Scientists discover key to invisibility
By Roger Highfield, Science Editor
http://www.telegraph.co.uk/et?ac=000118613908976&rtmo=lnvlFHPt&atmo=rrrrrrvs
&pg=/et/00/8/23/wskin23.html#top
THE invisible man has come one step closer: scientists believe they have
found a way to make flesh transparent for a few minutes at a time.
By manipulating the way light passes through tissue, a team at the
University of Texas at Austin has moved into what was once the realm of
science fiction. The engineers say they can create a temporary "window" in
tissue, allowing doctors to see up to five times deeper than at present over
an area of up to one or two square inches.
Although the technique has not yet been tested on human skin, the engineers
believe it could have applications in diagnosis; helping to reveal the
extent of skin cancer, for example, and in treatment, by allowing a laser
beam to be targeted on underlying tissue.
By injecting various substances, the team made small areas of rat or hamster
skin nearly transparent for 20 minutes or more. Prof Ashley Welch, the lead
investigator, said: "We could see a blood vessel which had not been
visible." Light does not usually penetrate skin because it is scattered,
like a torch beam in fog.
Just as each water droplet in the fog scatters light, so small components of
tissue also scatter light. To overcome this, his team used glycerol, a
hygroscopic alcohol which pulls water out of tissue. The team has yet to
look into the toxicity of the technique, which Prof Welch admitted was "an
important question".
>
This archive was generated by hypermail 2b29 : Mon Oct 02 2000 - 17:36:26 MDT