Toward Miniaturization of Defibrillators: Design of a Defibrillation Charge/Discharge Circuit

Sudden cardiac death (SCD) is caused by a change in heart rhythm. Ventricular fibrillation (VF) is the most common cause of SCD, and electrical defibrillation is the most effective method of terminating VF. Miniaturization of defibrillators has extraordinary significance. In this study, we proposed a miniaturized design for the defibrillator charge/discharge circuit. The core circuit, composed by low-operating-voltage and surface-mount elements, achieved a size of 4.9 cm × 4.9 cm. We specially designed a voltage management system to power the system by a low-voltage battery. The proposed circuit could quickly charge the storage capacitor to 800 V within 8 s and release a biphasic exponential truncated waveform whose pulse width and delivered energy could be adjusted flexibly. With further optimization and suitable batteries and capacitors, this defibrillator charge/discharge circuit can be used for miniaturized wearable cardiac defibrillators (WCDs) and implantable cardioverter defibrillators (ICDs).