X-Message-Number: 4480
Newsgroups: sci.cryonics
Date: Tue, 6 Jun 1995 19:25:59 +0200 (MET DST)
From: Eugen Leitl <>
Subject: neuropatients&uploaders
Message-Id: <>

0. Motivation

Uploading pursues distinctly different goals than the cryonics
mainstream. Hence, it will also require somewhat different
procedures. This is an informal outline of some of them.

1. Death and Euthanasia

This is primary a legal and medical ethics question. If we
extrapolate current relaxation trends ("anything goes") into the
future, there seems to be some reason for cautious optimism.
Adopting citizenship of legally pioneering states shortly before
imminent death may appear as a sensible idea.

Nonlegal practices should be avoided at any costs: demand for
trust and transparency of a cryonics corp will require easy
inspection of financial and storage conditions, which is
impossible for black clinics. Since successful legal action can
cause instant demise of affected cryonic corp and its entire
patient bank, this requires very careful legal navigation.

A decephalized body can be released almost immediately to
relatives for rites/burial with relatively small, easily
camouflageable superficial damage, a possibly important point
for those wishing to conform with relative's expectations.

In future euthanasia will be certainly allowed for persons
laboring under an intreatable illness in most countries of
western hemisphere. Even suicide may become legally allowed with
(some) time. Of course this will make life insurance financing
impossible, thus requiring alternative financing schemes.

Induced cardiac arrest (e.g. IV KCl-triggered) of (precooled)
anaesthesized (freon- or dinitrogenoxide-type gas inhalation
anaesthesy) patients seems to be a good model for painless

2. Uploader/Neuropatients

Reduced tissue bulk size to be processed as required for
neuropatients has very definite advantages:

The total bulk to process, transport and store is much smaller.
Thermal energy content of tissue volume to process is smaller.
Tissue is monotyped/isotropic. Speed of cryoagent diffusion is
excellent, less agent is necessary. The necessary cryoprocessing
machinery can be very compact, cheap and easy to transport (a
major cost factor especially for oversea actions). Cryoteam size
can dwindle to 2-3 persons.

Neuropatient transport is trivial. Legal ("tissue sample" vs
"corpse") as well as freight volume pose basically no problems.
Dry ice exhalation or lN_2 boiloff may cause difficulties during
air transport (cabin air contamination with nonbreathables),
though. A Peltier cool box may be better here.

Brain's surface/volume ratio is much better, allows much higher
initial (process bottleneck) cooling rates.

The brain has excellent capillary infrastructure, allowing
thermic descent and perfusion in one go.

Reduced storage volume is another big plus. At the same dewar
size orders of magnitude more patients can be stored, allowing
much lower per capita ;) cooling medium cost.

3. Decapitation and Cryoperfusion Programme

Warm ischemia period should be minimized. But, since we are
going for information death time window here, constraints are
not so very.

After instant decapitation (hydraulic/electric guillotine?),
cryoperfusion outlets should be immediately plugged into the
main neck arteria(s). Diameter-adjustable no-fuss custom clamp
outlets will be required. All blood must be flushed out
instantly. Anticoagulant and initial flush solution
composition/temperature must be optimized. Plastic wrapped
(multiple layers) head can now be submerged into an external
ice/water bath to assist internal cooling.

A cheap peristaltic pump (redundant, of course) may suffice
here. After all blood has been flushed out, closed circuit flux
can be established. The oxygenated perfusion fluid can be the
standard one as for organ preservation, though alternative
receptures should be investigated. A steep temperature descent
programme, using RT/0 deg C gradient mix machine is then
initiated. After arriving at 0 deg C, the cerebrum is removed
from the skull and reconnected to perfusion jacks. After 5-10
min, 0 deg C temperature should be achieved.

Now cerebrum is suspended in transit flow container for
oxygenated cryofluid (plus glucose) and a cryofluid gradient
programme is begun. Through low-toxic, pure glycerol diffusion
rate is suboptimal. Dimethylsulfoxide (DMSO, Me_2SO_2, m.p. 18.4
deg C) is a great transmembrane shuttle and breaks water
structure even better than propantriol at low tissue toxicity.
As lots of phospholipid membranes have to be permeated, DMSO is
orders of magnitude better agent than propantriol.

A mix of both should be probably optimal, I think.

After thorough permeation has been achieved, (vacuum)
deoxygenated (helium/argon flushed) fluid, now without other
additives is used for perfusion. Since radical chain reactions
work best at deep temperature, very low oxygene residual content
must be achieved. Glass matrix will prevent the worst, yet...

Now temperature descent gradient to liquid N_2 temperature is
initiated. Cracking should be minimalized, yet is not very
critical, since we are going to cut the tissue up in the end all
the same.

Entire procedure and personal data are stored in the corp
database, printouts on acid free paper go into archive. The same
data, recorded on a sturdy medium (photolitho metal foil or
photo-glass microfiche) in human readable form should be stored
with each patient.

Additionally, digitized detailed picture material describing
body geometry (high resolution color snapshots from different
sizes, microphotography to document texture/colouring etc. en
detail, skin/hair/other tissue specimens, voice samples, etc.),
MRI/squid imaging data, and personal data should also go into
the vault. Redundant storage medium should be a WORM, with
periodical checks/rewrites to counteract medium deterioration.

As much context as possible should be preserved, to reduce
future sensory overload shock after reanimation.

4. Tissue Storage

Each cerebrum should be sealed (in a vitreous cryofluid block?)
in oxygen-free microenvironment together with basic
documentation in a carrier with both machine-readable (e.g. bar
code (rime is transparent for IR) or induction loop sender
(won't work, if too cold)) and human-readable label. Carriers
should fit into columnar metacarriers accessable from dewar top.
Each dewar should have a machine/human readable list linking
position index with patient ID to facilitate retrieval.

Dewar volume should be big to enhance volume/surface ratio.
Though spheres are best, cylindrical shape does greatly
facilitate de/loading. Since for good dewars black body
radiation is the major energy leak, external cooling of outer
dewar layers (e.g. to -20..-70 deg C, the lower the better)
using standard (molbio lab fridges) refrigerator technology
could significantly reduce nitrogen boiloff. Sufficient -70 deg
C external refrigerator capacities should exist for emergency.

Though industrial lN_2 is much cheaper, a local diesel-driven
air rectifier should be considered as failsafe cryomedium backup
source. Photovoltaics and/or geothermal gradients are better
than diesel, though. Conservative estimates seem to indicate a
monocrystalline Si solar panel to usable for at least 50 years.
Particularly, air/subterraneous water stream temperature delta
could be used for direct cooling (Carnot cycle machine). Though
having bad yields, Peltier element arrays should be discussed as
1stage cooling/energy source.

5. Tissue Fragmentation

Vitrified cerebrum bulk must be cut (diamond or glass knife
microtome) into cubic tissue blocks, edge < 1mm. Edge cut
artefacts have to be removed with DSP methods. Both block x,y,z
index and orientation must be recorded, e.g. on the block
carrier. Such tiny specimens can be temporarily thawed to be
subject to immunostaining or other contrast-enhancing
procedures. Each block can be scanned independantly

6. Scan/Processing

6.1 Nondestructive Scan

Yet-to-come xRay fresnel/holographic diffraction lattice optics
utilizing monochrome synchrotrone radiation might do. But: the
contrast ratio is very poor, immunostaining with metal-labeled
antibodies may be needed. Energy deposit by xRay absorbance will
cause cumulative rad damage, virtually cooking the sample. Gamma
cannot be focused at all, apart from requiring nuke-pumped
lasers for sufficient intensities. Since brain is no crystal,
there is no diffraction picture to analyze. Tomography might be
possible, yet resolution is not so very great.

Neutron beam tomography is another alternative. Suffers from the
same problems.

Transmission EM has sufficient resolution, but requires very
thin samples with very elaborate preparation. Rad damage here

This is about all. There are not any nondestructive scan methods
I can think of. Any ideas?

6.2 Destructive Scan

My long-time favourite has been UV-abrasion of immunostained
vitrified tissue coupled with sensitive mass spectrometry.

A weak pulsed excimer laser output, channeled through a quartz
(or something with wider UV window) optofiber with 50-100 nm tip
(no optics, since we cannot focus spot beyond wavelength)
shining upon a point of cooled vitrified probe in vacuum will
instantly dissotiate bonds in a layer few molecules thick,
causing ionized debris expand isotropically. A sensitive MS can
suck off this cloud, analyzing debris. Nanoantibodes
(essentially, a tiny antibody fragment having only one
antigen-bonding site) can be easily (nonradiocative) isotope
labeled, offering rich CHNOS (c12/c13, h1/h2, etc.) isotope
fingerprints. Engineered microorganisms, grown in isotope
labeled media are simple (but not cheap) sources of such

Alternatively, abrasion could also be done with an electrone
beam writer. Vertical resolution goes down, though.

Resolution is not too great, but a wealth of detail can be read
since isotope labeling allows plethora of label flags.

Abrasive atomic force microscope (AFM) scan is much better It
needs no vacuum nor any sample preparation, reads and abrades
with the same medium (needle) at up to video data stream rates
and has excellent resolution (single atomes/molecules). But it
produces only the shape information ("form follows function").
The device is very cheap (<$500-$1000), if mass produced. If
scanned tissue is not too cold (ice will scratch metal, if
sufficiently cooled), needle tip will serve almost indefinitely.

7. Storage

Let us assume 10 G neurons with the average synapse branching
factor of 10 k (though in single cases convergence factors of up
to 100 k are known). Hence a 34 bit neuron ID is sufficient.
Each neuron body state dynamic range (firing probability or mean
firing frequency within time window) will be represented by an
integer of 0..255 (8 bit), each synapse weight 8 bit and 8 bit
for signal delay. Hence, each neuron will need 8(+8)+(34+8+8)*10
000 = 0.5 MBits for an adequate representation. In toto 10 G *
0.5 Mbits=5*10^15 or 5 PBits (peta bits). Assuming off-shelf 10
GBytes (80 Gbits) DAT cartridge, we'd need roughly 64k
cartridges. Taking soon-to-arrive 1 TByte (8 TBit) cartidges,
about 600 of these.

Notice that this is the maximum amount. This is uncompressed
data: utilizing representation redundancies (e.g. relative
instead of absolute addressing) at least one order of magnitude
compression ratio can be achieved. Moreover, 6 bits instead of 8
is probably the dynamic range. Delay is probably unnecessary,
since message packet routing artefacts introduce inherent
delays, proportional to original physical distance.

So 80 1TByte- or 8000 standard DAT cartridges is probably the
number in question. Notice that was lossless compression.
Higher-order codings, sufficiently elaborate to accurately
mimick state-space strange attractor kinetics could probably
reduce the amount to a 8-80 DAT cartridges. But this is pure
blueskyeing. I have no data on cerebral system collapsibility

9. Upload

A. Modus operandi

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