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Experimental Device May Help EMS Detect Subdural Hematomas and TBI

Issue 3 and Volume 42.

Brain Waves

Candefjord S, Winges J, Malik AA, et al. Microwave technology for detecting traumatic intracranial bleedings: Tests on phantom of subdural hematoma and numerical simulations. Med Biol Eng Comput. Oct. 13, 2016. [Epub ahead of print.]

One of the most challenging aspects of prehospital medicine is the relatively limited selection of diagnostic tools available to us. As a profession, we pride ourselves as clinicians who can combine a history and physical assessment to form a reasonably accurate differential diagnosis.

Patients with vague or nonspecific symptoms, such as stroke, subdural hematoma and traumatic brain injury (TBI) can be a challenge to accurately diagnose. This month’s cutting-edge technology review is truly the “bleeding edge” (pun intended) of experimental laboratory research in prehospital care.

In this study, Swedish researchers simulated a subdural hematoma by putting blood in a plastic brain to see if a headset equipped with microwave technology (MWT) could detect it.

Background: High-risk individuals, such as the elderly or those on anticoagulant therapy, may suffer from a subdural hematoma from very minimal trauma and present with little or no symptoms.

Although mortality remains high for patients with subdural hematomas, early detection and transport to a facility with neurosurgical capability could increase survival. Kudos to the study’s authors for thinking outside the box in their investigation of a more objective and reliable detection method.

Methods and results: A plastic skull was created using a 3-D printer, and filled with brain and blood to simulate a subdural hematoma. A helmet outfitted with 12 MWT antennas was then used in an attempt to detect the presence of the simulated hematoma. To account for the variability that exists in the prehospital setting, the helmet was removed and replaced many times. The simulated anatomy was also modified throughout the study to see if different size hematomas could be detected. Impressively, the MWT had a 100% sensitivity and 96% specificity in detecting the presence of the subdural hematoma.

Discussion: Although the results are promising, it’s still early to bring the technology to market. This was a simulated lab experiment with plastic and simulated blood. Supportive evidence from a cadaveric study may lead to a human trial, which can ultimately lead to the development of a product that could be available for EMS crews to better assess patients with suspected hematomas and TBI.

Bottom Line

What we already know: Trials are underway using multiple technologies to identify concussions, TBI and strokes. The use of blood-based point-of-care biomarkers (measured with devices such as the i-STAT),1 transcranial doppler (TCD) using ultrasound and eye tracking helmets,2,3 and cognitive assessment tools such as SCAT3 (sport concussion assessment tool),4,5 and imPACT computerized assessments show increased promise of detecting brain injury.

What this study adds: Microwave technology is a novel diagnostic method that might assist EMS in detecting intracranial bleeding.


1. Hodsden S. Abbott teams with Minnesota researchers to launch world’s largest single-centered TBI study. Med Device Online. Retrieved Jan. 29, 2017, from

2. American Academy of Neurology. Ultrasound headset may be new way to recognize concussion on the sidelines. Med Device Online. Retrieved Jan. 29, 2017, from

3. Samadani U. A new tool for monitoring brain function: eye tracking goes beyond assessing attention to measuring central nervous system physiology. Neural Regen Res. 2015;10(8):1231–1233.

4. Bin Zahid A, Hubbard ME, Dammavalam VM, et al. Assessment of acute head injury in an emergency department population using sport concussion assessment tool: 3rd edition. Appl Neuropsychol Adult. Nov. 17, 2016. [Epub ahead of print.]

5. Consensus statement: SCAT3. Br J Sports Med. 2013;47:259. Retrieved Jan. 29, 2017 from


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