Biomedical engineers have developed a new technique for measuring blood flow in the human brain which could be used in patients with stroke or traumatic brain injury. The technique, based on conventional digital camera technology, could be significantly cheaper and more robust than prior methods. The work is described in a paper that was published on April 26 in the journal, Optica . If you shine a light into a cloudy solution, light particles, or photons, will be scattered in different directions. An experimental technique called diffuse correlation spectroscopy, or DCS, essentially uses this approach to look inside someone’s skull. Laser light is shone on the head; as photons from the laser pass through the skull and brain, they are scattered by blood and tissue. A detector placed elsewhere on the head, where the photons make their way out again, picks up the light-fluctuations due to blood motion. These fluctuations then provide information about blood flow. The researchers have called the method interferometric diffusing wave spectroscopy, or iDWS.
