In medicine, there is, if not a problem, then the task of disinfecting catheters and similar equipment, which is designed for long-term contact with the human body. When the catheter is inserted, the skin is pierced, a hole in the protection is literally formed, which creates the risk of infection. At Columbia University, they proposed a technology for sterilizing catheters right at the time of work, without harm to the patient.
Ultraviolet radiation is harmful to microbes, this fact, but it is dangerous for human eyes and skin too. Therefore, direct disinfection by irradiating living people with UV light is not recommended. However, scientists from Columbia University managed to find a narrow band of the spectrum, when UV radiation still kills microbes, but already too weak to penetrate the dead outer layer of the skin or the mucous membrane of the eye. A weapon against bacteria, harmless to humans.
But how to deliver UV rays precisely into the wound, into a tiny area already filled with a catheter installed there? Through a modified fiber that is flexible and reflective so that light is partially emitted outward as it travels through the fiber. When the fibers were passed through a tube containing cultures of microbes resistant to Staphylococcus aureus methicillin, the bacteria died along the entire length of the fibers after applying UV radiation. All that remains is to mount the optical fiber into the catheter itself and periodically turn on the ultraviolet light to sterilize the puncture in the patient's skin.
So far, scientists are just preparing for experiments on animals, plus they are thinking about how to make generators of special UV radiation compact and cheap. However, the discovery itself is encouraging - a new method of sterilization may give impetus to the creation of new medical instruments.