Microwave Helmet Provides Accurate Diagnosis of Stroke

Microwaves can be used for rapid diagnosis of stroke, as well as for differentiating between hemorrhagic and ischemic-induced strokes.

Researchers at Chalmers University of Technology (Göteborg, Sweden), Sahlgrenska Academy (Göteborg, Sweden), and Sahlgrenska University Hospital (Göteborg, Sweden) conducted a study involving 45 patients to examine the proof-of-principle of the prototype Strokefinder device, which consists of an array of 12 antennas arranged around the head on a helmet. One by one, each antenna beams a low-power microwave signal through the skull, while the other 11 detect how the signal has changed after scattering through the brain.

The microwave measurements are analyzed with a machine-learning algorithm calibrated by training data from patients with known conditions, using computerized tomography (CT) scans as reference. The results revealed that the Strokefinder correctly identified all 19 patients suffering from cranial bleeding. However, it identified five false positives that indicated that patients might have cranial bleeding, when they were actually suffering from a blood clot. The researchers said that with further trials on patients, the algorithms can be improved to decrease the false positive rate. The study was published on June 16, 2014, in IEEE Transactions on Biomedical Engineering.

“The results of this study show that we will be able to increase the number of stroke patients who receive optimal treatment when the instrument makes a diagnosis already in the ambulance,” said lead author Professor of Biomedical Engineering Mikael Persson, PhD, of Chalmers University of Technology. “The possibility to rule out bleeding already in the ambulance is a major achievement that will be of great benefit in acute stroke care. Equally exciting is the potential application in trauma care.”

“Our goal with Strokefinder is to diagnose and initiate treatment of stroke patients already in the ambulance. Since time is a critical factor for stroke treatment, the use of the instrument leads to patients suffering less extensive injury,” added corresponding author professor of clinical neurophysiology Mikael Elam, MD, PhD, of Sahlgrenska University Hospital. “This in turn can shorten the length of stay at hospitals and reduce the need for rehabilitation, thus providing a number of other positive consequences for both the patient and the health care system.”

Related Links:
Chalmers University of Technology
Sahlgrenska Academy
Sahlgrenska University Hospital