A new chest compression depth feedback algorithm for high-quality CPR based on smartphone.
BACKGROUND
Although many smartphone application (app) programs provide education and guidance for basic life support, they do not commonly provide feedback on the chest compression depth (CCD) and rate. The validation of its accuracy has not been reported to date. This study was a feasibility assessment of use of the smartphone as a CCD feedback device. In this study, we proposed the concept of a new real-time CCD estimation algorithm using a smartphone and evaluated the accuracy of the algorithm.


METHODS
Using the double integration of the acceleration signal, which was obtained from the accelerometer in the smartphone, we estimated the CCD in real time. Based on its periodicity, we removed the bias error from the accelerometer. To evaluate this instrument's accuracy, we used a potentiometer as the reference depth measurement. The evaluation experiments included three levels of CCD (insufficient, adequate, and excessive) and four types of grasping orientations with various compression directions. We used the difference between the reference measurement and the estimated depth as the error. The error was calculated for each compression.


RESULTS
When chest compressions were performed with adequate depth for the patient who was lying on a flat floor, the mean (standard deviation) of the errors was 1.43 (1.00) mm. When the patient was lying on an oblique floor, the mean (standard deviation) of the errors was 3.13 (1.88) mm.


CONCLUSIONS
The error of the CCD estimation was tolerable for the algorithm to be used in the smartphone-based CCD feedback app to compress more than 51 mm, which is the 2010 American Heart Association guideline.
1 School of Electrical Engineering, University of Ulsan , Ulsan, Korea.
Yeongtak
Y
Song
Jaehoon
J
Oh
Youngjoon
Y
Chee
D061725:Accelerometry; D000465:Algorithms; D016887:Cardiopulmonary Resuscitation / Q000592:standards*; D005246:Feedback; D006801:Humans; D063731:Mobile Applications; D011312:Pressure; D000068997:Smartphone
accelerometer; cardiopulmonary resuscitation; chest compression depth; smartphone