X-Message-Number: 9526
From: Ettinger <>
Date: Mon, 20 Apr 1998 11:20:03 EDT
Subject: Cryostats Again

CRYOSTATS AGAIN

It's no big deal, but I'll comment briefly on Paul Wakfer's Cryonet #9523.

By "MVE type" I just mean the type that uses very high vacuum with multiple
radiation barriers, the so-called "super insulation." 

Why does "almost everyone" use them? Because, for small volumes, they offer
the best insulation and occupy the least space. But in addition to any
refurbishing problems, they are relatively fragile. We get delivery in such
units, and often see hot spots resulting from little dents. If well protected,
of course, this is not a serious problem. But repairs do require return to the
factory, I believe. If ours should ever need repair, we can do it in-house.

We could use MVE type if we chose. We don't choose. We emphasize reliability,
ruggedness, and in-house self-reliance.

For intermediate size cryostats, the industry standard, I believe, is still
perlite with moderate vacuum. This is what we use (with containers of
fiberglass). For very large units, the industry standard is powder or foam
insulation with no vacuum. When patient population becomes large, the MVE type
is unlikely to continue in use. 

As to the "cold room" technology being developed at 21CM, my impression from
published information was that it was indeed intended to be used in patient
preparation as well as storage. The idea was to get very fast perfusion and
cooldown, as a way to overcome remaining problems with vitrification. Maybe
I'm wrong about this.

And finally, no, I don't "know" what other organizations are "contemplating,"
but I know what they have published, and base my impression on that. CI has
made public mention of several projects that others have not. 

Robert Ettinger
Cryonics Institute
Immortalist Society
http://www.cryonics.org

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