It's sadly ironic that the very properties which make our skulls such excellent brain protectors, strength and rigidity, often work against us after head injuries. Not only does the hard bone conceal damage from concussions and bleeding, say, but it also confines the swelling, causing intra-cranial pressure to surge, a situation that can lead to further brain damage. While CT scans and magnetic resonance imaging systems are crucial to an accurate assessment, they are rarely available to emergency medical personnel at remote accident sites or on the battlefield. To help address the need for rapid and timely diagnosis of head traumas, separate research teams at the U.S. National Institutes of Health (NIH) and the Office of Naval Research (ONR) have each independently developed hand-held devices that use Near Infra-Red (NIR) imaging to quickly detect hematomas (internal bleeding) and other life-threatening traumatic brain injury (TBI).
The Centers for Disease Control in Atlanta, Georgia estimates that in the United States alone, roughly 1.4 million cases of TBI are diagnosed yearly. Of those, 50,000 will likely die from their injuries, many due to lack of proper diagnosis and early critical care in the crucial one hour period following the actual injury.
"When a brain injury occurs, every moment without an accurate assessment can determine a person's risk of severe injury or death due to a brain bleed," said Theresa Rankin, a TBI survivor and educator who works with Brain Injury Services, a Virginia-based non-profit advocacy group for head injury survivors.
Recently, the FDA approved the ONR device, called the Infrascanner, one of the first hand-held instruments capable of quickly detecting bleeding in and around the brain. Pooled blood absorbs near infra-red light differently than circulating blood, and this instrument senses that disparity. It's held stationary on several pre-determined cranial positions and must be kept very still for each 8-10 second reading period (moving it creates noise which can potentially interfere with accuracy). A linked PDA provides a visual interface, and the whole head can be assessed in as little as one to two minutes.
The NIH team's device, still in prototype stage, differs from the Infrascanner in that it is actually moved continuously over the cranium in the search for internal bleeding. It actually uses that motion-generated noise as a signal which can indicate changes in blood volume under or around the tough, leather-like membrane surrounding the brain (known as the dura mater - Latin for "hard or tough mother").
It's also able to detect the three different types of hemoglobin likely to be found in hematomas (oxy, deoxy and met-hemoglobin), helpful in distinguishing between chronic and acute situations. When it detects an area of pooled blood, a green light on the device illuminates to signal the operator.
Having instruments capable of rapid and accurate patient assessment available in the field or at the hospital provides a number of advantages to healthcare providers, speedy triage (the sorting of cases by severity) being a major one. Better triage also leads to more efficient use of costlier diagnostic equipment (CT/MRI scans) and translates to more appropriate care earlier on - something that ought to help boost survival rates for brain injury victims in the not-too-distant future.
See the video below to learn how the Infrascanner is deployed.
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