"Oxygen clock" vs "CNS clock"...when did that happen?

Hi all,

I've been doing a bit of research of late into the history of oxygen exposure management from a CNS and whole-body/pulmonary point of view. The different interpretations about the original NOAA oxygen exposure table are of particular interest.

But that is not what I want to discuss here. What I cannot ascertain is just at which point, did someone begin to call that table the "CNS clock"? In the NOAA manual it was called "oxygen clock" briefly and was mentioned with regard an unspecific "oxygen toxicity". In the recent (20) years, dive agencies have began to label this the "CNS clock" but I cannot find for certain who was first.

Does anybody know? Many thanks in advance.

CNS Clock was a term that Bill Hamilton despised, but it caught on.

I believe it was first used in the IANTD Nitrox manual around 1993 but contact Tom Mount or Michael Munduno directly.

You will not find the answer to your question there, but you may be interested to read through the proceedings of the DAN Nitrox Workshop held in November of 2000.

Doppler:

CNS Clock was a term that Bill Hamilton despised, but it caught on.

I believe it was first used in the IANTD Nitrox manual around 1993 but contact Tom Mount or Michael Munduno directly.

You will not find the answer to your question there, but you may be interested to read through the proceedings of the DAN Nitrox Workshop held in November of 2000.

Click to expand...

Very useful Steve thanks very much I have read through the DAN Nitrox Workshop proceedings and it contains some great stuff. I had heard before about Bill Hamilton's opinion of the phrase but thought it interesting in those proceedings that he didn't completely object against it:

B. Hamilton: NOAA exposure limits. I would put oxygen clock in quotes since that's only one way to express it.
M. Lang: Concept after that?
B. Hamilton: That's good, with the word concept there.
D. Kesling: Add a CNS component to that just to differentiate.
B. Hamilton: CNS oxygen clock.
R. Moon: There's a bit of a danger in putting that down there because that implies that there is awell established relationship between time of exposure and CNS O2 toxicity, which there is not. I'm not sure exactly what we're trying to impart by that bullet. I would say the opposite: Teach the fact that CNS O2 toxicity can be sudden and unexpected rather than predictable based upon time of exposure.
D. Kerem: I second that.
B. Hamilton: Michael, why don't you just add that on? CNS oxygen toxicity can occur suddenly and unexpectedly. I entirely agree with Richard Moon.


He even proposes "CNS oxygen clock" there though does follow up to say that its implication is not entirely accurate. Such a straight forward table with such colourful history :-D