Artificial gills (human)

Artificial gills are devices to let a human take in oxygen from surrounding water. This is speculative technology that has not been demonstrated in a documented fashion. Natural gills work because nearly all animals with gills are thermoconformers, so they need much less oxygen than a thermoregulator of the same size.^[1]

Methods

Several potential methods exist for the development of artificial gills. One proposed method is the use of liquid breathing with a membrane oxygenator to solve the problem of carbon dioxide retention, the major limiting factor in liquid breathing.^[2][3] It is thought that a system such as this would allow for diving without risk of decompression sickness.^[4]

They are generally thought to be unwieldy and bulky, because of the massive amount of water that would have to be processed to extract enough oxygen to supply an active diver, as an alternative to a scuba set.

An average diver with a fully closed-circuit rebreather needs 1.5 liters per minute while swimming or .64 liters of oxygen per minute while resting.^[5] As a result, at least 192 litres (51 US gal) of sea water per minute would have to be passed through the system, and this system would not work in anoxic water. Seawater in tropical regions with abundant plant life contains 5-8mg of oxygen per liter of water.^[6] These calculations are based on the dissolved oxygen content of water.

See also

• Henry's law

References

1. Why don't people have gills?
2. Landé AJ, Claff CL, Sonstegard L, Roberts R, Perry C, Lillehei CW (1970). "An extracorporeal artificial gill utilizing liquid fluorocarbon". Fed. Proc. 29 (5): 1805–8. PMID 5466244.
3. Landé, AJ (2006). "SEQUENCED, HEMOGLOBIN BASED ARTIFICIAL GILLS SYNTHETIC GILL SUPPORTS DIVER'S OR CLIMBER'S BREATHING BY CONCENTRATING O2 FROM SEAWATER OR FROM THIN AIR AT ALTITUDE, AND VENTING CO₂". Undersea and Hyperbaric Medicine (Annual scientific meeting abstract) (Undersea and Hyperbaric Medical Society). Retrieved 2009-03-22.
4. Landé, AJ (2006). "ARTIFICIAL GILL COMPLEMENTS LIQUID BREATHING FOR DIVING TO GREAT DEPTHS, WITHOUT BEING THREATENED BY THE BENDS". Undersea and Hyperbaric Medicine (Annual scientific meeting abstract) (Undersea and Hyperbaric Medical Society). Retrieved 2009-03-22.
5. Knafelc, ME. "Oxygen Consumption Rate of Operational Underwater Swimmers.". United States Navy Experimental Diving Unit Technical Report. NEDU-1-89. Retrieved 2009-03-22.
6. Fundamentals of Environmental Measurement

External links

• Le Page, Michael (7 January 2006). "Breathing in oceans full of air". New Scientist (2533).(subscription required) History of attempts to develop artificial gills and the principles and problems involved.
• Bill Christensen (2005). "Breathe Like A Fish Thanks To Alan Bodner". Science Fiction in the News. Technovelgy.com. Archived from the original on 14 August 2007. Retrieved 2007-09-14.
• www.likeafish.biz Official website
• 'Like A Fish' Underwater Breathing System: Artificial Gills for U.S. Navy SEALs?
• Specific publication reference dates from an unusual source