时间:2011-06-14 18:54 作者:admin 来源:www.2abc8.com
新型潜水服让人像鱼一样呼吸氧化液体（中英文）Into the abyss: The diving suit that turns men into fish
Now an inventor in the United States believes he has solved the riddle of how to get humans down to serious depths – by getting us to breathe liquid like fish.
Arnold Lande, a retired American heart and lung surgeon, has patented a scuba suit that would allow a human to breathe “liquid air”, a special solution that has been highly enriched with oxygen molecules.
The idea immediately conjures up the terrifying spectre of drowning but our lungs are more than capable of taking oxygen from a solution.
“The first trick you would have to learn is overcoming the gag reflex,” explains Lande, a 79-year-old inventor from St Louis, Missouri. “But once that oxygenated liquid is inside your lungs it would feel just like breathing air.”
Lande envisages a scuba suit that would allow divers to inhale highly-oxygenated perfluorocarbons (PFCs) – a type of liquid that can dissolve enormous quantities of gas. The liquid would be contained in an enclosed helmet that would replace all the air in the lungs, nose and ear cavities.
The CO2 that would normally exit our body when we breathe out would be “scrubbed” from our blood by attaching a mechanical gill to the femoral vein in the leg.
By using oxygen suspended in liquid, divers would no longer have to worry about decompression sickness - the often fatal condition known as “the bends” which occurs when nitrogen dissolved in the blood under the immense pressures of deep water bubbles out as we rise. It could potentially allow them to descend to far greater depths than is currently possible.
Liquid ventilation might sound like science fiction – it played a major role in James Cameron’s 1989 sci-fi film The Abyss – but it is already used by a handful of cutting-edge American hospitals for highly premature babies.
Children born before 28 weeks have huge difficulties breathing, often because their lungs are not developed enough to comfortably adjust from the liquid environment of the womb to inhaling gaseous air. Immature alveoli, the final branchings inside the lung that feed oxygen into the blood, lack vital surfactants which stop the tiny cavities sticking together when we breathe out.
In response doctors have begun experimenting with highly-oxygenated PFCs with remarkable success.
Professor Thomas Shaffer, a paediatrics specialist from Delaware, has experimented with liquid breathing since the late 1970s. He spent much of his early career testing various animals in oxygenated PFCs.
Place a mouse in oxygenated liquid and instinct immediately kicks in as the animal flounders wildly. Everything the mouse has ever learned screams at it to avoid inhaling a solution it thinks will kill it.
Yet when we drown there comes a moment when the instinct not to breathe liquid is overridden by a stronger instinct to take in one last breath. It is a desperate final attempt to get oxygen into the blood. If the liquid we are in contains oxygen molecules that happily cross from the solution into our blood stream, life will return. After all, it is not water that kills us when we drown. It’s our inability to take oxygen from the water that condemns us.