Transthoracic Impedance Measurement System Applied to Automated External Defibrillators
QI Qi1,2, YU Ming1, GE Jianhui2, ZHANG Guang1, CHEN Feng1
1. Research Institute of War Wound Treatment and Medical Technology Support, Institute of Medical Support Technology, Academy
of System Engineering, Chinese PLA Academy of Military Sciences, Tianjin 300000, China; 2. Department of Sanitary Equipment
Supervision and Maintenance, Drug Instrument Supervision and Inspection Station, Wuxi Joint Logistic Support Center,
Chinese PLA Joint Logistic Support Force, Nanjing Jiangsu 210000, China
Abstract：Objective To explore a system that can reduce the excessive stimulation of electric current applied to patients by traditional
transthoracic impedance measurement method of automated external defibrillator (AED), increase the timeliness of transthoracic
impedance measurement and reduce the time interval between transthoracic impedance measurement and defibrillation.
Methods The transthoracic impedance measurement system was designed based on the circuit principle of AED and combined with
the defibrillation process. The system was composed of high voltage detection circuit, defibrillation current detection circuit, AD
acquisition and data processing. The characteristic of the system was that the transthoracic impedance was measured by the voltage
and current of defibrillation at the beginning of defibrillation discharge. Results The measurement error of the thoracic impedance
measurement system was less than 4 Ω after the simulation impedance measurement, which met the functional requirements of AED.
Conclusion This system effectively avoided the patients from receiving more unnecessary current stimulation, shortened the time
interval between measurement and defibrillation, and had better timeliness of measurement. It has certain reference significance for
the development of AED transthoracic impedance measurement technology.
