X-Message-Number: 21168 Date: Fri, 14 Feb 2003 13:06:17 +0100 From: Henri Kluytmans <> Subject: Respirocytes as in vivo SCUBA device Kennita Watson wrote : >Assume that *all* a respirocyte could do were to store >compressed oxygen and release it at a controlled rate. >Has anyone posited an estimate of how long an injection >(IV infusion, lungful, time-release capsule, skin patch, >whatever) of them would allow a person to breathe >underwater? Yes. Robert Freitas who created the design for these devices has also worked out such details. :) I quote : "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.)" His number for the maximum augmentation dose : "Infusion of 1 liter (~asymptomatic blood loss limit [97], ~plasma volume increase in high-altitude-adapted people [95], ~hemodilution limit for freshwater aspiration in the lungs [98], ~splenic capacity) of 50% respirocyte suspension raises total oxygen carrier volume to 55% of blood volume (RBC hct ~46% plus respirocrit ~9%), after absorption of water from the blood equal in volume to the infusion." So the short answer is : 4 hours with a 1 liter 50% dose. (And using these kind of artificial devices will even relieve decompression sickness or caisson disease from being a danger.) Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=21168