Liquid breathing

This is probably already a cliche in science fiction: a suit or capsule arrives very quickly some viscous substance, and the main character suddenly discovers for himself how quickly he loses the rest of air from the lungs of its own, and its insides are filled with unusual shade of lymph fluid to the blood . In the end he even panic, but makes a few sips of instinctual, or rather sighs and is surprised to find - he can breathe this exotic blend, as if he is breathing normal air.

So whether we are far from realizing the idea Liquid breathing? Is it possible to breathe the liquid mixture, and whether this is a real need?
There are three ways to use this advanced technology: this medicine, diving to great depths and astronautics.

The pressure on the diver's body is growing every ten meters to one atmosphere. Due to a sharp decrease in pressure may begin caisson disease, which forms when the dissolved gases in the blood begin to boil bubbles. Also, at high pressures may be oxygen and nitrogen poisoning. With all this fighting using special breathing mixtures, but they do not give any guarantees, but only reduce the likelihood of unpleasant consequences. Of course, you can use the diving suits that maintain pressure on the diver's body and his breathing mix at exactly one atmosphere, but they, in turn, bulky, cumbersome, difficult movement, and also very expensive.

Liquid breathing would provide a third solution to this problem while preserving the mobility of flexible immersion suits and low risk hard suits. Respiratory liquid Unlike expensive breathing mixtures not saturate the body with helium or nitrogen gas also eliminates the need for a slow decompression to avoid decompression sickness.

In medicine, Liquid breathing can be used in the treatment of premature infants to prevent damage to immature lungs bronchus pressure, volume and concentration of atmospheric oxygen Medical ventilator. Pick up and try different mixtures to ensure the survival of a premature fetus already started in the 90's. Perhaps the use of a liquid mixture at a complete stop or partial respiratory insufficiency.

Space flight is conjugate with large congestion, and fluid pressure is evenly spread. If a person is immersed in the liquid, then the pressure overload will go on his entire body, rather than specific support (backrest, seat belts). This principle was used to create a costume for overloads Libelle, which is a hard space suit filled with water, which allows the pilot to maintain consciousness and performance even under overload above 10 g.

This method is limited by the density difference between the tissues of the human body and the liquid used for dipping, so the limit is 15-20 g. But you can go ahead and fill the lungs with liquid, close to the density of water. Completely immersed in the liquid and breathable liquid astronaut will feel relatively weak effect of extremely high accelerations, as the forces in the fluid are distributed evenly in all directions, but the effect will still be due to the different densities of tissues of the body. The limit will still remain, but it will be high.

The first experiments on Liquid breathing conducted in the 60s of the last century in laboratory mice and rats who were forced to inhale the salt solution with a high content of dissolved oxygen. This primitive mixture gave the animals to survive a certain amount of time, but she could not remove carbon dioxide, so the light causing irreparable harm to the animals.

Later work began with perfluorocarbons, and the first results were much better than the results of experiments with brine. Perfluorocarbons - organic substances in which all hydrogen atoms are replaced by fluorine atoms. Perfluorocarbon compounds have the ability to dissolve both oxygen and carbon dioxide, they are very inert, colorless, transparent, can not cause damage to lung tissue and is not absorbed by the body.

Since liquid breathing has been improved, the most perfect solution for the moment is called perflubron or "Likvivent" (commercial name). This Buttery transparent liquid with a density twice higher than the density of water has many useful features, it can carry two times more oxygen than normal air, has a low boiling point and thus use its final removal from the lungs is performed by evaporation. Alveoli are exposed to the liquid better opened and the material gains access to the contents, it improves the exchange of gases.

The lungs can fill with fluid completely, it will require a membrane oxygenator, a heating element and forced ventilation. But in clinical practice, often do not do so, and use Liquid breathing in combination with conventional gas ventilation, filling the lungs perflubronom only partially, about 40% of the total volume.

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What prevents us from using Liquid breathing? Fluid viscous and bad breath removes carbon dioxide, so you will need mechanical ventilation of the lungs. To remove carbon dioxide from the ordinary person weighing 70 kilograms required flow of 5 liters per minute and above, and it is very much in view of the high viscosity liquids. When the value of physical activity required flow will only grow, and it is unlikely people will be able to move 10 liters of fluid per minute. Our lungs are not created just for breathing and fluid pump such volumes themselves are not able to.

Using the positive features of the liquid for breathing in the aviation and space too can forever remain a dream - fluid in the lungs for a costume overload protection must have the density of water, and perflubron twice her harder.

Yes, our lungs are technically able to "breathe" a certain oxygen-rich mixture, but, unfortunately, we can only do this for a few minutes as our lungs are not strong enough to ensure the circulation of breathing gas for extended periods of time. The situation may change in the future, can only draw our hopes for researchers in this field.

According to the materials zidbits.com and en.wikipedia.org .

Source: geektimes.ru/post/241140/