http://www.digitaljournal.com/tech-and-science/science/lasers-developed-for-non-invasive-cancer-diagnosis-and-treatment/article/550134

Lasers developed for non-invasive cancer diagnosis and treatment

Posted May 19, 2019 by Tim Sandle
Scientists have developed a new way to assess a human for signs of diseases, using lasers for a novel non-invasive approach. This is based on a new laser microscope that has been initially tested out to assess for signs of skin cancer.
Graphene enables ultrafast laser pulses for spectroscopy and biomedical applications.
Graphene enables ultrafast laser pulses for spectroscopy and biomedical applications.
Andrew Adams (CC BY-SA 2.0)
The new approach comes from the University of British Columbia, and here Canadian scientists have built a specialized microscope with the functionality to diagnose for diseases like skin cancer and to have the capability to perform incredibly precise surgery. Both approaches are based on laser technology and neither require the cutting of skin.
The technology is based on a specialized type of multiphoton excitation microscope. When excitation occurs, two photons of infrared light are absorbed. By using infrared light, this serves to minimize the scattering in the tissue. Furthermore, because of the multiphoton absorption, the background signal is strongly suppressed. Coming together these two effects lead to an increased penetration depth.
This device enables medics to produce precise images of living tissue to the level of one millimeter in depth. This is based on the manipulation of an ultrafast infrared laser beam. The device is capable of digitally scanning living tissue and then treating the tissue by intensifying the heat produced by the laser.
The research has shown that when applied to treating diseases of the skin, the laser-powered microscope enables scientists to accurately pinpoint the location of an abnormality, diagnose it and then to treat it instantly. In theory this technology could be used to treat any structure of the body that is reached by light, such as nerves or blood vessels in the skin, eye, brain or other fragile structures.
According to lead scientist, Yimei Huang: "Our technology allows us to scan tissue quickly, and when we see a suspicious or abnormal cell structure, we can perform ultra-precise surgery and selectively treat the unwanted or diseased structure within the tissue -- without cutting into the skin."
An illustration of the technology in action is shown in the following video:
The development of the lasers and the first phase of testing are described in the journal Science Advances. The peer reviewed paper is titled "Precise closure of single blood vessels via multiphoton absorption–based photothermolysis."