007 laser used in modern medicine
007 laser used in modern medicine
October 31, 2007
The Press Association
Scientists have conducted the first investigation of the way laser light interacts with living tissue.
The purpose was not to devise more interesting ways to despatch secret agents - as used by Goldfinger on James Bond - but to improve the use of lasers in medicine.
Lasers are increasingly replacing steel bladed scalpels in numerous procedures ranging from brain ops to cosmetic surgery.
The effect powerful lasers have on flesh varies both with the light's colour, or wavelength, and the duration of the pulses they produce, said the researchers.
Mid-infrared lasers with long wavelengths cut by burning, heating tissue to the point where the chemical bonds holding it together break down. Because they automatically cauterise the wounds they make, infrared lasers are often used when there is a lot of bleeding.
Shorter wavelength lasers in the visible and ultraviolet range cut by an entirely different mechanism, the study found. They create a series of micro-explosions that break the molecules apart.
These lasers, especially the ultraviolet ones, can cut more precisely and produce less collateral damage. They are especially suitable for eye surgery, delicate brain surgery, and microsurgery.
US expert Dr Shane Hutson, from Vanderbilt University in Nashville, Tennessee, who led the research, said: "This is the first study that looks at the plasma dynamics of ultraviolet lasers in living tissue. The subject has been extensively studied in water and, because biological systems are overwhelmingly water by weight, you would expect it to behave in the same fashion. However, we found a surprising number of differences." .
One surprise was that ultraviolet lasers need to be far less powerful than was previously thought to cut flesh effectively.
The findings are published in the journal Physical Review Letters.
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