Mobile Microwave Helmet Enables Rapid, Accurate Diagnosis Of Stroke Cause

By Joel Lindsey

Swedish researchers from Chalmers University of Technology, Sahlgrenska Academy, and Sahlgrenska University Hospital have created a new device that can rapidly determine whether a stroke has been caused by a blood clot or from internal bleeding caused by a burst blood vessel.

According to a news article published recently by NPR, the device — which is called Strokefinder — consists of 12 antennas that are arranged around the head like a helmet. Taking turns, each antenna sends low-powered microwaves through the skull while the other 11 detect changes in the waves as they pass through the brain. The device then analyzes these changes in order to detect cranial bleeding. The entire process can be completed in a matter of seconds.   

“Our goal with Strokefinder is to diagnose and initiate treatment of stroke patients already in the ambulance,” Mikael Elam, professor of clinical neurophysiology at Sahlgrenska University Hospital, said in a press release published recently by Chalmers University. “Since time is a critical factor for stroke treatment, the use of the instrument leads to patients suffering less extensive injury. 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.”

The ability to accurately and quickly distinguish between a stroke that has been caused by a blood clot or one caused by bleeding is critical because it determines the type of treatment that should be administered. In strokes caused by blood clots, treatment usually consists of clotbusting drugs, but these same drugs could lead to catastrophic complications if administered to a person whose stroke is the result of bleeding.

Time is also a crucial concern in the treatment of strokes, since the longer a person experiences a stroke the more likely that person is to sustain serious damage to brain cells.

Researchers involved with the project say that their new device could make quick and accurate diagnoses possible without the need for expensive and largely immobile CT scanners. This could make Strokefinder particularly useful for hospitals in rural locations or in economically underprivileged areas.

In initial clinical studies, the results of which were published recently in the journal IEEE Xplore, Strokefinder was used on 45 stroke patients, and it correctly identified the 19 patients whose strokes had been caused by bleeding.

“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 Mikael Persson, a professor of biomedical engineering at Chalmers University who is involved with the project.

In these tests, however, the device also gave five false positives. The research team plans to improve the helmet’s analytical algorithms in order to reduce these occurrences, according to NPR. They also hope to conduct an ambulance trial later this year.

Image credit: Gunilla Brocker