Life Science Article - Cryonics

Jurongville Secondary School Life-Science Article: “Cryonics”

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The year is 1967. A British secret agent has been "frozen," awaiting the day when his arch nemesis will return from his own deep freeze to once again threaten the world. That day finally arrives in 1997. The agent is revived after 30 years on ice, and he saves the world from imminent destruction. You'll probably recognize this scenario from the hit movie, "Austin Powers: International Man of Mystery" (1997). Cryonics also shows up in films like "Vanilla Sky" (2001), "Sleeper" (1973) and "2001: A Space Odyssey" (1968). But is it pure Hollywood fiction, or can people really be frozen and then thawed to live on years later? The science behind the idea does exist. It's called cryogenics -- the study of what happens to materials at really low temperatures. Cryonics -- the technique used to store human bodies at extremely low temperatures with the hope of one day reviving them -is being performed today, but the technology is still at an early stage. In this article, we'll look at the practice of cryonics, learn how it's done and find out whether humans really can be brought back from the deep freeze. Cryonics is the practice of preserving human bodies in extremely cold temperatures with the hope of reviving them sometime in the future. The idea is that, if someone has "died" from a disease that is incurable today, he or she can be "frozen" and then revived in the future when a cure has been discovered. A person preserved this way is said to be in cryonic suspension.

To understand the technology behind cryonics, think about the news stories you've heard of people who have fallen into an icy lake and have been submerged for up to an hour in the cold water before being rescued. The ones who survived did so because the icy water put their body into a sort of suspended animation, slowing down their metabolism and brain function to the point where they needed almost no oxygen. Cryonics is a bit different from being resuscitated after falling into an icy lake, though. First of all, it's illegal to perform cryonic suspension on someone who is still alive. People who undergo this procedure must first be pronounced legally dead -- that is, their heart must have stopped beating. But if they're dead, how can they ever be revived? According to scientists who perform cryonics, "legally dead" is not the same as "totally dead." Total death, they say, is the point at which all brain function ceases. Legal death occurs when the heart has stopped beating, but some cellular brain function remains. Cryonics preserves the little cell function that remains so that, theoretically, the person can be resuscitated in the future.

If you decide to have yourself placed in cryonic suspension, what happens to you? Well, first, you have to join a cryonics facility and pay an annual membership fee (in the area of $400 a year). Then, when your heart stops beating and you are pronounced "legally dead," an emergency response team from the facility springs into action. The team stabilizes your body, supplying your brain with enough oxygen and blood to preserve minimal function until you can be transported to the suspension facility. Your body is packed in ice and injected with heparin (an anticoagulant) to prevent your blood from clotting during the trip. A medical team awaits the arrival of your body at the cryonics facility. Once you are transported to the cryonics facility, the actual "freezing" begins. Cryonics facilities can't simply put their patients into a vat of liquid nitrogen, because the water inside their cells would freeze. When water freezes, it expands -- this would cause the cells to simply shatter. The cryonics team must first remove the water from your cells and replace it with a glycerol-based chemical mixture called a cryoprotectant -- a sort of human antifreeze. The goal is to protect the organs and tissues from forming ice crystals at extremely low temperatures. This process, called vitrification (deep cooling without freezing), puts the cells into a state of suspended animation. Once the water in your body is replaced with the cryoprotectant, your body is cooled on a bed of dry ice until it reaches -130 C (-202 F), completing the vitrification process. The next step is to insert your body into an individual container that is then placed into a large metal tank filled with liquid nitrogen at a temperature of around -196 degrees Celsius (-320 degrees Fahrenheit). Your body is stored head down, so if there were ever a leak in the tank, your brain would stay immersed in the freezing liquid. Cryonics isn't cheap -- it can cost up to $150,000 to have your whole body preserved. But for the more frugal futurists, a mere $50,000 will preserve your brain for perpetuity -an option known as neurosuspension. Hopefully for those who have been preserved this way, technology will come up with a way to clone or regenerate the rest of the body.