Researchers from the Caltech and the Keck School of Medicine of the University of Southern California have developed an innovative wearable laser device. It could revolutionize the approach to stroke risk assessment. The device monitors changes in cerebral blood flow during a patient's breath-hold, allowing real-time analysis. Laser light is passed through the skull, and a camera collects data on the light reflecting off the blood vessels. This technique, known as speckle-contrast optical spectroscopy (SCOS), reveals blood flow velocity and changes in blood flow. The bandage provides instant feedback on a person's condition, offering a portable, affordable and non-invasive way for doctors to perform important medical interventions. Fifty people participated in testing the device and were divided into high- and low-risk groups based on the results of a questionnaire. Participants held their breath for one minute, which stressed the brain and allowed the device to analyze vascular response. In the future, the researchers plan to implement machine learning to analyze the data and conduct clinical trials. According to experts, the technology can help not only in risk assessment, but also in determining the location of a stroke that has already occurred.