Research On Core Technology Of External Defibrillator And Simulation Of Low Energy Defibrillation

SCD (Sudden Cardiac Death) is the leading course of patients with cardiovascular diseases, it leads millions of sudden deaths every year over the world, causing great loses to families and society. Therefore, the therapy of VF (Ventricular Fibrillation) which has very close relationship with SCD, has always being a research focus in cardiac electrophysiology. After long periods of medical researches and practices, electric shock treatment has been proved as the most effective way in terminating VF till now.ED (External Defibrillator) is a first aid device specially designed for patients with VF, it plays an important role in saving patients from SCD and improving survival rates. Therefore, it is of profound social significance and great economic value in developing ED with our own intellectual property rights.ED save patients through electric shock and the key factor in deciding success or failure is defibrillation energy. When the defibrillation energy is too high, it may not only cause unnecessary suffering and psychological burden to patients, but also damage the heart cells seriously and lead to heart failure. When the energy is too low, it may not be enough to meet the recovery threshold. Therefore, it is of great significance and necessity studying how to defibrillate with appropriate energy.There are two parts in this paper:the first part is about the design of external defibrillator and the second part is about low-energy defibrillation simulation based on SCIRun platform.The designed defibrillator can be divided into two units, the high voltage unit and the low voltage unit. The high voltage unit is controlled by a MCU and includes the following parts:fast charging circuit, voltage detection circuit, dual phase discharge bridge and self-discharge circuit. The low voltage unit is responsible for the implementation of signal conditioning, data acquisition, logic control and other auxiliary functions and also controlled by a MCU. It includes the following parts: ECG conditioning circuit, thoracic impedance measurement circuit, data storage module, state indication module and embedded control module. The high voltage unit and the low voltage unit are connected by the COM port for information exchange.The low-energy defibrillation simulation research is based on SCIRun simulation platform which was developed by Utah University of United Stages. The simulation simulates the voltage gradient and current density of heart region under different transthoracic impedances when defibrillation executes. This simulation aims at looking for lower energy in defibrillation.