Laser

Lasers have a variety of applications in the field of medicine. Using laser beams whose wavelength is absorbed strongly, surgeons can cut and remove tissue with great precision by vaporizing it, with little damage to the surrounding tissue. The systems are used in minimally-invasive surgical techniques such as angioplasty (removing plaque from artery walls) and lithotripsy (the destruction of kidney stones in the bladder), in which a hair-thin optical fiber feeds light into the body through a tiny incision; the small opening required for the fiber results in reduced scarring and shorter healing times. In a technique called photorefractive keratectomy, lasers are routinely used to correct myopia and astigmatism. Other medical applications include removal of birthmarks, tattoos, and small varicose veins from the skin; welding tissue and sealing blood vessels during surgery; or resurfacing skin to minimize wrinkles or sun damage.

Cutting-edge researchers are using visible and infrared lasers to increase bloodflow to oxygen-starved regions of the heart, to visually detect cancer cells on the skin's surface, or to image through the skin to monitor bloodflow or detect cancerous regions. In a technique called photodynamic therapy, laser light activates a drug that accumulates in certain types of tumors, causing the drug to destroy the cancerous tissue. A sophisticated diagnostic technique called spectroscopy takes advantage of the fact that cancerous tissue reflects light differently than non-cancerous tissue, allowing doctors to identify skin cancer and cervical cancer. A laser-based optical mammography system is even under development.