Cryonics, July 1988

by Mike Darwin

[What follows is a purely speculative exploration of how revival might be carried out for patients frozen with 1980s technology. Patients cryopreserved today with modern vitrification methods under good conditions will require less extensive repairs than described here.]

Prelude

It has been a long, hard battle. First youth slipped away to be replaced by old age, with all its limitations. Finally, inside some nameless cell, a change occurs. A few atoms become misarranged and the instructions governing the cell’s operation and replication suffer a critical error. The error propagates as the cell begins to divide blindly. Millions, then billions of copies of the errant cell are made. Vital structures are displaced and damaged, toxic molecules are spewed forth, resulting in the death of countless normal cells and the inability of many others to perform properly.

Chemotherapy and radiaion therapy fail to stem the rising tide of cancer. A man is dying and there is nothing that 20th century medicine can do to reverse his decline.

A heart stops. A physician gives up and pronounces death. But it is not the end. Unlike most of his contemporaries, the old man with the stilled heart and the malignancy which caused it has looked into the futre unflinchingly — with vision and foresight. Waiting outside the hospital room where the patient lies is a cryonics transport team.

The Journey Begins

The transport team restores circulation and breathing with CPR, connects the patient to a portable heart-lung machine and begins cooling him. He is taken to a cryonics facility where he is connected to another heart-lung machine, more elaborate than the first. Gradually, a little less than half the water in his body is replaced with cryoprotective drugs. He is cooled to the boiling point of liquid nitrogen and placed within a protective vault to continue his march through time — unchanging.

The chemistry inside the man’s cells is stopped. Time is stopped for him. But not for the rest of the world. Outside his frozen sanctuary, the march of time goes on. Countless other terminal patients are abandoned, and allowed to slip away forever. Not all, however. Less than a decade after his entry into cryonic suspension another patient joins him: his wife.

The decades slide by. Driven by medical, military, and industrial pressures, human technology increasingly comes to grips with engineering on a molecular level. Physicians wishing ever better ways to monitor their patients demand smaller and smaller devices which researchers are increasingly able to deliver. The demand for ever smaller and faster computers with increasingly compact memories leads to the development of very small electronic devices. The need to repair living tissue that has suffered trauma and disease results in increasingly sophisticated medical therapies and surgical tools. Within two decades from the time the patient entered suspension a cure for his cancer is developed. The molecular basis of cancer is unraveled, and medicine becomes equal to the task of turning off the genes which cause errant cell division and lead to tumor growth and death.

But the patient in suspension cannot be revived yet. His problem is not so much the cancer as it is the injury inflicted by the immature technology that was used to suspend him. He must continue to wait. Fortunately, chilled to the temperature of liquid nitrogen, he can wait for centuries if need be.

Revival

A little more than 100 years has passed since darkness enveloped the dying man in the hospital. A full-fledged technology of cell repair is now available. Ultra-sophisticated microscopic repair devices routinely patrol human tissue, repairing injury and destroying disease organisms. Indefinite youth and good health are the birthright of everyone.

The patient from the 1980’s is removed from the icy vault that has held him for over a century. Slowly his temperature is raised to -130øC, and his head is separated from the rest of his aged, diseased body with a high speed surgical saw and transferred the fluid-filled receiving chamber of the revival unit. The fluid in the receiving chamber is tetrafluoromethane; a compound which is liquid even at -130øC. The revival unit appears a combination of living creature and inorganic machine. An Artificial Intelligence, its “brain” contains the sum of all human medical knowledge, which it keeps updated with its link to the worldwide medical information net.

Connections are established between the patient’s neck and the revival unit. Repairs begin. Countless millions of microscopic devices designed to operate at low temperatures begin to clear out ice from the patient’s blood vessels. As they proceed, they assemble behind them fine fibers of electrically conductive polyacetylene which supply power to the ice removal devices. Later these fibers will serve as communications links as well.

Once the circulatory system of the patient is free of ice, billions of nanocomputers (cell-sized computers) are moved into strategic positions along the network of conducting fibers. These interconnected computers will coordinate both short-range and long-range repair activities (such as repair of gross fractures). All these processes are carried out sufficiently slowly so that the patient’s temperature does not rise significantly above -130øC: the tissues beyond his blood vessels remain virtually unchanged from the time of his suspension.

New, more sophisticated devices, are introduced. Capillary walls are partially disassembled, and the devices begin to enter the inter-cellular spaces of the brain. These devices also remove ice, but much more carefully than the earlier ones. As ice crystals are disassembled at the molecular level, information concerning their position and orientation is transmitted back to supervising nanocomputers waiting in nearby blood vessels. When biological structures such as cell membranes or dendrite debris are encountered, they are carefully examined and tagged with special identifying molecules, and anchored to nearby cells if necessary. Their original position is also relayed back to the supervising computers and to the revival unit.

A week has now passed. Virtually all the ice has been removed from the patient’s brain, and cryogenic fluid now freely circulates throughout the extracellular environment. The patient’s temperature is now raised until the contents of his cells become a thick liquid (at about -100øC). Devices for the first time begin to enter cell interiors. Their purpose is to lock up metabolic machinery to prevent premature, uncoupled activity. Enzymes are physically bonded to cell structures, and their active sites are blocked by specially fabricated molecules until repairs are completed.

Once cell interiors have been adequately stabilized, the tetrafluoromethane is replaced with another solvent, and the patient’s temperature is raised above the freezing point of water. Trillions of repair devices are now deployed. In sizes ranging from that of large molecules to small cells, the devices take up strategic positions both inside and outside cells. Among these devices are nanocomputers which will now supervise repairs from inside cells.

With the repair system now in essentially complete control of the patient’s brain, the most sophisticated operations begin. Small devices examine molecules and report their structures to larger controlling devices. Molecular damage due to oxygen and nutrient starvation (ischemia), freezing, and even aging is repaired by nanocomputer-directed repair enzymes. Independent DNA copies are obtained from many different cells, and DNA in these cells is restored to the damage-free sequence of youth inferred by nanocomputer comparison. As repairs proceed, virtually no cellular defects escape the detection and correction of the repair system.

While repairs proceed inside cells, disrupted external structures are restored on the basis information obtained during the ice removal process. Torn membranes are mended, disrupted cell connections restored, and gross fractures are repaired by microscopic surgeons which operate at a level a million times finer and more sophisticated than surgeons today. Where cells have been lost due to aging or other injury, new ones are fabricated and proper connections made. Gradually, over the course of several months, the patient’s brain is restored to a healthy state.

As repairs near completion, larger devices are removed, capillary membranes are repaired, and the network of nanocomputers and communications fibers is disassembled. A blood supply grown from the patient’s own cells by the revival unit now begins to circulate, and the temperature is stabilized at 37øC (98.6øF). Cell metabolism is restarted by selective unblocking of enzymes inhibited during the repair process, although consciousness is still suppressed by circulating chemicals which inhibit critical steps in nerve cell metabolism. The patient — an exposed pearly white brain floating within the womb of the revival unit — is now ready for the final phase of the revival process.

On the surface of his brain a single cell begins to divide. Unlike the cancer which threatened the patient’s life, the division of this cell is orderly and planned to restore life. A layer of dividing cells covers the restored but unconscious brain. The cells begin to differentiate, and slowly, like a newly conceived child, a body begins to take shape within the revival unit.

Awakening

Just a little over a year from the start of the revival procedure, the patient awakens in his hospital bed. He returns to consciousness slowly, suffused in a warmth and sense of security which seems strangely at variance with his remembered prognosis. His last memory is of going to sleep a few days before his suspension over a century ago. He slowly opens his eyes and is greeted by a face that seems strangely familiar but which he cannot quite place.

A familiar voice calls out his name. Instantly there is recognition. It is his wife. But she is not as she was. She is young and beautiful again. More beautiful even than he remembered. An instant before he was trapped in a dying body. Now, he is alive and well and looking into the eyes of someone he loves. He glances down at has his hands and at the contours of the sheet covering his body. He too is young again. He has made the trip successfully.

In an instant, in the blink of an eye he has found his way into the future. An open-ended future of unlimited lifespan and unbounded possibilities.