BEIJING, May 22 (Xinhua) -- Researchers from China and Canada have developed a new highly targeted laser device to close blood vessels within human tissue.

Reporting on the U.S. journal Science Advances, they said the device has the potential to diagnose diseases including skin cancer and perform precise surgery without cutting the skin.

According to researchers from the University of British Columbia in Canada and China's Fujian Normal University, the device, using an ultrafast infrared laser beam, allows imaging of living tissue up to about 400 microns for skin tissue and one millimeter for brain tissue.

When applied to treat skin diseases, the device allows doctors to pinpoint the exact location of the disease, diagnose and treat it instantly.

Using the device, researchers can selectively close single blood vessels of varying size ranging from capillaries to venules in a mouse ear model. It can close blood vessels within tissue while preserving the overlying superficial ones.

The device, called "multiphoton excitation microscope," uses a focused laser beam to aim at the center of the targeted vessel, generating localized heat. The heat, spreading to the wall of the blood vessel, causes it to collapse and close.

Although the power density from the laser is very high, it is only aimed at the focal point. The nearby vessels thus remain unaffected.

The researchers said the device can be used to treat any structure of the body that can be reached by light and that requires extremely precise treatment, including nerves or blood vessels in the skin, eye, brain or other vital structures.