Post by LSDeep on Nov 18, 2004 7:25:21 GMT -5
here something else - what tom mentioned to me during our hyperbaric conversation. its pretty weird too!
Respirocytes could serve as an in vivo SCUBA (Self-Contained Underwater Breathing Apparatus) device. With an augmentation dose or nanolung, the diver holds his breath for 0.2-4 hours, goes about his business underwater, then surfaces, hyperventilates for 6-12 minutes to recharge, and returns to work below. (Similar considerations apply in space exploration scenarios.)
Respirocytes can relieve the most dangerous hazard of deep sea diving -- decompression sickness ("the bends") or caisson disease, the formation of nitrogen bubbles in blood as a diver rises to the surface, from gas previously dissolved in the blood at higher pressure at greater depths. Safe decompression procedures normally require up to several hours. At full saturation, a human diver breathing pressurized air contains about ~(d - d0) x 1021 molecules N2, where d is diving depth in meters and d0 is the maximum safe diving depth for which decompression is not required, ~10 meters. A therapeutic dose of respirocytes reconfigured to absorb N2 instead of O2/CO2 could allow complete decompression of an N2-saturated human body from a depth of 26 meters (86 feet) in as little as 1 second, although in practice full relief will require ~60 sec approximating the circulation time of the blood. Each additional therapeutic dose relieves excess N2 accumulated from another 16 meters of depth. Since full saturation requires 6-24 hours at depth, normal decompression illness cases present tissues far from saturation, hence relief will normally be achieved with much smaller dosages. The same device can be used for temporary relief from nitrogen narcosis while diving, since N2 has an anesthetic effect beyond 100 feet of depth.
Direct water-breathing, even with the help of respirocytes, is problematic for several reasons: (1) Seawater contains at most one-thirtieth of the oxygen per lungful as air, so a person must breathe at least 30 times more lungfuls of water than air to absorb the same volume of respiratory oxygen; lungs full of water weigh nearly three times more than lungs full of air, so a person could hyperventilate water only about one-third as fast as the same volume of air. As a result, a water-breathing human can absorb at most 1%-10% of the oxygen needed to sustain life and physical activity. (2) Deep bodies of water may have low oxygen concentrations because oxygen is only slowly distributed by diffusion; in swamps or below the thermocline of lakes, circulation is poor and oxygen concentrations are low, a situation aggravated by the presence of any oxygen-consuming bottom dwellers or by oxidative processes involving bottom detritus, pollution, or algal growth. (3) Both the diving reflex and the presence of fluids in the larynx inhibit respiration and cause closure of the glottis, and inhaled waterborne microflora and microfauna such as protozoa, diatoms, dinoflagellates, zooplankton and larvae could establish (harmful) residence in lung tissue.
Respirocytes could serve as an in vivo SCUBA (Self-Contained Underwater Breathing Apparatus) device. With an augmentation dose or nanolung, the diver holds his breath for 0.2-4 hours, goes about his business underwater, then surfaces, hyperventilates for 6-12 minutes to recharge, and returns to work below. (Similar considerations apply in space exploration scenarios.)
Respirocytes can relieve the most dangerous hazard of deep sea diving -- decompression sickness ("the bends") or caisson disease, the formation of nitrogen bubbles in blood as a diver rises to the surface, from gas previously dissolved in the blood at higher pressure at greater depths. Safe decompression procedures normally require up to several hours. At full saturation, a human diver breathing pressurized air contains about ~(d - d0) x 1021 molecules N2, where d is diving depth in meters and d0 is the maximum safe diving depth for which decompression is not required, ~10 meters. A therapeutic dose of respirocytes reconfigured to absorb N2 instead of O2/CO2 could allow complete decompression of an N2-saturated human body from a depth of 26 meters (86 feet) in as little as 1 second, although in practice full relief will require ~60 sec approximating the circulation time of the blood. Each additional therapeutic dose relieves excess N2 accumulated from another 16 meters of depth. Since full saturation requires 6-24 hours at depth, normal decompression illness cases present tissues far from saturation, hence relief will normally be achieved with much smaller dosages. The same device can be used for temporary relief from nitrogen narcosis while diving, since N2 has an anesthetic effect beyond 100 feet of depth.
Direct water-breathing, even with the help of respirocytes, is problematic for several reasons: (1) Seawater contains at most one-thirtieth of the oxygen per lungful as air, so a person must breathe at least 30 times more lungfuls of water than air to absorb the same volume of respiratory oxygen; lungs full of water weigh nearly three times more than lungs full of air, so a person could hyperventilate water only about one-third as fast as the same volume of air. As a result, a water-breathing human can absorb at most 1%-10% of the oxygen needed to sustain life and physical activity. (2) Deep bodies of water may have low oxygen concentrations because oxygen is only slowly distributed by diffusion; in swamps or below the thermocline of lakes, circulation is poor and oxygen concentrations are low, a situation aggravated by the presence of any oxygen-consuming bottom dwellers or by oxidative processes involving bottom detritus, pollution, or algal growth. (3) Both the diving reflex and the presence of fluids in the larynx inhibit respiration and cause closure of the glottis, and inhaled waterborne microflora and microfauna such as protozoa, diatoms, dinoflagellates, zooplankton and larvae could establish (harmful) residence in lung tissue.
