Abstract 253: Accuracy of Detecting Chest Compression Rate from the Thoracic Impedance Data Recorded Through Chest Pads
To assist healthcare providers in performing quality CPR, devices such as Q-CPRTM measurement and feedback tool can be used with defibrillators. However, such devices are not always present, but almost every defibrillator records impedance signal through chest pads. Therefore, being able to detect the chest compression (CC) rate from the thoracic impedance signal in real-time can be valuable in practice. The real-time rate, for example, can be used to provide feedback to the rescuer or to remove compression artifact from ECG during CPR to shorten the time between last compression and the defibrillation shock.
To detect the chest compression rate from thoracic impedance signal and compare it to the true rate from compression signal.
Recordings of 175 out of hospital cardiac arrest (OHCA) patients older than 18 years were used. The database was collected using Laerdal HeartStart 4000 defibrillators in 6 ambulances in 3 European regions between March 2002 and October 2003 for prospective study of OHCA patients. The defibrillators had an extra chest pad mounted on the lower part of the sternum with an accelerometer and a pressure sensor to record the compression signal which by analyzing it the true compression rate was determined. The thoracic impedance signal from the chest pads was also recorded and analyzed to calculate the compression rate.
At the end of each 10-second segment of the data the compression rate was calculated from the thoracic impedance and was compared to the true rate in the same interval. The difference between the true and calculated rate was 2±13 compression per minute (cpm). For 95% of the data segments the difference was lower than 20 cpm, and only 9% of the segments had a rate difference larger than 10 cpm.
In the absence of CPR measurement and feedback tools, it is possible to accurately detect the chest compression rate using only the thoracic impedance signal which is usually recorded through the defibrillator chest pads. This can potentially be used as a software-only CPR feedback tool to help improve the quality of CPR delivery. However, unlike devices such as Q-CPRTM, this method does not give any feedback on the compression depth or ventilation volume and rate.
- Cardiopulmonary resuscitation
- Cardiac arrest
- Sudden cardiac death
- Quality assessment
- © 2012 by American Heart Association, Inc.