A microwave helmet can help doctors make quicker and more accurate diagnoses of patients who have had strokes which can help counter brain damage, Swedish researchers said Tuesday.

In a study involving 45 patients last year, researchers at the Chalmers University of Technology, Sahlgrenska Academy and Sahlgrenska University Hospital in western Sweden found that the microwave technique allows doctors to determine whether patients have strokes caused by bleeding as opposed to those caused by blood clots.

As a result, the researchers said more effective, quicker treatment can be given to patients as they transported by ambulance to the hospital.

The helmet, which the researchers call Strokefinder, uses microwaves to examine brain tissue and interprets the signals to determine what type of stroke a patient has had. The system also stores information and builds a database to help with future diagnoses.

Two helmet prototypes were tested at Chalmers and Sahlgrenska. This fall, they will be tested in the field on stroke patients who are being brought by ambulance to hospitals.

"Our goal 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 statement.

He added that since time is a critical factor in stroke treatments, the use of the instruments 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," Elam said.

The plan is to develop the helmet for commercial use through a company which was spun off from the research department at Chalmers. The researchers said further testing is needed on a larger group of patients before the helmet can be used commercially.