Heart defibrillator works

Heart defibrillator, also known as electrical cardioversion machine, it is a shock to the rescue and treatment of cardiac arrhythmias of medical electronic devices.

Therapeutic effect of high, fast, easy and more secure than with drugs, etc., are widely used in medical units units at various levels. Defibrillator works with strong pulse through the heart to arrhythmias, so back to sinus rhythm method, called electric defibrillation or cardioverter. Pacemaker and defibrillator are exogenous to the current treatment of cardiac arrhythmias, both for modern methods of treating arrhythmia. Cardiac pacing and cardiac defibrillator cardioversion difference is: the latter electric shock when the heart cardioversion is an instantaneous high energy pulses, General duration is 4 ~ 10ms, power at 40-400J (joules). Electric shock for cardiac defibrillator equipment called a defibrillator, it can complete electric cardioversion, i.e. defibrillation. When patients experienced a severe arrhythmia, atrial flutter or atrial fibrillation, supraventricular or ventricular tachycardia, often resulting in different levels of blood motility disorder. Especially when it occurs in patients with ventricular fibrillation, ventricular contractility without overall, heart ejection and blood circulation, if not timely rescue, often resulting in a long time due to asphyxia. As a defibrillator, the control must have the energy of electric current through the heart, can eliminate certain cardiac rhythm disorders, cardiac rhythm back to normal, so that the heart disease patients receive rescue and treatment. The original defibrillator is using industrial AC direct defibrillator, the defibrillator regular electric shock and injury because, as a result, the current exception during cardiac surgery is carried out using the AC in vivo defibrillation (ventricular fibrillation), generally used DC defibrillation. General cardiac defibrillator majority adopts RLC damping discharge method, its charge and discharge principle as in Figure 6-1-1.

Voltage converter is a DC voltage into pulse pressure, high voltage rectifier Capacitance to energy storage, so that the capacitance C charge for certain energy storage.

Defibrillator therapy, control of high-voltage relays K action so that the charging circuit is cut off by the capacitor energy storage C, inductance L and the human body (load) in series connected to form the RLC (R-body resistance, conductor resistance, the human body itself and electrode contact resistance III) series resonance damping oscillation circuit, a damping oscillation discharge circuit, through the heart of current waveform as in Figure 6-1-2. Clinical laboratory and are proved that this two-way RLC discharge peak current defibrillation works well, and on human tissue damage. As mentioned earlier, the discharge time typically 4 ~ 10ms, can properly select L, C implementation. Inductance L open core coil should be adopted to prevent the discharge caused by large current core saturation caused inductance values declining, while the output waveform changes. In addition, defibrillation in high voltage, the operator and patient had the accident risk of electric shock, it is necessary to prevent erroneous actions and take various protection circuits. Heart defibrillator addition should have the charging circuit and discharge circuit, you should have a monitoring device for a timely check defibrillation and defibrillation. Monitoring unit has two kinds: one is the ECG oscilloscope, oscilloscope screen on the observation of defibrillator output waveform to be monitored; the other is the same as ECG Recorder, the defibrillator output waveform and electrocardiogram automatic description written in the history of paper, reach monitoring purposes. Of course, some also have these two devices, you can observe the waveform on the screen, and you can put the waveform automatically down stroke. Have a first aid unit consists of cardiac pacemaker, cardiac defibrillator and monitors, automatic recorder with combination, is the heart of good first aid instruments. Defibrillator (1) in accordance with the R-sync to 1, non-synchronization-defibrillator. The defibrillator in defibrillation with patients own R wave are not synchronized, available in ventricular fibrillation and flutter (because at this point no vibration amplitude is high enough, the slope of the R wave large enough). 2, sync-defibrillator. The defibrillator in defibrillation with patients own R wave in sync. General is the use of electronic control circuit, the R wave control current pulse of the electric shock pulse happens to fall on the R wave in decline, this makes a shock pulse does not fall on irritable period, thereby avoiding ventricular fibrillation. Can be used in addition to ventricular fibrillation and flutter all tachyarrhythmia, such as supraventricular and ventricular tachycardia, atrial fibrillation and flutter, etc. (2) press the electrode plate positioned to 1, in vivo defibrillator. The defibrillator electrodes placed on the chest in direct contact with the heart for defibrillation. Early defibrillation is mainly used for Thoracic cardiac surgery, cardiac shock when direct such intimate defibrillator simple structure. Modern internal defibrillator was implanted, and early in vivo defibrillator is quite different from that in addition to automatic defibrillator, you can automate the ECG monitoring, arrhythmia judgement, therapy options. 2. External Defibrillator. The defibrillator electrodes placed on the chest, indirect contact cardiac defibrillator. Current clinical use of defibrillators are mostly belong to this type.