Volumetric impedance phase shift spectroscopy (VIPS) detects stroke in 30 seconds
The Cerebrotech Visor, a new device worn like a visor, can detect emergent large-vessel occlusion in patients with suspected stroke with 92 percent accuracy, report clinical investigators at the Medical University of South Carolina (MUSC), Mount Sinai, the University of Tennessee Health Sciences Center and elsewhere in an article published in the Journal of Neurointerventional Surgery.
The volumetric impedance phase shift spectroscopy (VIPS) device works by sending low-energy radio waves through the brain that change frequency when passing through fluids. Such waves are reflected back through the brain and then detected by the device. When a patient is having a severe stroke, the brain’s fluids will change, producing an asymmetry in the radio waves detected by the VIPS device. The greater the asymmetry, the more severe the stroke.
The Cerebrotech Visor is a noninvasive wireless device for assessing brain fluid distribution. The Visor uses low-power radio waves to detect bioimpedance asymmetry, including asymmetry associated with large acute ischemic stroke in patients undergoing neurologic assessment. In recent clinical studies, the Visor has been able to differentiate large strokes from small strokes with an accuracy over 90%, a study found.
In the study, the VIPS device was deployed with emergency medical personnel in regions served by five Comprehensive Stroke Centres equipped with the endovascular capabilities to treat large-vessel occlusions that underlie severe stroke. Their goal was to use the device to accurately identify severe stroke and then compare the results to established physical examination methods practiced by emergency personnel such as the Prehospital Acute Stroke Severity Scale.
Both healthy participants and patients with suspected stroke were evaluated by emergency personnel using the VIPS device. Three readings were taken and averaged—a process that takes about 30 seconds. Patients were also later evaluated by neurologists who provided definitive diagnoses using neuroimaging.
Compared to the neurologists’ diagnoses, the device displayed 92 percent specificity—the ability to detect the difference between patients with severe stroke and those with other conditions such as mild stroke or healthy participants with no brain pathology. This places the VIPS device above standard physical examination tools used by emergency personnel that display specificity scores between 40 and 89 percent.