The microwave helmet can be used for rapid detection of intracranial hematomas in patients with traumatic brain injuries

From left: Stefan Candefjord, Mikael Elam, Lars Jönsson, Johan Ljungqvist, Thomas Skoglund, Mikael PerssonIn a recently published scientific article, researchers from Chalmers University of Technology, the Sahlgrenska Academy at the University of Gothenburg, and the Sahlgrenska University Hospital, present results from the initial patient studies that were completed in 2016.

The study shows a new application for microwave technology in health care. Microwaves have previously been used to distinguish stroke caused by bleeding from stroke caused by a clot. This new study shows that the technology can also be used in patients with traumatic brain injury – the most common cause of death and disability among young people. Traumatic brain injury is often caused by traffic accidents, assaults or falls, and an estimated 10 million people are affected annually.


Johan Ljungqvist, you are the first author of the article, what can you tell us about the study?

– The study compared 20 patients admitted for surgery of chronic subdural hematoma – a particular type of intracranial bleeding – with 20 healthy volunteers, says Johan Ljungqvist, specialist in neurosurgery at the Sahlgrenska University Hospital. The patients were examined with the microwave helmet and the measurements were then compared with traditional CT scans. The results show that the microwave instrument has great potential to detect intracranial bleeding in this group of patients. The result is very promising even though the study is small and only focused on one type of head injury.


How could the microwave helmet make a difference for the patients?

– The microwave helmet could improve the medical assessment of patients with traumatic brain injuries by detecting intracranial hematomas even before the patient arrives to hospital, says Johan Ljungqvist. The microwave helmet could be used in air- and road ambulances, and thereby improve early triage and reduce the time from injury to operation which is key to reduce mortality and improve outcome. Transporting patients to the appropriate level of care is also cost efficient.

How does the microwave helmet work?

– The system consists of three parts: A helmet-like antenna system that is put on the patient’s head, a microwave unit and a computer that is used to control the equipment, data acquisition and signal processing. The antennas of the helmet sequentially transmit weak microwave signals into the brain, says Mikael Persson, executive board member at MedTech West and professor in Signal Processing and Biomedical Engineering. At the same time, the receiving antennas listen for reflected signals. The brain’s different structures and substances affect the microwave scattering and reflections in different ways. The received signals are interpreted with the help of advanced algorithms.


What role has MedTech West played in the microwave helmet project?

– It is challenging to develop a new diagnostic principle, from early laboratory tests to a device suitable for clinical use in a hyperacute clinical environment where the immediate care of patients cannot be delayed, says Mikael Elam, executive board member at MedTech West and professor in Clinical Neurophysiology. It requires a sustained close collaboration between technical and medical professionals, built on mutual trust and a common language, and the role of MedTech West is to facilitate the formation of such multi-disciplinary med-tech teams.


Further studies on patients with traumatic brain injury are ongoing and planned in Sweden as well as abroad. Before the microwave helmet can be used routinely for diagnosis in ambulances, larger comparative studies with computed tomography must be conducted.


First author Johan Ljungqvist will be defending his doctoral thesis on “Diagnostic Methods in Traumatic Brain Injury” including the above menitioned paper later this spring. The authors of the article are:

Johan Ljungqvist,1,2 Stefan Candefjord,3,4,5 Mikael Persson,3,4 Lars Jönsson,6 Thomas Skoglund,1,2 and Mikael Elam4,7
1Department of Neurosurgery, Sahlgrenska University Hospital, Gothenburg, Sweden.
2Institute of Neuroscience and Physiology, Department of Clinical Neuroscience, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
3Department of Signals and Systems, Chalmers University of Technology, Gothenburg, Sweden.
4MedTech West, Sahlgrenska University Hospital, Gothenburg, Sweden.
5SAFER Vehicle and Traffic Safety Centre at Chalmers, Gothenburg, Sweden.
6Department of Neuroradiology, Sahlgrenska University Hospital, Gothenburg, Sweden.
7Department of Clinical Neurophysiology, Sahlgrenska University Hospital, Gothenburg, Sweden.


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Text: Helene Lindström
Photo: Henrik Mindedal