minute of delay in defibrillation, the mortality rate will increase by 7% to 10%. Therefore, in emergency situations, especially outside the hospital, using AED as early as possible to externally defibrillate patients with cardiac arrest will play a vital role in saving their lives.
