Software for Alerting Health Care Providers of Potential Stroke

On February 13, 2018, the FDA permitted marketing of the Viz.AI Contact application, a type of software designed to analyze computed tomography (CT) images of the brain and notify health care providers of a potential stroke in their patients.


A stroke is a serious medical condition that requires emergency care and can cause lasting brain damage, long-term disability, or even death. A stroke occurs if the flow of blood to a portion of the brain is blocked. According to the CDC, stroke is the fifth leading cause of death in the U.S. and is a major cause of serious disability for adults. Approximately 795,000 people in the U.S. have a stroke each year.


“Strokes can cause serious and irreversible damage to patients. The software device could benefit patients by notifying a specialist earlier thereby decreasing the time to treatment. Faster treatment may lessen the extent or progression of a stroke,” said Robert Ochs, Ph.D., the acting deputy director for radiological health in the Office of In Vitro Diagnostics and Radiological Health, which is part of the FDA’s Center for Devices and Radiological Health.


The Viz.AI Contact application is a computer-aided triage software that uses an artificial intelligence algorithm to analyze images for indicators associated with a stroke. These artificial intelligence algorithms, known as clinical decision support software, assist health care providers in identifying the most appropriate treatment plan for a patient’s disease or condition. The FDA is currently creating a regulatory framework for clinical decision support software that encourages developers to create, adapt, and expand the functionalities of the software to aid providers in diagnosing and treating diseases and conditions.


The Viz.AI Contact application is designed to analyze CT images of the brain and send a text notification to a neurovascular specialist when a suspected large vessel blockage has been identified. The algorithm will automatically notify the neurovascular specialist while the radiologist is conducting a standard review of the images. The automatic notification may engage the specialist sooner than the usual process, in which patients wait for a radiologist to review CT images and notify a neurovascular specialist.


The Viz.AI Contact application is intended to be used by neurovascular specialists, such as vascular neurologists, neuro-interventional specialists, or other professionals with similar training. The application is limited to analysis of imaging data and should not be used as a replacement for a full patient evaluation or solely relied upon to make or confirm a diagnosis.


Viz.AI submitted a retrospective study of 300 CT images that assessed the independent performance of the image analysis algorithm and notification functionality of the Viz.AI Contact application against the performance of two trained neuro-radiologists for the detection of large vessel blockages in the brain. Real-world evidence was used with a clinical study to demonstrate that the application could notify a neurovascular specialist sooner in cases where a blockage was suspected.


See the FDA Announcement


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