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From: rowe@pender.ee.upenn.edu (Mickey Rowe)
Newsgroups: sci.bio
Subject: Re: Surviving Electrocution
Message-ID: <41087@netnews.upenn.edu>
Date: 13 Apr 91 15:15:03 GMT
References: <1991Apr12.212721.519@husc3.harvard.edu>
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In article <1991Apr12.212721.519@husc3.harvard.edu> mason3@husc9.harvard.edu (Richard Mason) writes:
>I have two questions regarding electrocution:
>
>1) Would it be possible to send a large electrical current through a human
>   being or other animal and have them survive without permanent damage?

Do your rules allow for subsequent defibrillation?  I read an article
in _Medical Instrumentation_ back in '86 or '87 that spoke about
electrocution (I could dig it up, but it would take a lot of work).
It seems that the critical factor is timing more than amount of
current.  The problem is that if the current density in the heart is
high during repolarization of the ventricles (the t-wave of an EKG)
the heart will be put into fibrillation, and death is essentially
brought on like a major heart attack.  If the patient is defibrillated
(e.g. another shock applied so that the whole heart is made refractory
at the same time) then the person can be brought back with few ill
effects. 

>2) How non-uniform is the resistivity of animal (human) tissue?  Is there
>   any way to make the resistivity more uniform, or otherwise to ensure
>   that the current in part (1) is roughly uniform throughout the body?

It's going to be pretty non-uniform, because blood vessels and other
structures will provide guides for current flow...  Also it will be
time dependent, since the sweat on your skin, the amount of
constriction of individual arterioles and venules etc. will vary
enough to give significantly different values at different times.

As for the second part of this question, I'd guess that you couldn't
appreciably homogenize (or even isotropize--hey that's a neat word :)
the resistivity while the organism was still alive.  But that's just a
guess. 

>
>If anybody answers (especially with positives), I'll tell you why I want
>to know.  (Perhaps you can guess.)

I don't think I want to know :)

>-- 
>"These things are pure science fiction! And yet they are all true."
>                                              -M.O. Rabin
>===================================================================
>Richard Mason | mason3@husc9.harvard.edu | All opinions are my own.

Mickey Rowe      (rowe@pender.ee.upenn.edu)