The use of dual accelerometers improves measurement of chest compression depth.

Background: Chest compression (CC) feedback devices are used to perform CC measurements effectively and accurately on patients in hospital beds. However, these devices do not take account of the compression of the mattress, which results in overestimation of CC depth. In this study, we propose a new method using two accelerometers to overcome this limitation and thus measure compression depth more accurately when performing cardiopulmonary resuscitation (CPR) on patients. Method: One accelerometer was placed on the manikin's sternum (a1), and the other between the manikin's back and the mattress (a2). The compression depth was calculated by integrating the acceleration twice using a digital signal processing technique. We compared CC depth from dual accelerometers and single accelerometer (a1) on the foam and inflated air mattress with eight CPR providers. Result: When CC was done on a manikin lying on the floor, there was no significant difference between measurement techniques (p > 0.05). When CC was done on a manikin lying on the foam and inflated air mattress supporting system, our method significantly improved the estimation of CC depth, irrespective of the presence or absence of a backboard (p < 0.001). Conclusion: Measuring CC depth using two accelerometers is more effective than using one in increasing the accuracy of CC depth estimation when CPR is performed on the foam and inflated air mattress, regardless of the presence or absence of a backboard. (C) 2011 Elsevier Ireland Ltd. All rights reserved.