Wednesday, September 4, 2013

Above Zero Cryo Stasis

I recently posted this entry on my idea for cryo surgery but I have been kicking around another more generally applicable idea for long term hibernation/stasis for quite some time, but have never written it down.

I would love to see research/investigation into hibernation stasis at temperatures slightly above freezing. A long time staple of science fiction - from the Alien franchise, through Demolition Man, Stargate, Firefly and many other classics of science fiction including let us not forget, Star Wars, Star Trek, and Buck Rogers, as well as a recurring trope of video games from Portal to Fallout, I think it's actually a technology we could develop in reality, in the here and now.


The problem with freezing a complex organism like a human is that when ice crystals form, their structure destroys the cellular workings of the body.


This makes freezing a person to put them into long term stasis kind of problematic - as they will wake up dead when melted.

But - other than killing the subject, freezing a person would be a great way to get people to the Moon, Mars, other plantes/moons in our solar system and even to other stars. It would also be a good way for people to 'quickly' (subjectively) travel to the future. But it would also save taxpayer money. Beyond all the space travel aspects, think of the Military - when not in use, tax payers have to maintain the personnel in the military, and they must constantly train to avoid skill fade, which consumes additional costly resources, etc. If we could induct classes from boot camp, furnish them with advanced skills training, and then put them in cryo-stasis, they could sit there on ice until a situation requiring their skills were needed. When reanimated they would be as prepared and capable as graduation day. We would be able to have instant-on-demand military might, without paying for standing armies when not in use. Meanwhile, the soldier thus stored could be earning half or quarter pay for the entire time, and when they get discharged, be as young and healthy as they day they graduated boot camp, but significantly more well off financially.

So - how do we get there?

I think the following approach would likely bear fruit.

Rather than trying to freeze a person solid, drop their body temperature to less than a degree above freezing, and let no part of their body get colder than that. This would require very precise temperature sensors both in the body (needle thin thermocouples inserted into the major organs and muscle groups) as well as in the cooling mechanisms to ensure no transient thermal dips.


A non-toxic cocktail of substances could be introduced into the body to increase the temperature ice crystals form - such as glycerine, mixed with probably some broad spectrum anti-biotics to further suppress bacterial growth.

The subject would be intubated and would be put on bypass at extremely low speeds, blood would continue to flow, and oxygen would be in the lungs, but respiration and cardiac functions would be completely stopped. Almost all metabolic activity would cease, but there would be fuel/oxygen in the system for cellular consumption. This would help in several ways. First, any minimal metabolic activity would be sustained, and Second, when the subject is awoken, their will be fuel and oxygen in the system for cellular activity to resume.

Consider the many examples of people falling into ice cold bodies of water, and being recovered hours later, who make a full recovery. Some of those victims make partial recoveries, suffering brain damage, but others are fully 100% recovered with no deleterious effects at all. I suspect the difference is how quickly the brain cools once respiration and cardiac functions cease, once fuel and oxygen stops being renewed in the cerebral tissues. I suspect that a victim of falling into freezing water who's brain rapidly cools to sub 40 degrees, before oxygen depravation starts to work its ravaging way thru the neural tissue, are the ones that make the full recovery.

It is also possible that some of the victims with lingering negative effects got too cold, and perhaps ice crystals started to form in their brain or other organs, those crystals ripping their cellular walls to ribbons.

We know that a mammal's heart beat and respiration will stop at temperatures much higher than freezing. And we know that refrigeration keeps food (which for some people includes the flesh of dead animals) fresh for longer than leaving the food at room temperature. If we can cool a person to just above freezing, rapidly and while keeping oxygenated, nutrient filled blood flowing, and if we can return them to normal body temperature quickly, without ever interrupting the flow of blood and nutrients, there should be no reason a person kept in such a state could not be maintained for extended periods of time.

To quiesce a subject, placing them into stasis, one would likely require several days of preparation. First, the subject would be subjected to a regime similar to the preparation for a colonoscopy, they would have their GI and bowels completely cleaned out, and would spend 24 hours after being purged consuming nothing but water. They'd also be put on a broad spectrum anti-biotic. The subject would be placed in the stasis chamber, connected to an IV which would introduce a solution comprised of a soporific, anti-biotic, and a saline solution, possibly laced with other non-toxic anti-freeze molecules, such as glycerine. Once unconscious, the subject would be intubated, and would be partially submerged in a thermally conductive hydrating gel. The body temperature would be reduced until cardiac and respiratory functions ceased, at which point the subject would be connected to a low velocity / low pressure bypass system to circulate the blood through the subject's body. At this point, needle thin thermocouple temperature sensing probes would be inserted into the major muscle groups, and thoracic cavity, as well as a probe deep into the sinus cavity. These thermocouples would be used to precisely control the temperature of the chamber and the subject. A ventilator would be connected to the intubation tube, and the ventilator, bypass system and IV would serve the subject for the duration of their stasis session.

Measures would need to be taken to control bacterial/viral proliferation, the stasis systems would need to be designed to offer little vibration, the low pressure, low velocity bypass pumps would need to be gentle enough not to damage any red blood cells, the lungs would need to be kept on ventilators, and the whole body would need to be kept in a hydrating thermally conductive gel so that there was no 'freezer burn' dehydration of tissues.

Upon reanimation, the subject would need to be warmed back up to normal operational temperature, while being kept on bypass and ventilators, and when warm enough, the heart would need to be restarted with a defibrillator.

Once the subject's heart was beating and lungs were functioning on their own, the bypass and intubation systems could be removed, and shortly thereafter, the subject could be allowed to wake up, where after a brief recovery they would be able to resume normal physical and mental activities.

While the subject would be on bypass and ventilated and while nutrients would be available via the IV, the total calories consumed, total O2 consumed and total waste produced during this period of stasis should be negligible, which would make this process ideally suited to long term space travel where resources are so costly, further, such a chamber would be easily shielded from radiation.

But - this process would also be useful where resources were not at issue but instead, time was the villain, time sapping the skills and preparedness of soldiers, or time sapping the youth and vitality of key citizens who's skills/knowledge/experience would be needed in the future, or simply time that remains between the current time and a future time where newer technological capabilities await. Imagine, for example, some of the luminaries of our age - Richard Dawkins, Neil DeGrasse Tyson, Lawrence Krauss, Lisa Randall, Michio Kaku, Brian Greene, Carolyn Porco, etc, etc - imagine being able to allow them to hibernate in stasis until such time as senescence could be staved off indefinitely, thereby allowing them to continue to contribute to our society for the life of our civilization?

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Tuesday, September 3, 2013

Robot Surgeons and Cryo Surgery




I was thinking about medicine, and medical technology. Specifically about surgical procedures and what I know of the state of the art.


For quite a while it has baffled me why we perform surgery on patients while they are warm, have hearts beating and lungs inflating. There's all that movement, and of course, the flowing blood, which can leak out and make a mess, etc. Further, it seems a lot of surgical procedures are under a variety of time constraints and I have heard of marathon surgical sessions where a doctor (or tag team of doctors) have performed surgery for many hours consecutively without breaks. This seems like a recipe for disaster.




I would have thought it would be better to chill a subject down to 35 degrees F, just above freezing, that way a surgeon could perform delicate surgery without the heart beating, lungs inflating or blood flowing. Additionally, the subject could be kept at that temperature, stable and without metabolic functions occurring for quite some time, most likely days (*may require some non-toxic preservative, possibly just a broad spectrum anti-biotic). This would allow surgery to be performed over time, unhurried. It would be measured and methodical. Additionally, while the tissues would not be frozen solid at 35 degrees F, they would be firmer, allowing for more precise manipulation.

So - why isn't that the normal practice today? It occurred to me that the issue might be that a human surgeon would not be able to perform delicate.. or actually even gross surgery at those temperatures. The human surgeon's fingers would lose fine motor control, there would be risk of chills and shivers causing undesired muscle contractions, and none of those effects would be tolerable in any surgery.


Gloves would not be an option because if they were thick enough to allow the human surgeon to operate without degradation of dexterity and risk of shivers, then they would be too thick for any delicate movements. If the gloves were ultra thin but somehow heated, then the heat would risk the integrity of the patient's tissues which have to be maintained at the 35 degree F temperature.

So - while attractive in theory for a variety of reasons, Cryo surgery would be impractical if the procedure was being performed by one or more human surgeons.

NOW ALL THAT CAN CHANGE

Robotic surgery has become a viable and quite successful alternative to surgical procedures performed directly by a human. Robotic surgery has allowed for procedures that a human cannot do manually due to the requirement for exactingly precise and fine movements which are not possible with a human hand and a human eye but which can be done by a human directing a robotic limb and using enhanced vision from electronic ccd cameras.




If Robotic surgery allows for procedures which a human cannot perform on their own, then a Robot should be able to perform any procedure that a human can as well. And a robot can perform at any temperature range with no change to performance capabilities.

If we combine the two concepts above -

chilling the surgical subject down to 35 (or 34 or 33, anything just north of 32) degrees F, and then use Robotic surgical systems to perform the surgery, then all procedures should see an increase in success rates, some minor procedures may not see much of a change as they are close to 100% successful now, and the cost/complexity of the cryonic process may exceed the benefit but for others the improvement should fully warrant the extra
effort.

I would further speculate that procedures performed in this manner would result in reduced recovery time and better post operative response. Inflammation should be reduced, sutures should be more precisely implemented, etc.


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