[Robotgroup] Cold laser

[Ed Xavier Gonzalez]

I would STRONGLY caution anyone considering purchasing ANY laser that 
outputs more than a few milliwatts of coherent energy to be EXTREMELY 
careful!  These things are DAMN dangerous to the untrained or 
uninitiated.  Particularly any laser that can output wavelengths that 
are not visible or 'eyesafe' at even long distances.

I would be particularly upset if someone that didn't know what they 
were doing bought the laser just for fun, because even low power 
medical lasers can do a lot of damage.

As far as a 'cold' laser, if it operates in the UV or deep UV, it can 
do a tremendous amount of damage, because it doesn't generate the 
heat that skin normally reacts to so the person attached to it can 
reel away screaming in pain.

That's why ophthalmologists use excimer lasers for doing corneal 
ablative reconstruction, aka, permanent vision correction.  Since the 
excimer lasers they use operate in the UV range, there is no heat 
produced during the excitation of the top few thousandths of an inch 
of corneal tissue.  It would still hurt like Holy Hell, which is why 
they numb the eyeball during the operation.

Since the wavelength is so short, no significant damage occurs to the 
soft tissue around or deep inside where the laser strikes the 
surface, with the only result being the liberation of some skin cells 
at a very minuscule level.

Consider looking straight into the resonant cavity of a machine 
putting out a few dozen watts at UV while the thing is running.  It's 
got to be the only case where looking right into a running laser is 
approved by the medical community.

Still darn dangerous if not done correctly.  I've heard more than my 
share of horror stories where people that didn't know a laser was 
running in the UV or far-IR range got zapped and lost their vision 
due to inadequate labelling of the entry door.  Specular reflections 
can change the beampath and nobody truly knows where the final spot 
lands until somebody starts screaming or the table starts on fire.

If anyone finds out about the sale on Craigslist, I'd very much like 
to know.  If the price is right, I might go into a different line of 
laser work and do laser nut shaving.  Vern has already asked for this 
once, and has inquired about my doing a box of 1/4-20 stainless steel 
standard thread nuts for potential use in a future project.

I'm serious about the interest in the laser, but have reservations 
about doing any machining work on anyone's nuts, since the quantities 
needed to be cost effective may not make it worthwhile.

-------------------------------------------

At 12:33 AM 4/11/07, you wrote:
>The reason I asked is that I know a physical therapist who is
>retiring. She is going to be listing a lot of stuff on Craig's List,
>including a cold laser. So I was really wondering if it might be
>useful for something besides deep tissue stimulation.
>
>Thanks,
>Bob Comer
>
>-- Def Egge <robodigest at innervate.com> wrote:
>The American Cancer Society seems skeptical about cold laser therapy
>but discusses some claimed benefits.
>
>http://www.cancer.org/docroot/ETO/content/ETO_5_3X_Cold_Laser_Therapy.
>asp
>
>There is a veritable ton of information out there but caveat emptor.
>
>
>All the best....
>
>Mike
>
>
>
>
>At 23:44  2007-04-10, you wrote:
> >Sounds a little suspicious to me.
> >http://en.wikipedia.org/wiki/Laser_therapy
> >http://en.wikipedia.org/wiki/Cold_laser_therapy
> >
> >Personally, I don't think I buy into the idea that low levels of
>laser light
> >is going to provide much clinical benefit for an internal
>physiological
> >condition.  The low levels of light just does not penetrate that far
>and our
> >cells are just not that photosensitive (with the exception of our
>eyes) such
> >that they react to light.  Come to think of it, the melanin in our
>skin that
> >is photoreactive over time is there to block light.
> >
> >I just don't see a plausible mechanism where this would do anything
> >beneficial over a heating pad.  Perhaps one of our medically trained
>members
> >would have some insight as to how this would work.
> >
> >- Eric
> >
> >
> >
> >
> >On 4/10/07, thecomers at juno.com <thecomers at juno.com> wrote:
> > >
> > > Has anyone heard of an interesting use for a cold laser (as in
>cold
> > > laser therapy,or photobiomodulation)?
> > >
> > > Thanks,
> > > Bob Comer
> > >
> > >
> > >
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> > >
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<The right to Free Speech does not diminish the value of remaining silent>

Ed Xavier Gonzalez
Oak Hill Laser
ohlaser at swbell.net
(512) 288-5243