29 May '08 10:07>8 edits
This is my assessment on what may be the best way to cryogenically preserve a dead human in the hope that future technology would find a way to repair the damage to the body and bring the human back to life and why I don’t believe that the conventional method of cryogenic preservation of humans would work:
The usual procedure to cryogenically preserving a human body is to first cool the body then remove all the blood with the help of an ‘anticoagulant’ (which is a substance that prevents the blood clotting and, in this case, must be administered before the blood clots after death) and then, by pumping antifreeze solution through these blood vessels, replace the moisture in the body with an antifreeze solution designed to minimise the damage done through freezing and then, finally freeze the body down to liquid nitrogen temperature and keep it that temperature until if or when future technology can become so advanced that it can repair the damage and resurrect the person.
In the future, if technology ever becomes so advanced that it can perform the formidable task of repairing the microscopic damage done to the human brain as a direct result of freezing the brain then it must surely have become more than advanced enough to perform the comparatively much less formidable task of replacing every organ in the body with organs grown in a laboratory. Obviously, if future technology cannot repair the human brain then there is no hope of bringing the frozen person back because there would be no point in replacing the brain! Therefore, if we cryogenically freeze a human then there would be no point in doing so without the assumption that future technology not only would be able to repair the brain but would also be able to replace the whole body except the brain.
Therefore, it only makes sense to cryogenically preserve the brain of the person and not the body although, in practice, it would be easier to preserve the whole head of the person as attempting to remove the brain from the scull from a person would only make an unnecessary extra risk of accidentally creating additional damage to the brain. Even then, cryogenic preservation should only be all about preserving the brain itself and we must regard the preservation of the other parts of the persons head as almost irrelevant. We must only consider how well the cryogenic preservation preserves the human brain.
It is my judgement that the conventional method of cryogenically preserving humans is doomed to fail because, no mater how advanced technology becomes in the future, the laws of physics indirectly conspire to make it impossible for there to ever be a practical way of repairing the microscopic damage done to the human brain as a direct result the conventional method of freezing the brain.
As far as I am aware, the microscopic damage done to the human brain by conventional method of cryogenically preserving humans is mainly in three forms:
1, as ice crystals grow, they can pierce delicate structures such as cell membranes.
2, as ice crystals grow on the outside of a brain cell, they absorb moisture away from that brain cell causing that brain cell to be severely dehydrated.
3, as ice crystals grow, they expand and, as they expand, this inevitably leads to uneven expansion in the brain with some parts expanding faster than other parts. This uneven expansion as the brain freezes solid leads to tension building up which then leads to micro fractures. Each one of these micro fractures can sever millions of blood vessels, neurons and nerve fibres.
There are several reasons why this may mean that, no mater how advanced technology becomes in the future, it cannot repair the damage. I will only disuse some of these reasons here:
The ‘access problem’
One reason why future technology cannot repair this damage is because of what I call the ‘access problem’: suppose, in the far future with extremely advanced technology, we consider how we are to repair a particular brain cell that is located somewhere within the centre of the cryogenically frozen human brain and which is completely surrounded by frozen brain tissue. To physically repair that brain cell, one of the minimum requirements is that we must surely be able to directly physically access it by touching it with something solid such as some kind of tool or machine that is designed to repair it. I believe that it is a safe assumption that it would not be physically possible to repair it remotely without anything actually solid touching it -no mater how advanced technology becomes!
But in order to make something physically touch that brain cell, it would have to be made to pass through all the brain tissue that surrounds it and this is when the problems begin: with no way of making something solid pass through the surrounding tissue without doing considerable more damage to that tissue, by making something solid pass through the surrounding tissue and repairing that cell you would, in fact, be increasing the total amount of damage. So, metaphorically speaking, to even begin to repair the brain, you have to take a hundred steps back before you can make one step forward. Even with the most advanced technology, his would surely make repairing the brain a technical nightmare if not physically impossible.
I am tempting to consider, as a solution to this problem, slicing up the brain into extremely thin slices (so as to make the distance between any given brain cell and the outside a extremely short one) before repairing each slice and then somehow fix the slices back together again. But, obviously, this slicing process would do considerable more damage not least by severing brain cell connections/fibres.
Also, do you slice up the brain before or after thawing it? If you do it before thawing it, then it would be as brittle as glass and there would be the risk of creating yet more damage. If you do it after thawing it, then, as soon as you thaw it, chemical degradation will start to occur so you better then act fairly fast. And then there is the problem of fixing the slices back together again: how do you know which broken end of a brain cell fibre in one layer is supposed to connect to which broken end of the corresponding brain cell fibre in the adjacent layer? After all, nature does not conveniently give each connection a unique identification tag and one connection looks pretty much like another!
However, there is a solution to this access problem: why not pump fluid down the blood vessels in the brain that is carrying some tiny things, either tiny machines or genetically engineered cells, and these tiny things access each brain cell from the nearest capillary blood vessel to it? Without exception, all brain cells are only a very short distance from at least one blood vessel so it should be possible to make something go from the inside of the blood vessel to the brain cell while causing minimum or even no damage.
But, this relies on the blood vessels being unbroken and, unfortunately, the usual procedure to cryogenically preserving a human brain causes micro fractures that sever blood vessels (not to mention that they also sever nerve fibres). Because of tiny movements during freezing and thawing, the broken ends of the smaller blood vessels may not even stay in line. This would mean that if you attempted to pump fluid down those blood vessels carrying something, the fluid would just spill out where you would not want it to go and this may even cause yet more damage.
My conclusion here is that the only solution to this access problem is to find a way of preserving the brain without micro fractures and thus keep all the blood vessels unbroken otherwise it would be extremely difficult if not totally impossible for future technology to repair the damage no mater how advanced it becomes!
The ‘soft preservation’ of the human brain
One way preserving the brain without causing micro fractures is to fill the brain with the most powerful non-toxic but highly concentrated antifreeze mix that is designed to have a freezing point as low as possible and then, instead of freezing the brain solid, the brain is merely cooled to a temperature just above that freezing point, and then keeping the temperature permanently at that temperature and never actually freeze the brain solid. I personally like to call this ‘soft preservation’ as opposed to what I like to call ‘hard preservation’ because his would leave the brain with a soft rather than a frozen-hard consistency.
This idea has some advantages and disadvantages:
Its advantage is that it would certainly solve the access problem as the blood vessels would not be severed by any micro fractures. It would also stop ice crystals from forming and thus doing microscopic damage. There would also be the interesting advantage that, if, later on, a better antifreeze mix is invented, perhaps one that allows the brain to be frozen solid without micro fractures, because the blood vessels would still be unbroken, it would be perfectly practical to pump the blood vessels with the new improved antifreeze mix to replace the now old obsolete antifreeze mix.
But there is a serious disadvantages with this ‘soft preservation’ : it may result in slow chemical degradation of the cryogenically preserved brain though centuries of storage. There are two reasons for this:
firstly, I think it is unlikely that a non-toxic antifreeze mix that it fully soluble in water can be made to have a freezing point as low as liquid nitrogen temperature (although I would really like to be proven completely wrong!). That would mean that the brain couldn’t be ...
...This post does not allow me to add the rest of the words I wont to post because the article that I wont to send contains too many words. Can anyone tell me how I can send my article in the form of a compressed attachment? If not, can anyone tell me how to delete this post?
The usual procedure to cryogenically preserving a human body is to first cool the body then remove all the blood with the help of an ‘anticoagulant’ (which is a substance that prevents the blood clotting and, in this case, must be administered before the blood clots after death) and then, by pumping antifreeze solution through these blood vessels, replace the moisture in the body with an antifreeze solution designed to minimise the damage done through freezing and then, finally freeze the body down to liquid nitrogen temperature and keep it that temperature until if or when future technology can become so advanced that it can repair the damage and resurrect the person.
In the future, if technology ever becomes so advanced that it can perform the formidable task of repairing the microscopic damage done to the human brain as a direct result of freezing the brain then it must surely have become more than advanced enough to perform the comparatively much less formidable task of replacing every organ in the body with organs grown in a laboratory. Obviously, if future technology cannot repair the human brain then there is no hope of bringing the frozen person back because there would be no point in replacing the brain! Therefore, if we cryogenically freeze a human then there would be no point in doing so without the assumption that future technology not only would be able to repair the brain but would also be able to replace the whole body except the brain.
Therefore, it only makes sense to cryogenically preserve the brain of the person and not the body although, in practice, it would be easier to preserve the whole head of the person as attempting to remove the brain from the scull from a person would only make an unnecessary extra risk of accidentally creating additional damage to the brain. Even then, cryogenic preservation should only be all about preserving the brain itself and we must regard the preservation of the other parts of the persons head as almost irrelevant. We must only consider how well the cryogenic preservation preserves the human brain.
It is my judgement that the conventional method of cryogenically preserving humans is doomed to fail because, no mater how advanced technology becomes in the future, the laws of physics indirectly conspire to make it impossible for there to ever be a practical way of repairing the microscopic damage done to the human brain as a direct result the conventional method of freezing the brain.
As far as I am aware, the microscopic damage done to the human brain by conventional method of cryogenically preserving humans is mainly in three forms:
1, as ice crystals grow, they can pierce delicate structures such as cell membranes.
2, as ice crystals grow on the outside of a brain cell, they absorb moisture away from that brain cell causing that brain cell to be severely dehydrated.
3, as ice crystals grow, they expand and, as they expand, this inevitably leads to uneven expansion in the brain with some parts expanding faster than other parts. This uneven expansion as the brain freezes solid leads to tension building up which then leads to micro fractures. Each one of these micro fractures can sever millions of blood vessels, neurons and nerve fibres.
There are several reasons why this may mean that, no mater how advanced technology becomes in the future, it cannot repair the damage. I will only disuse some of these reasons here:
The ‘access problem’
One reason why future technology cannot repair this damage is because of what I call the ‘access problem’: suppose, in the far future with extremely advanced technology, we consider how we are to repair a particular brain cell that is located somewhere within the centre of the cryogenically frozen human brain and which is completely surrounded by frozen brain tissue. To physically repair that brain cell, one of the minimum requirements is that we must surely be able to directly physically access it by touching it with something solid such as some kind of tool or machine that is designed to repair it. I believe that it is a safe assumption that it would not be physically possible to repair it remotely without anything actually solid touching it -no mater how advanced technology becomes!
But in order to make something physically touch that brain cell, it would have to be made to pass through all the brain tissue that surrounds it and this is when the problems begin: with no way of making something solid pass through the surrounding tissue without doing considerable more damage to that tissue, by making something solid pass through the surrounding tissue and repairing that cell you would, in fact, be increasing the total amount of damage. So, metaphorically speaking, to even begin to repair the brain, you have to take a hundred steps back before you can make one step forward. Even with the most advanced technology, his would surely make repairing the brain a technical nightmare if not physically impossible.
I am tempting to consider, as a solution to this problem, slicing up the brain into extremely thin slices (so as to make the distance between any given brain cell and the outside a extremely short one) before repairing each slice and then somehow fix the slices back together again. But, obviously, this slicing process would do considerable more damage not least by severing brain cell connections/fibres.
Also, do you slice up the brain before or after thawing it? If you do it before thawing it, then it would be as brittle as glass and there would be the risk of creating yet more damage. If you do it after thawing it, then, as soon as you thaw it, chemical degradation will start to occur so you better then act fairly fast. And then there is the problem of fixing the slices back together again: how do you know which broken end of a brain cell fibre in one layer is supposed to connect to which broken end of the corresponding brain cell fibre in the adjacent layer? After all, nature does not conveniently give each connection a unique identification tag and one connection looks pretty much like another!
However, there is a solution to this access problem: why not pump fluid down the blood vessels in the brain that is carrying some tiny things, either tiny machines or genetically engineered cells, and these tiny things access each brain cell from the nearest capillary blood vessel to it? Without exception, all brain cells are only a very short distance from at least one blood vessel so it should be possible to make something go from the inside of the blood vessel to the brain cell while causing minimum or even no damage.
But, this relies on the blood vessels being unbroken and, unfortunately, the usual procedure to cryogenically preserving a human brain causes micro fractures that sever blood vessels (not to mention that they also sever nerve fibres). Because of tiny movements during freezing and thawing, the broken ends of the smaller blood vessels may not even stay in line. This would mean that if you attempted to pump fluid down those blood vessels carrying something, the fluid would just spill out where you would not want it to go and this may even cause yet more damage.
My conclusion here is that the only solution to this access problem is to find a way of preserving the brain without micro fractures and thus keep all the blood vessels unbroken otherwise it would be extremely difficult if not totally impossible for future technology to repair the damage no mater how advanced it becomes!
The ‘soft preservation’ of the human brain
One way preserving the brain without causing micro fractures is to fill the brain with the most powerful non-toxic but highly concentrated antifreeze mix that is designed to have a freezing point as low as possible and then, instead of freezing the brain solid, the brain is merely cooled to a temperature just above that freezing point, and then keeping the temperature permanently at that temperature and never actually freeze the brain solid. I personally like to call this ‘soft preservation’ as opposed to what I like to call ‘hard preservation’ because his would leave the brain with a soft rather than a frozen-hard consistency.
This idea has some advantages and disadvantages:
Its advantage is that it would certainly solve the access problem as the blood vessels would not be severed by any micro fractures. It would also stop ice crystals from forming and thus doing microscopic damage. There would also be the interesting advantage that, if, later on, a better antifreeze mix is invented, perhaps one that allows the brain to be frozen solid without micro fractures, because the blood vessels would still be unbroken, it would be perfectly practical to pump the blood vessels with the new improved antifreeze mix to replace the now old obsolete antifreeze mix.
But there is a serious disadvantages with this ‘soft preservation’ : it may result in slow chemical degradation of the cryogenically preserved brain though centuries of storage. There are two reasons for this:
firstly, I think it is unlikely that a non-toxic antifreeze mix that it fully soluble in water can be made to have a freezing point as low as liquid nitrogen temperature (although I would really like to be proven completely wrong!). That would mean that the brain couldn’t be ...
...This post does not allow me to add the rest of the words I wont to post because the article that I wont to send contains too many words. Can anyone tell me how I can send my article in the form of a compressed attachment? If not, can anyone tell me how to delete this post?