(PhysOrg.com) -- Researchers from the VCU Reanimation Engineering Shock Center, VCURES, have developed a new technique for rapidly determining the severity of hypovolemia - the abnormal decrease in blood volume caused by trauma - based on a new approach of analyzing electrocardiogram signals.
Soo-Yeon Ji, Ph.D., and Kayvan Najarian, Ph.D., of VCU’s Department of Computer Science, and Kevin Ward, M.D., associate professor in the Department of Emergency Medicine, studied 22 healthy volunteers who underwent lower body negative pressure to simulate moderate-to-severe hemorrhage by moving blood from the upper body into the dependent areas of the pelvis and leg.
The subjects wore a wireless electronically enabled elastic armband capable of capturing ECG signals. The device is made by BodyMedia Advanced Development.
Najarian, who is associate director of VCURES, led the team’s application of a technique called discrete wavelet transform (DWT) to analyze the low-level ECG signals. The DWT technique is an advanced computational method allowing extraction of invisible variations of the ECG that are not detectable by the human eye. In the study, the technique was demonstrated to have accuracy between 80 percent and 90 percent in predicting the severity of blood loss.
According to Ward, traditional vital signs such as blood pressure and heart rate are notoriously deceiving in attempting to determine the severity of hypovolemia until the patient becomes critically unstable. He also said the technology may be capable of providing earlier information on the patient’s status allowing intervention before the patient becomes too unstable.
“This is a great example of what can happen with collaboration between the engineering and medical science promoted by VCURES,” said Najarian. “We are analyzing additional signals that can be obtained by the arm band that we believe will enable the device to effectively serve as a wearable wireless critical care monitor.”
The study was performed in collaboration with the U.S. Army Institute of Surgical Research based at Ft. Sam Houston in San Antonio and BodyMedia Advanced Development of Pittsburgh.
“Hemorrhage is the leading cause of death in civilian and combat trauma,” said Ji. “Yet determining the severity of hypovolemia can be a challenge especially in an active battlefield or among mass casualties.”
“The fact that we can use a simple existing biologic signal like the ECG obtained with a small device quickly placed on the upper arm, means precious time and resources can be saved,” added Ward. “The earlier we can intervene, the better the potential outcome. We envision the device and analysis technique to be useful for paramedics, combat medical personnel, emergency departments, operating rooms and intensive care units.”
An abstract of the study was presented at the 2009 American Heart Association Resuscitation Science Symposium, where it was awarded Best Trauma Abstract.
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