Dr. Wowk wrote: “Present cryopreservation technology even under perfect conditions causes biological effects such as toxicity and fracturing that are far more damaging than the types of problems you’ve expressed concern about. Even if the hypothermic phase of cryonics were done perfectly, with completely reversibility, what happens during the cryothermic phase is so extreme as to make the damage from poorly-executed blood washout insignificant by comparison.”
CATASTROPHIC? EXTREME DAMAGE? I am curious why Alcor insists on bringing the temperature during cryopreservation down to −196 degrees C (liquid nitrogen temperature) when fractures are occurring below −130 degrees C. Glass transition is already completed at −90 to −130 degrees. It seems that going below −130 degrees is not only useless for purpose of long term preservation, but it also ensures apparently catastrophic and irreversible damages, as you admitted. Granted it might take more effort and it might be a little more expensive to maintain the temperature in the −90 to −130 degrees, but the catastrophic micro-fracture damage does not occur in any meaningful degree. I do not believe Alcor ever provided satisfactory answer to this.
I’m doing a text search, and I can’t find where I used the word “catastrophic.” In any case, the damage done by present cryopreservation techniques is extreme by conventional medical standards (e.g. decapitation). The real question is the significance of the damage in the context of preservation of brain information encoding memory and personal identity, which is what cryonics seeks to preserve.
For decades Alcor has sought to be conservative and perform the first hypothermic stages of cryonics to a standard closer to that of medicine rather than mortuary science to make the early stages of cryonics closer to reversible. This has drawn criticism from two opposite directions. Bob Ettinger has criticized this approach because it is expensive, and nanotechnology is likely “necessary and sufficient” for revival of cryonics patients even without aggressive care immediately following cardiac arrest. More recently, Melody Maxim has criticized Alcor and SA because they fail to consistently deliver care following cardiac arrest to medical standards (even though there are no recognized medical standards for cardiopulmonary support, medication, cannulation and perfusion of legally dead bodies in an ice bath destined for cryopreservation other than the standards established by the cryonicists she derides.) It appears that the only alternatives that will please all critics are to either not do standby/stabilization at all, or to do it to a much higher and even more expensive standard than now being achieved.
With respect to fracturing, fracturing in cryopreservation is explained here
The problem is that there is still no known protocol for reliably cooling a large vitrified organ to temperatures ten or twenty degrees below the glass transition temperature without fracturing. More research needs to be done. Notwithstanding, there has been great progress in the past decade in developing engineering solutions to safe intermediate temperature storage. I gave a talk on this progress here
Alcor has experimentally used three different systems for intermediate temperature storage in the past decade. Some of these systems were grossly misrepresented by Larry Johnson as causing fracturing, rather than mitigating it (showing once again how difficult it is to make any progress in cryonics without the effort being misrepresented and used against you). In December 2008, the system described in the talk above was installed at Alcor. I’ll be writing an article about it next year.
These systems reduce fractures compared to liquid nitrogen storage, but don’t seem to eliminate them. Eliminating fracturing will require tedious research on cooling protocols. The research is tedious because it will likely require months, if not years, of holding at temperatures warmer than the final storage temperature to relieve thermal stress.
Finally, it is not “a little more expensive” to do storage at temperatures above liquid nitrogen temperature. It is about three times more expensive. It also took many years and six figures of research dollars to figure out it how to do it with a reliability more similar to that of liquid nitrogen rather than a mechanical freezer.
Dr. Wowk wrote: “Present cryopreservation technology even under perfect conditions causes biological effects such as toxicity and fracturing that are far more damaging than the types of problems you’ve expressed concern about. Even if the hypothermic phase of cryonics were done perfectly, with completely reversibility, what happens during the cryothermic phase is so extreme as to make the damage from poorly-executed blood washout insignificant by comparison.”
CATASTROPHIC? EXTREME DAMAGE? I am curious why Alcor insists on bringing the temperature during cryopreservation down to −196 degrees C (liquid nitrogen temperature) when fractures are occurring below −130 degrees C. Glass transition is already completed at −90 to −130 degrees. It seems that going below −130 degrees is not only useless for purpose of long term preservation, but it also ensures apparently catastrophic and irreversible damages, as you admitted. Granted it might take more effort and it might be a little more expensive to maintain the temperature in the −90 to −130 degrees, but the catastrophic micro-fracture damage does not occur in any meaningful degree. I do not believe Alcor ever provided satisfactory answer to this.
I’m doing a text search, and I can’t find where I used the word “catastrophic.” In any case, the damage done by present cryopreservation techniques is extreme by conventional medical standards (e.g. decapitation). The real question is the significance of the damage in the context of preservation of brain information encoding memory and personal identity, which is what cryonics seeks to preserve.
For decades Alcor has sought to be conservative and perform the first hypothermic stages of cryonics to a standard closer to that of medicine rather than mortuary science to make the early stages of cryonics closer to reversible. This has drawn criticism from two opposite directions. Bob Ettinger has criticized this approach because it is expensive, and nanotechnology is likely “necessary and sufficient” for revival of cryonics patients even without aggressive care immediately following cardiac arrest. More recently, Melody Maxim has criticized Alcor and SA because they fail to consistently deliver care following cardiac arrest to medical standards (even though there are no recognized medical standards for cardiopulmonary support, medication, cannulation and perfusion of legally dead bodies in an ice bath destined for cryopreservation other than the standards established by the cryonicists she derides.) It appears that the only alternatives that will please all critics are to either not do standby/stabilization at all, or to do it to a much higher and even more expensive standard than now being achieved.
With respect to fracturing, fracturing in cryopreservation is explained here
http://www.alcor.org/Library/html/CryopreservationAndFracturing.html
The problem is that there is still no known protocol for reliably cooling a large vitrified organ to temperatures ten or twenty degrees below the glass transition temperature without fracturing. More research needs to be done. Notwithstanding, there has been great progress in the past decade in developing engineering solutions to safe intermediate temperature storage. I gave a talk on this progress here
http://www.suspendedinc.com/conference/SA_conference.pdf
Alcor has experimentally used three different systems for intermediate temperature storage in the past decade. Some of these systems were grossly misrepresented by Larry Johnson as causing fracturing, rather than mitigating it (showing once again how difficult it is to make any progress in cryonics without the effort being misrepresented and used against you). In December 2008, the system described in the talk above was installed at Alcor. I’ll be writing an article about it next year.
These systems reduce fractures compared to liquid nitrogen storage, but don’t seem to eliminate them. Eliminating fracturing will require tedious research on cooling protocols. The research is tedious because it will likely require months, if not years, of holding at temperatures warmer than the final storage temperature to relieve thermal stress.
Finally, it is not “a little more expensive” to do storage at temperatures above liquid nitrogen temperature. It is about three times more expensive. It also took many years and six figures of research dollars to figure out it how to do it with a reliability more similar to that of liquid nitrogen rather than a mechanical freezer.