Design Anaysis of Defibrillator and Implementing Wireless Charging System

This work is aimed to evaluate the design of the defibrillator and to determine the difficulties to incorporate a wireless charging system in external defibrillator. Defibrillators are the life saving equipment used for a patient having sudden cardiac arrest. The main component in a defibrillator is the high voltage capacitor which should get charged quickly. In a classical monophasic defibrillator, energy range is of 150 to 400Joules and in biphasic defibrillator 150 to 360Joules energy is produced for time duration of 8 to 10msec. Such a huge energy in a small period of time will produce a high output voltage in the range of 200 to 1000V. In case of internal defibrillator, the energy up to 40J is released to the cardiac muscles directly. The capacitor of an external defibrillator should be charged fully in order to discharge required energy to the patient's heart and the charging time should be small enough to provide maximum of three consecutive shocks in failure of first and second attempt. Nowadays, the wireless charging system is most common in every area, but not much among medical devices. In case of external defibrillator, when designing a wireless charging system, the device size will get reduced into the size of defibrillator paddle. In this work, when designed an external defibrillator for discharging 150J in duration of 10msec, the capacitance value obtained is 0.03F and the discharge voltage of 866V. There is no such capacitor with this much voltage rating of smaller size is available today. So it is designed to implement wireless charging in a defibrillator and developed such a circuit model in printed circuit board (PCB) at the end. The output energy produced by the prototype of wireless charging defibrillator is 45J.