A helmet that uses microwaves to examine brain tissue has been found to accurately diagnose the type of stroke that a patient has suffered. If developed, the device could lead to early and correct diagnosis of stroke and may improve treatment for what is currently the 4th highest cause of death in the US.
According to the American Heart Association (AHA), there are 137,000 deaths a year due to stroke. Around 795,000 Americans suffer a stroke each year.
There are two main types of stroke: ischemic strokes, caused by an obstruction to the flow of blood such as a blood clot, and hemorrhagic strokes, caused by the rupture of an artery that feeds the brain. Both types of stroke result in a lack of blood being able to get to the brain of the sufferer.
The outcome of a stroke depends on where the stroke occurred and how much of the brain is affected. It can lead to paralysis, memory loss, problems with vision, problems with speech and death.
These two types of stroke require different kinds of treatment. Ischemic strokes are usually caused by blood clots and are treatable with clot-dissolving medicine. However, this type of medicine is harmful to those who have suffered from hemorrhagic strokes.
A quick diagnosis is vital
The current problem is that external symptoms alone do not indicate what type of stroke someone has suffered. Treatment cannot begin until this diagnosis has been made, and at present this is done using a CT scan in a hospital.
A swift diagnosis means quick treatment and reducing the potential damage that a stroke can cause. This is what researchers from Sweden are hoping a new piece of technology will be able to provide.
The researchers state that acute thrombolytic treatment can dramatically reduce or abolish the symptoms of ischemic stroke. Also, a system that can be used to make a diagnosis prior to the patient arriving at a hospital will allow for this treatment to be utilized quickly.
Clot-dissolving medicine must be administered within 4 hours of the stroke's onset in order to be effective.
A prototype of the Strokefinder microwave helmet. The team are currently working on a mobile version of the device to use in ambulances.
Image credit: Gunilla Brocker
The researchers from Chalmers University of Technology, Sahlgrenska Academy and Sahlgrenska University Hospital tested two prototypes of the "Strokefinder" helmet. Strokefinder is a device that can determine whether a stroke is caused by a blood clot or bleeding by using microwaves to examine the brain's tissue.
The system is also self-learning, and so its diagnoses will become increasingly reliable over time as more patients are examined.
The researchers tested their prototypes on 45 stroke patients who had arrived at the hospital in a stable condition following initial assessment and treatment. This trial found that Strokefinder can successfully distinguish clots from bleeding, and bleeding subjects from healthy subjects.
The study is published in the IEEE Transactions on Biomedical Engineering journal.
'A major achievement'
Mikael Persson, professor of biomedical engineering at Chalmers University of Technology, says that these results show that they will be able to increase the number of stroke patients who receive optimal treatment when the instrument makes a diagnosis in an ambulance.
"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."
The wider benefits of this research are outlined further by Mikael Elam, professor of clinical neurophysiology at Sahlgrenska University Hospital:
"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."
A mobile version of the Strokefinder is currently being completed in order to test the equipment in ambulances. Further studies also need to be carried out to compare the new system with CT scanning before the device can be used routinely.