Shedding New Light on Wound Healing

Today, doctors who really want to see if a wound is healing have to do a biopsy or some other invasive technique, which means effectively injuring an already injured patient. But there is a tool that could do this job non-invasively. It’s called hyperspectral imaging (HSI), and it involves collecting light reflected off of skin.

Different kinds of tissue have distinctive light signatures, or spectra, that can be used to identify them. In theory, doctors could use HSI to tell healthy tissue from diseased, for use in examining burns, chronic wounds, and the margins of tumors during surgery.

Many physicians would prefer to use completely non-invasive HSI methods over an invasive biopsy. But HSI isn't being used routinely in the clinic yet because standards are not in place for this technology.

“Individual researchers doing their own experiments show positive results,” said NIST researcher David Allen. “But when you start comparing an instrument in one lab to an instrument in another, the data are typically inconsistent.”

Now NIST researchers have taken a step towards making these standards possible. They have produced the first prototype tissue “phantoms,” which are proxies for the body or its components. In this case, the phantoms are digital: a set of spectral signatures and images that correspond to different states related to blood flow within tissues.

Currently, accumulating the data for these digital phantoms is a time-consuming process: Each scan takes from tens of seconds to a minute or more. "But in the future, we'll have 'snapshot' hyperspectral scans for real-time imaging, including video,” Allen said. “Eventually, we want to get to the point at which you can see the blood perfusing through the tissue."