assumed a 240-min controlling tissue. It involved step decompression over a 

 13-hr period and a normoxic N2-O2 mixture. This table had to be abandoned, 

 however, as both test subjects suffered an attack of bends in the first chamber 

 run. In the second test, air was used rather than the N2-O2 mixture, but once 

 more both subjects were "hit." 



The table was then recalculated based upon a 460-min Ti,, which extended the 

 decompression period to 15 hr. But the test results ol this schedule were 

 unsatisfactory. The decompression table was recalculated, this time based on 

 a Ti, of 500 min, which extended decompression to 19 hr, 20 min; once more the 

 results of testing were unsatisfactory. Periods of O2 breathing (4 hr, 25 min) 

 were then substituted for air-breathing periods, and the tests were finally 

 deemed satisfactory and the table adopted for use in TEKTITE I. 



Since decompression following TEKTITE I appeared to be uneventful, the same 

 decompression table was accepted for use in the TEKTITE II 50-ft missions. 

 But because of the evidence of dysbarism described in "Medical Program," this 

 volume, the table was altered to include 70 minutes of additional O2 breathing, 

 although the entire schedule was increased only by 60 min (see Appendices A 

 and B) . 



If the results of decompressing the aquanauts in TEKTITE II were to be used as 

 a basis for calculation, the ultimate table for decompression from a habitat 

 pressure of 40 FSW (the actual habitat pressure) would be based on a slowest 

 Tj- of well over 1000 minutes! 



Decompression From 100 FSW 



The calculation and testing of decompression tables to be used in bringing the 

 TEKTITE II Minitat aquanauts safely back to surface from their habitat pressure 

 of 100 FSW presented a new challenge in saturation diving. A normoxic breathing 

 mixture was planned for these missions: an oxygen partial pressure of 160 mm Hg 

 with a nitrogen diluent. Each mission was to last 14 days, meaning that the 

 aquanauts ' bodily tissues would become saturated with the nitrogen partial 

 pressure of their breathing mixture. 



The Marine Biomedical Institute of the University of Texas Medical School 

 (Galveston) undertook the preliminary development of the 100-FSW decompression 

 tables through a contract with the J&J Marine Diving Co., Pasadena, Tex. 

 Peter Edel of that organization (who had developed the emergency tables for 

 TEKTITE I) calculated the first table for the 100-FSW dives using a Tj, of 360 min 

 and Workman M-values. The result was a decompression schedule of 30-hr duration. 



In Test No. 1 it was decided, because of limited funds, not only to test the 

 proposed decompression tables but also the calculated maximum safe descent 

 excursion, to 175 FSW. An accelerated saturation (which began 15 Dec 1969) 

 of two subjects to the Minitat PN2 was accompl"lshed by first exposing 

 them to 137-FSW pressure for 12 hr in a 957=, N2-57o 0^ breathing mixture (a 

 technique developed by Edel for the TEKTITE I tests). After saturation, the 

 subjects were compressed to 175 FSW for 6 hr, where they breathed air; they 

 were then rapidly decompressed--within 3 min--to 100 FSW, at which pressure they 

 remained for 16 hr. Both subjects remained asymptomatic. One of them, however, 

 developed bends symptoms (L knee) during decompression to surface pressure, at 

 50 FSW, and required recompression therapy. 



IX-17 



