Cryonics – what is it all about?
Cryonics – what is it?
Not everyone’s cup of tea, but it is of increasing interest. So if you relly want to know, here goes for an explanation of the cryonics process.
Firstly, the clinically and legally deceased patient is placed in an ice water bath.
Then blood circulation and breathing are artificially restored by a heart-lung resuscitator.
A combination of simultaneous cardiopulmonary support (CPS, similar to CPR) and rapid cooling are especially effective for protecting the brain during cardiac arrest. Intravenous lines are established and protective medications are administered.
If the patient is in a hospital, they are moved to an alternate location while CPS and cooling are maintained without interruption. Femoral arteries and veins may be used to replace blood with an organ preservation solution, and to speed cooling.
At Alcor a physician or veterinary surgeon connects major blood vessels to a perfusion circuit. A cryoprotectant solution is circulated through all blood vessels. The solution partly replaces water inside cells. The cryoprotectant concentration is gradually increased over two hours to one half the final target concentration. A rapid increase to the final unfreezable concentration is then made. Temperature, pressure, and cryoprotectant concentration data are continuously monitored by computer.
The status of the brain is visually monitored through two small holes in the skull made using a standard neurosurgical tool (14 mm Codman perforator). This permits verification of brain perfusion and observation of the osmotic response of the brain.
After cryoprotective perfusion, patients are cooled under computer control by moving nitrogen gas at a temperature of -110°C. The goal is to cool all parts of the patient below -100°C as quickly as possible to minimize any ice formation. This requires several hours. The patient is then further cooled to -196°C over approximately two weeks. Patients are monitored by sensitive instruments during this long cooling period to detect fracturing events that tend to occur when large objects are cooled below the glass transition temperature.
Following cooling, patients are then transferred into liquid nitrogen at a temperature of ‑196°C. They are thereafter kept in Alcor’s Patient Care Bay. Since Alcor uses liquid nitrogen to keep cryonics patients cold, electricity is not required for current patient care systems.
Some or all of these procedures, except for cooling, may be impossible if a patient experiences legal death without a cryonics team standing by. Depending written preferences of the member, cryopreservation may still proceed to preserve remaining brain information as best as possible under prevailing circumstances.