Artificial gills (human)
{{Short description|Hypothetical devices to extract oxygen from water}}
{{Use dmy dates|date=June 2024}}
Artificial gills are hypothetical devices to allow a human to be able to take in oxygen from surrounding water. This is speculative technology that has not yet been demonstrated. Natural gills work because most animals with gills are thermoconformers (cold-blooded), so they need much less oxygen than a thermoregulator (warm-blood) of the same size. However, there are exceptions, for example, Opah, Great White Shark and Tuna. It is currently unclear if a practical artificial gill could be created; however, creating a biological gill with genetic engineering is theoretically possible.
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.{{cite journal |vauthors=Landé AJ, Claff CL, Sonstegard L, Roberts R, Perry C, Lillehei CW |title=An extracorporeal artificial gill utilizing liquid fluorocarbon |journal=Fed. Proc. |volume=29 |issue=5 |pages=1805–8 |year=1970 |pmid=5466244 }}{{cite journal |author=Landé, AJ |title=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 |journal=Undersea and Hyperbaric Medicine (Annual Meeting Abstract) |year=2006 |url=http://archive.rubicon-foundation.org/3675 |archive-url=https://archive.today/20130415204220/http://archive.rubicon-foundation.org/3675 |url-status=usurped |archive-date=15 April 2013 |access-date=2009-03-22 }}{{dubious|reason=Disolved oxygen content of water is the limiting factor as referenced below. |date=December 2017}} It is thought that a system such as this would allow for diving without risk of decompression sickness.{{cite journal |author=Landé, AJ |title=Artificial gill complements liquid breathing for diving to great depths, without being threatened by the bends |journal=Undersea and Hyperbaric Medicine (Annual Meeting Abstract) |year=2006 |url=http://archive.rubicon-foundation.org/3674 |archive-url=https://archive.today/20130415172032/http://archive.rubicon-foundation.org/3674 |url-status=usurped |archive-date=15 April 2013 |access-date=2009-03-22 }}
An average freediver needs 150ml of oxygen per minute while resting and 200-250ml of oxygen while swimming. Assuming the mammalian diving reflex, some divers can reduce their heartbeat significantly, down to 14 bpm, radically reducing overall body oxygen demands even down to 100ml per minute. The amount of dissolved oxygen in water varies, but on average is 7.6mg per liter. At least {{convert|37.5|L|USgal|1|sp=us}} of seawater per minute would have to be passed through the system, but this system would not work in anoxic water. Seawater in tropical regions with abundant plant life contains {{convert|6|–|8|mg|abbr=on}} of oxygen per liter of water.[http://www.fondriest.com/environmental-measurements/parameters/water-quality/dissolved-oxygen/ Fundamentals of Environmental Measurement] These calculations are based on the dissolved oxygen content of water.
See also
{{portal|Underwater diving}}
- Extracorporeal membrane oxygenation
- {{annotated link|Henry's law}}
References
{{Reflist}}
External links
- {{Cite journal |url=https://www.newscientist.com/article/mg18925331.300 |journal=New Scientist |title=Breathing in oceans full of air |date=7 January 2006 |first=Michael |last=Le Page |issue=2533}}{{subscription required}} History of attempts to develop artificial gills and the principles and problems involved.
- {{Cite web|url=http://www.technovelgy.com/ct/Science-Fiction-News.asp?NewsNum=397|title=Breathe Like A Fish Thanks To Alan Bodner|access-date=2007-09-14|publisher=Technovelgy.com|year=2005|author=Bill Christensen|work=Science Fiction in the News| archive-url= https://web.archive.org/web/20070814125818/http://www.technovelgy.com/ct/Science-Fiction-News.asp?NewsNum=397| archive-date= 14 August 2007 | url-status= live}}
- {{Official website|https://web.archive.org/web/20071013095535/http://likeafish.biz:80/|www.likeafish.biz official website}}
- [http://www.defensereview.com/like-a-fish-underwater-breathing-system-artificial-gills-for-us-navy-seals/ 'Like A Fish' Underwater Breathing System: Artificial Gills for U.S. Navy SEALs?]
- [http://mindmistress.comicgenesis.com/tidalw17.htm Specific publication reference dates from an unusual source]
- [https://www.gutenberg.org/files/19258/19258.txt Artificial gills in fiction] (called a "hydrolung") in Tom Swift and the Electronic Hydrolung, by Victor Appleton. It is a rebreather, fitted with a device that extracts oxygen from surrounding water.
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Category:Underwater diving medicine