A Transthoracic Impedance Measurement System Applied to External Automatic Defibrillators

The transthoracic impedance measurement is one of the important functions of an automated external defibrillator (AED). In this paper, the basic knowledge of transthoracic impedance measurement is introduced, and a simple transthoracic impedance measurement system combined with the defibrillation process is proposed. The system is composed of a high voltage detection circuit, defibrillation current detection circuit, AD acquisition and data processing and other parts, without additional hardware excitation measurement structure, which is conducive to the portable design of AED. The measurement results show that the error of transthoracic impedance measured by this system is less than 5%.