Ok let's have a discussion about High Pressure Nervious Syndrome "HPNS". I read in posting somewhere around here, stating that HPNS is brought on by the use of He at extreme depths, 400+FSW.
When I took the IANTD course the book I read stated that at first it was thought that He caused HPNS, however, recent research theorizes that HPNS is brought on due to the rapid onset of pressure.
The book stated that divers could reach depths below 1000+FSW on He02 if the pressure was increased slowly. This means a slow decent.
It was believed that when Sheck Exley and Jim Bowden dove Zacaton in 93 that Sheck died from HPNS. Not suprising, the dive plan put them at 1080FFW in 12 minutes. Sheck died at 800+FFW and Jim made it to 926FFW before calling it quits and returning to the surface. Now it is believed that Sheck died from C02 rather than HPNS. "Who knows"...
My point is that I believe that HPNS is brought on by rapid onset of pressure not by He.
Any views on this subject would be great.
Thanks again.
When I took the IANTD course the book I read stated that at first it was thought that He caused HPNS, however, recent research theorizes that HPNS is brought on due to the rapid onset of pressure.
The book stated that divers could reach depths below 1000+FSW on He02 if the pressure was increased slowly. This means a slow decent.
It was believed that when Sheck Exley and Jim Bowden dove Zacaton in 93 that Sheck died from HPNS. Not suprising, the dive plan put them at 1080FFW in 12 minutes. Sheck died at 800+FFW and Jim made it to 926FFW before calling it quits and returning to the surface. Now it is believed that Sheck died from C02 rather than HPNS. "Who knows"...
My point is that I believe that HPNS is brought on by rapid onset of pressure not by He.
Any views on this subject would be great.
Thanks again.