Cryogenics refers to the branches of physics and engineering that study very low temperatures, how to produce them, and how materials behave at those temperatures. Cryogenics is all about temperatures below -150°C or 123 K. One of the most amazing applications of cryogenic processing is cryonics: where the human body is exposed to cryogenic treatment in order to preserve it after death. In the United States of America, there are, currently, two organizations that offer cryogenic treatment for human bodies: The Cryonics Institute in Clinton Township, Michigan and Alcor in Scottsdale, Arizona.
Once death sets in, the patient’s bodies are preserved in chemicals designed to theoretically protect cellular structure, before being lowered into steel tubes of liquid nitrogen, called dewars. Here they will be kept in ‘cold storage’ at – 196°C in the hope that someday in the future they may be brought back to life. There are currently 147 people in cryogenic suspension, with another 1,000 members signed up for the deep freeze. History of Human Cryogenics:
In 1940, pioneer biologist Basil Luyet published a work titled “Life and Death at Low Temperatures” in which he observed that while many organisms underwent serious damages at very low temperatures. However, in some cases, he reported that he managed to restore normal function when organisms were rewarmed after freezing. Luyet’s work led to a whole new area of science called cryobiology. British scientists found that by soaking cells in a solution of glycerol, red blood cells and bull semen could be frozen and then their functions could be completely restored on rewarming.
The main discovery is that through human cryogenics, life can, in fact, be stopped and restarted under controlled conditions. In the United States, Robert Ettinger through his book “The Prospect of Immortality” (1964) promoted the idea that a person frozen after legal death might rationally hope to be resuscitated at some time in the far future when medicine has advanced enough to cure most diseases, reverse the aging process, and repair any residual damage caused by freezing (Klein, 2004). This came to be known as Ettinger’s concept.
Many scientists shun the idea of manipulating life and death conditions of the body and hence there has not been much progress in this field since the 1960s. Cryonics is an unproven theory. There are scientific obstacles that, some would say, are insurmountable. One of the success stories in this realm is that of Gregory Fahy and his team. They have succeeded in cryopreserving a rabbit kidney, reversed the procedure and successfully re-implanted it without losing the ability to sustain the life of the recipient (Fahy, 2006). Challenges in Cryonics: Cryonic aspirants may choose to have their entire body stored or only their head frozen.
The thinking behind the latter option is that an old person would not want to come back alive in his old body. Cryonics is an expensive option. Alcor currently charges the equivalent of ? 80,000 for the full body option and ? 42,000 for the head only (Cryonics Cryogenics, 2006). The long-term storage of biological materials, including human organs, requires very low temperatures, which typically are achieved with liquid nitrogen (LN2). While LN2 provides suitable ultralow temperatures, general storage environments have been less than satisfactory and this is an obstacle in cryonics (Lehr, 2006).
Another major challenge facing cryonics is that the current technique of full-body preservation with cryoprotectant chemicals causes extensive molecular damage to the body. To successfully bring a patient back to life, cryonics would not only need to reverse this damage, but would also have to cure
” (Best, 2006) Cryopreservation Procedure: As soon as a patient dies, the person’s brain cells are the first to die. Hence the first step would be to stop cellular decomposition caused by oxygen deprivation. This is done by cooling the body. For every 10°C drop in temperature there is a 50% reduction in metabolic demand which means it takes twice as long for damage to occur. The body should be kept just above freezing and then, a mechanical chest compressor is used to temporarily restore circulation before injecting medications to stop the blood clotting.
Then, the patient’s blood is washed out and replaced with a temporary protective fluid. Now, there is a surgical process that begins by opening the chest cavity to allow plastic cannulation tubes to be sewn into the heart to provide entry and exit points for the cryoprotectant fluid. These tubes are connected to a by-pass machine that circulates the cryopreservation fluid around the body. The process called “vitrification” involves replacing over 60% of the water in the body with, potentially toxic, preservation chemicals.
When exposed to cryogenic temperatures of below -120°C they react by turning tissue to a glass-like solid. Throughout the procedure the body is kept packed in ice inside a perspex covering. Liquid nitrogen vapor is regularly pumped around the body to keep the temperature at -3°C. After the surgery, the body is transferred to an insulated holding chamber for the rapid cool down stage. Liquid nitrogen vapor is pumped inside and probes will monitor the body’s core temperature. The temperature will be dropped rapidly to just above the glass transition point.
The body is then placed in a sleeping-bag and put into a pod which is the permanent storage container where it will be cooled very slowly to liquid nitrogen temperature (Cryonics Cryogenics, 2006). Conclusion: It has been man’s inherent nature to search for eternity and eternal youth. So, it is no wonder that the science of cryonics has captivated the interests of mankind. Cryonics is a science that is still in the nascent stage. It is a controversial science that is countered by seemingly unanswerable questions.
Yet, the fascination for conquering age and death keeps research in cryonics advancing. Bibliography: Platt, Charles (2006). Cryonics: A Short History The “Impossible” Dream. http://www. imminst. org/forum/index. php? s=&act=ST&f=61&t=860 Best, Ben (2006). Cryonics: The Issues. http://www. benbest. com/cryonics/cryiss. html Lehr, A. Valentine (2006). Precision, flexibility critical in long-term, ultra- low-temperature storage of biological materials. Control Considerations for Cryogenic Storage Facilities. HPAC Engineering. August 2006. http://www. hpac.
com/member/feature/2006/0806/0806_lehr. htm Cryonics, Cryogenics (2006). Death in the deep freeze. http://www. mymultiplesclerosis. co. uk/stranger-than-fiction/cryogenics. html Fahy, M. Gregory (2006). Cryopreservation of Complex Systems: The Missing Link in the Regenerative Medicine Supply Chain. Rejuvenation Research. Jun 2006, Vol. 9, No. 2: 279-291. http://www. liebertonline. com/doi/abs/10. 1089/rej. 2006. 9. 279? journalCode=rej= Klein, Bruce (2004). Robert Ettinger, Father of Cryonics. http://www. imminst. org/forum/index. php? act=ST&f=67&t=4112