Performance of an automated external defibrillator in a moving ambulance vehicle.
OBJECTIVE
The available data suggest that automated external defibrillators (AED) can be safely used in vibration-like moving conditions such as rigid inflatable boats and aircraft environments. However, little literature exists examining their performance in a moving ambulance. The present study was undertaken to determine whether an AED is able to analyse the heart rhythm correctly during ambulance transport.


METHODS
An ambulance was driven on paved (20-100 km/h) and unpaved (10 km/h) roads. The performance of two AED devices (CU ER 2, CU Medical Systems Inc., Korea, and Heartstart MRx, Phillips, USA) was determined in a moving ambulance using manikins. Vibration intensity was measured simultaneously with a digital vibrometer. AED performance was then evaluated again on manikins and on a swine model under simulated vibration intensities (0.5-5m/s(2)) measured by the vibrometer in the previous phase of the investigation.


RESULTS
The vibration intensity increased with increasing speeds on paved roads (1.98+/-0.44 m/s(2) at 100 km/h). While driving on unpaved roads, it increased to 6.40+/-1.06 m/s(2). Both AED algorithms analysed the heart rhythm correctly under resting state. When tested on pigs, both algorithms showed substantially degraded performances, even at low vibration intensities of 0.5-1m/s(2), which corresponded to vibration intensities while driving on paved roads at 20-60 km/h. This study also showed that electrocardiograms generated on manikins were more resistant to motion artifacts than were the pig electrocardiograms.


CONCLUSIONS
Ambulance personnel should consider the possibility of misinterpretation by an AED when this device is used while transporting a patient.
Yun
Jong Geun
JG
Department of Emergency Medical Technician, Dongkang College, 160 Dongmunro, Bukgu, Gwangju, Republic of Korea. emt-jonggun@hanmail.net
Jeung
Kyung Woon
KW
Lee
Byung Kook
BK
Ryu
Hyun Ho
HH
Lee
Hyoung Youn
HY
Kim
Mu Jin
MJ
Heo
Tag
T
Min
Yong Il
YI
You
Yeonho
Y
D000552:Ambulances; D000818:Animals; D047548:Defibrillators / Q000592:standards*; D004562:Electrocardiography; D006339:Heart Rate; D008348:Manikins; D009038:Motion; D013552:Swine; D014732:Vibration