X-Message-Number: 3129 Subject: CRYONICS-Another use for Hyperbaric Chamber From: (Edgar W. Swank) Date: Tue, 13 Sep 94 09:13:41 PDT In Cryomsg 3056, made the constructive suggestion of using a hyperbaric chamber in research to improve our suspension techniques. I'd like to point out that this device could also be used as a hypo- baric (partial vacuum) chamber which would be useful in persuing a line of research I've called gaseous perfusion. A whole-body partial vacuum could be useful in getting water-based perfusate to vaporize, when it could then be "washed out" by helium or some other gas, which could then be used as heat transport to quickly & uniformly lower body cells temperature from ~0C to LN2. Conversely, body cells could be quickly & uniformly warmed by circulating He at ~0C and water vapor could be re-introduced under partial vacuum. Once all the He was washed out (to avoid emboli) pressure could be raised until water liquified and the perfusion process could (attempt) to be reversed. This approach attempts to apply to a whole body the technnique of fast freeze/thaw that is successful today in preserving sperm & embryos at LN2 temperatures. Even a future advanced nano-technology is going to find it much easier to revive an individual with a clear (He-filled) circulatory system; otherwise, they have to send in an army of nano ice-chippers, or (slowly and/or non-uniformly) raise body temp to above 0C, during which time more damage can occur. A hyperbaric/vacuum chamber for small mammal research would probably cost a lot less than the estimated $100K for a human-size version. This idea of gaseous perfusion was previously discussed in cryomsg's 1110-1112, 1168 1489 1494 -- (Edgar W. Swank) SPECTROX SYSTEMS +1.408.252.1005 Cupertino, Ca Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=3129