question: Why haven't we discovered how to put someone in cryogenic sleep
comment: Because for now, cryotechnology is only used on people who already died. In hopes of being abled to revive a dead person in the future. We can't currently freeze someone without them dying, there is no such thing (yet) as freezing a body to stop all functions including brainfunction, and being able to start all of that back up after thawing without any damage.
passages: In 2004, the technology was pioneered in the midwest United States at Miami Valley Hospital in Dayton, Ohio by Mark Krebs, MD, FACC, Matthew Hoskins, RN, BSN and Ken Peterman, RN, BSN. These electrophysiology experts were successful in curing the first 12 candidates in their facility.
   Since 2012, the use of cryogen-free magnet technology has greatly reduced infrastructure requirements and dependency on the availability of increasingly hard to obtain cryogenic coolants.
   As of 2014, about 250 corpses have been cryogenically preserved in the U.S., and around 1,500 people have signed up to have their remains preserved. As of 2016, four facilities exist in the world to retain cryopreserved bodies: three in the U.S. and one in Russia.
  
  Section::::Obstacles to success.
  
  Section::::Obstacles to success.:Preservation damage.
   Two Advanced Cryogenic Evolved Stage (ACES) concepts were originally proposed in 2006 by both Boeing and Lockheed Martin.
   Section::::Whole body cryotherapy.:Adverse effects.
  
  Reviews of whole body cryotherapy have called for research studies to implement active surveillance of adverse events, which are suspected of being underreported. If the cold temperatures are produced by evaporating liquid nitrogen, there is the risk of inert gas asphyxiation as well as frostbite.
  
  Section::::Whole body cryotherapy.:Partial body.
  
  Partial body cryotherapy (PBC) devices also exist. If the cold temperatures are produced by evaporating liquid nitrogen, there is the risk of inert gas asphyxiation as well as frostbite.
  
  Section::::See also.
  
  BULLET::::- Cryonics
  
  BULLET::::- Cold shock response
  
  BULLET::::- Cold compression therapy
  
  Section::::External links.
   Additionally, efforts are underway to preserve humans cryogenically, known as cryonics. For such efforts either the brain within the head or the entire body may experience the above process. Cryonics is in a different category from the aforementioned examples, however: while countless cryopreserved cells, vaccines, tissue and other biological samples have been thawed and used successfully, this has not yet been the case at all for cryopreserved brains or bodies. At issue are the criteria for defining "success".
   Outside the cryonics community, many scientists have strong skepticism toward cryonics methods. Cryobiologist Dayong Gao states that "we simply don't know if (subjects have) been damaged to the point where they've 'died' during vitrification because the subjects are now inside liquid nitrogen canisters." Biochemist Ken Storey argues (based on experience with organ transplants), that "even if you only wanted to preserve the brain, it has dozens of different areas, which would need to be cryopreserved using different protocols."
  
  Section::::Obstacles to success.:Revival.
   , the internal combustion engine to be used to power the IVF system on ACES will be produced by Roush Racing.
  
  In August 2016 ULA's President and CEO Tory Bruno said both Vulcan and ACES were intended to be human rated.
  
  Section::::Possible applications.
   When comparing KrioRus and Alcor, journalists call the first company Lada of the world of cryonics, and the second one — Mercedes-Benz. Alcor cryonics is the largest cryonics company in the world, twice a week it conducts tours of its premises, demonstrating the operating room (where vitrification and freezing are conducted), as well as long-term cryopatients' storage facilities, where they could just be seen through bulletproof glass. On the other side, KrioRus does not offer any such services.
   Relatively few stories have been published concerning using cryonics for medical time travel. In the Edgar Allan Poe story mentioned above (1845), the electrically-revived mummy mentions that his Egyptian civilization uses mummification for time travel.
  
  The most in-depth novel based on contemporary cryonics is national best-seller "The First Immortal" by James L. Halperin (1998). Giles Milton's 2014 thriller, "The Perfect Corpse" is set in a fictional cryonics laboratory in Nevada; the narrative revolves around the resurrection of a perfectly frozen body discovered in the Greenland ice sheet.
  
  Section::::Film.
   For people looking to find thermal profiles for cryogenics, a number of companies maintain thermal profiles of various products that are updated for accuracy at least a few times a year with their ongoing research, including data from independent trials and studies. However, obtaining these profiles is sometimes difficult if they are not used for educational purposes (mainly institutional research), as they typically only provide the updated profiles to their longtime "service center" partners around the world.
   Cryonics procedures can begin only after clinical death, and cryonics "patients" are legally dead. Cryonics procedures ideally begin within minutes of death, and use cryoprotectants to prevent ice formation during cryopreservation. It is however not possible for a corpse to be reanimated after undergoing vitrification, which causes damage to the brain including its neural networks. The first corpse to be frozen was that of Dr. James Bedford in 1967. As of 2014, about 250 bodies were cryopreserved in the United States, and 1,500 people had made arrangements for cryopreservation after their legal death.
  
  Section::::Conceptual basis.
   Section::::Results.
  
  Cryosurgery is a minimally invasive procedure, and is often preferred to more traditional kinds of surgery because of its minimal pain, scarring, and cost; however, as with any medical treatment, there are risks involved, primarily that of damage to nearby healthy tissue. Damage to nerve tissue is of particular concern.
   BULLET::::- Sleeper ship proposals call for freezing adult humans. While there is research into hibernation, the complexity of a living fully developed human body may make the sleeper ship proposals much more difficult.
   Company representatives attitude to the possibility of "resurrection" is described by them as follows (in reply to the question: "Doesn't cryonics give false hope?"): "There is no concrete evidence as to whether the development of cryonics would end in is success or will it fail. But the fact that the concept of cryonics is currently dependent upon a yet unknown science of the future, and that its success cannot be guaranteed, it is not the same as its guaranteed failure ".
   Liquefaction of gas is a power-intensive operation of cryogenic technology. The future lepton and the hadron colliders would make intensive use of low-temperature superconducting devices, operated at 4.5 K and 1.8 K, requiring very large-scale distribution, recovery, and storage of cryogenic fluids.
  
  As a result, the cryogenic systems that have to be developed correspond to two to four times the presently deployed systems and require increased availability and maximum energy efficiency. Any further improvements in cryogenics are expected to find wide applications in medical imaging techniques.
   The first human body to be frozen with the hope of future revival was James Bedford's, a few hours after his cancer-caused death in 1967. Bedford is the only cryonics patient frozen before 1974 still preserved today.
  
  Section::::Temperature.
   The cryonics argument that death does not occur as long as brain structure remains intact and theoretically repairable has received some mainstream medical discussion in the context of the ethical concept of brain death and organ donation.
  
  Cryonics uses temperatures below −130 °C, called cryopreservation, in an attempt to preserve enough brain information to permit future revival of the cryopreserved person. Cryopreservation may be accomplished by freezing, freezing with cryoprotectant to reduce ice damage, or by vitrification to avoid ice damage. Even using the best methods, cryopreservation of whole bodies or brains is very damaging and irreversible with current technology.
   Cryopreservation was applied to human cells beginning in 1954 with frozen sperm, which was thawed and used to inseminate three women. The freezing of humans was first scientifically proposed by Michigan professor Robert Ettinger when he wrote "The Prospect of Immortality" (1962). In April 1966, the first human body was frozen—though it had been embalmed for two months—by being placed in liquid nitrogen and stored at just above freezing. The middle-aged woman from Los Angeles, whose name is unknown, was soon thawed out and buried by relatives.
   BULLET::::- Dr Arthur W. Rowe, Ph.D, Professor of Forensic Medicine, New York University Medical School
  
  BULLET::::- Terry Katz, Alcor Member
  
  BULLET::::- Aubrey de Grey, Ph.D, Biomedical Gerentologist
  
  BULLET::::- Gregory Fahy, Ph.D Vice President and Chief Scientific Officer, 21st Century Medicine
  
  BULLET::::- Regina Pancake, Head of Alcor Stabilisation Team, South California
  
  BULLET::::- Tilly Nydes
  
  BULLET::::- Robin Nydes, Alcor Member
  
  BULLET::::- Professor Ralph Merkle, Ph.D, Georgia Tech College of Computing
  
  BULLET::::- Dr James R. Baker MD, Director Michigan Nanotechnology Institute
  
  Section::::See also.
  
  BULLET::::- Gerontology
  
  BULLET::::- Cryobiology
  
  BULLET::::- Life extension
  
  Section::::External links.
  
  BULLET::::- ZigZag Productions page about the program
   Overall, cryogenic processors are radically changing the way that cryogenics used to be done. Many years ago, cryogenics was simply theoretical, with spotty results when there were improvements. Now, cryogenic processors are ensuring the accurate and consistent results for all products that are treated these days. As the technology sector improves, cryogenic processors will only get better as they benefit from new computer systems. Ongoing research in the future will also improve their temperature treatment profiles.
  
  Section::::See also.
  
  BULLET::::- Absolute zero
  
  BULLET::::- Cryogenics
  
  BULLET::::- Cryogenic tempering
  
  BULLET::::- Cryocoolers
  
  BULLET::::- Coldest temperature achieved on earth
  
  BULLET::::- Refrigeration
  
  BULLET::::- Superfluidity
  
  BULLET::::- Superconductivity
   The term “cryotank” refers to storage of super-cold fuels, such as liquid oxygen and liquid hydrogen. Cryotanks and cryogenics can be seen in many sci-fi movies, but they are still currently undeveloped. All that needs to be done is for a human to be loaded into the tank and then they can be frozen until a time comes when any diseases they have can be cured and they can live an even longer life. This could also be used in space travel and just preserving human life in general. The problem with this is when the human body is frozen, ice crystals form in the cells. The ice crystals then continue to expand rupturing the cell wall and destroying the integrity of the cell, or killing it.
   Cryonics requires unknown future technology to repair or regenerate tissue that is diseased, damaged, or missing. Brain repairs in particular will require analysis at the molecular level. This far-future technology is usually assumed to be nanomedicine based on molecular nanotechnology. Biological repair methods or mind uploading have also been proposed.
  
  Section::::Cryonics in practice.
  
  In conventional cryobiology practice, long-term preservation of biological tissue can be achieved by cooling to temperatures below . Immersion in liquid nitrogen at a temperature of is often used for convenience.
   Those who believe that revival may someday be possible generally look toward presently-nonexistent bioengineering, molecular nanotechnology, or nanomedicine as key technologies. Revival would require repairing damage from lack of oxygen, cryoprotectant toxicity, thermal stress (fracturing), freezing in tissues that do not successfully vitrify, and reversing the cause of death. In many cases extensive tissue regeneration would be necessary.
   There was strong resistance to taking cryonics into high technology too quickly, within CSC, and there were other problems, including almost total secrecy as to how CSC's decisions were made and how it was organized and operated. By the summer of 1971, these stresses were beginning to weaken their confidence in CSC, and they felt that they were forced to withdraw from it and pursue some other route.
  
  Section::::Fred's father.
  