Re: rf burns

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Shaun Epp by way of Terry Fritz <twftesla-at-qwest-dot-net>" <scepp-at-mts-dot-net>

The cautery that you talk about is still used regularly in surgery.
Electrosurgery use up to 300 watts of RF at 500KHz in the several kv range
applied to the body.  The electrode is a flattened wire tip in a plastic
handle and the RF energy is returned via a return electrode, usually a flat
plate electrode that sticks itself onto the patients leg.  The surface area
of the flat plate protects the patient from burns at the return electrode.
Burns are caused by the amount of energy per unit area and causes heating at
that point, this is why the small tip electrode is the business end of the
ESU (electrosurgical unit).  As you said the energy not only cuts, but is
also fuses the bleeders for a cleaner and safer incision.  The electrode tip
touches the flesh or sometime is held just about it depending on the use for
cutting or fusing / burning tissue, further into the body the energy spreads
out and travels along all parts of the body until is returns by the return
electrode.  It flows by volume conduction through the body, through muscles,
tissue, organs, fluids.....

Cautery is actually using a hot wire to cut with but, it is often confused
with electrsurgery.

3MHz models are used for eye surgery at lower powers.  The ESU's sometimes
use forceps, each side of the ~~tweezers is connect to the generator so the
the RF passes through the tissue from one side of the focept to the other
side.

I'm not sure about bone or bone marrow though, but a friend of mine was
zapped by RF and he said it went down to the bone too.

I don't use these machines but I test and sometime have repaired them.

Shaun Epp

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, February 23, 2002 9:50 PM
Subject: Re: rf burns


> Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<davep-at-quik-dot-com>
>
>
> > Mark: flame burns are on the surface then go in. Rf burns are from bone
out.
> > They are deep tissue burns. I had one in my finger that burned a small
black
> > trail through the marrow of the bone. That was real long healing, it
drained
> > over a mounth and took longer to heal.
>
> I suspect it varies with the kind of RF burns: freq, power,
> and how applied.  An RF 'arc', if it flashes thru to bone,
> might well act as described.  A lower power one, or one applied
> by an induction coil, might stay more surface bound.
>
> > > From: "Tesla list" <tesla-at-pupman-dot-com>
> > > Date: Fri, 22 Feb 2002 08:14:35 -0700
> >
> > > Subject: rf burns
>
> > > Hi Everyone,
>
> > > Just wondering why rf burns take so long to heal compared to normal
burns.
> > > Over the years I've had a few minor rf burns off my sstc and they
> > > definitely do take a while to heal.
>
> > > I think I remember reading somewhere a long time ago that rf burns
take a
> > > long time to heal because the rf seals off the entire burn (including
under
> > > the skin) so that blood or whatever cannot get to the burn to heal it.
A
> > > normal burn is only on the top of the skin so that blood can get
underneath
> > > to start the healing process.
>
> > > Is the above true? I've tried doing a search on yahoo for rf burns but
I
> > > have not come up with anything that talks about them in detail.
>
> I'm no medical expert, i believe it is correct.  There used to
> be use of 'rf cauterization', to seal tissue during, or after
> surgery:  rf applied from an RF source to the tissue.  I'm
> REAL fuzzy on details, some google work on 'cauterize
> cauterization' etc would be instructive...
>
> I THINK this was vi an RF arc from two closely spaced
> electrodes, which would not tend to 'go to the bone'.
>
> best
> dwp
> best
> dwp
>