oxtox {scuba}

Pulmonary Oxygen Toxicity

Description

Computes pulmonary oxygen toxicity dose for a given dive profile and breathing gas.

Usage

  oxtox(d, progressive=FALSE, warn=TRUE)

Arguments

d

The dive profile. An object of class "dive".

progressive

Logical flag. If FALSE, the total oxygen toxicity from the dive is calculated. If TRUE, the cumulative oxygen toxicity at each time point during the dive is calculated.

warn

Logical flag indicating whether to issue a warning if the partial pressure of oxygen exceeds a threshold (1.4, 1.5 or 1.6 ata).

Details

Computes the total dose of pulmonary oxygen toxicity from the given dive profile, by

\int_0^T \left( \frac{\mbox{ppO}_2 - 0.5}{0.5} \right)^{0.83} \; dt

The maximum tolerable dose per day is usually reckoned as 1500 OTU. Allowing 650 OTU for recompression therapy implies a working maximum of 850 OTU per day.

Value

If progressive=FALSE, a single numeric value, the total pulmonary oxygen toxicity dose in OTU.

If progressive=TRUE, a numeric vector containing the cumulative pulmonary oxygen toxicity dose in OTU at each time point during the dive. The corresponding time points can be extracted by times.dive.

Warnings

Not applicable to altitude dives.

Author(s)

Adrian Baddeley [e-mail].

References

Bookspan, J. (1995) Diving physiology in plain English. Undersea and Hyperbaric Medicine Society, Kensington, Maryland (USA). ISBN 0-930406-13-3.

Brubakk, A.O. and Neuman, T.S. (eds.) (2003) Bennett and Elliott's Physiology and Medicine of Diving. 5th Edition. Saunders. ISBN 0-7020-2571-2

Buehlmann, A.A., Voellm, E.B. and Nussberger, P. (2002) Tauchmedizin. 5e Auflage. Springer-Verlag.

Wienke, B.R. (1994) Basic diving physics and applications. Best Publishing Co.

See Also

ppO2, ead, eadtable, mod, maxmix

Examples

  # Nitrox II (36% oxygen) at 30 metres for 27 minutes
  d <- dive(nitrox(0.36), c(30,27))
  oxtox(d)

  # Same as above, followed by safety stop on 100% oxygen 
  d <- dive(nitrox(0.36), c(30,27),5, nitrox(1), c(5,5))
  oxtox(d)