X-Message-Number: 5174 Date: Tue, 14 Nov 1995 10:45:36 -0800 (PST) From: Doug Skrecky <> Subject: vitrification proposal The following article may be reprinted in any cryonics oriented newsletter or magasine, whose editor wishes to do so: A VITRIFICATION PROPOSAL By Doug Skrecky Any attempt to vitrify with relatively low and non-toxic concentrations of cryoprotectant would require cooling rates in excess of that acheivable by immersing the entire body in any coolant. I would like to here outline a possible way out of this impass. The cardiovascular system has an internal area over 300 times that of the external bodily surfaces. Using the cardiovascular system as a heat exchanger would allow cooling rates considerably in excess of that achievable by whole body immersion. Coolant circulating through veins, arteries and capillaries would have to have a freezing point lower than the annealed glass transition of glycerol (-100 C) if glycerol is selected for the cryoprotectant, as well as a boiling point of at least 0 C. The coolant must also be nontoxic - which seemingly eliminates simple solvents such as ethanol (freezes -130 C) from consideration. At atmospheric pressure propane freezes at -187.7 C and boils at -42 C. At 5 atmospheres propane boils at +1.4 C and at 10 atmospheres at +.9 C. By keeping the body mildly pressurized perfusion with liquid propane at 0 C would be possible. After this has been accomplished propane cooled to -100 C or possibly even lower could be rapidly injected, thereby achieving very high cooling rates and hopefully vitrifying the body. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=5174