Uwatec Aladin Pro Nitrox Operating Manual page 15

2. The decompression model used by the Aladin
Nitrox considers nitrogen in both its dissolved as
well as its gaseous phase (microbubbles). Formati-
on of microbubbles is considered to be a strong
indicator of a high risk of decompression sickness.
®
The Aladin Pro Nitrox model calculates the
formation of microbubbles depending on various
assumed influences in arterial and venous blood.
In normal, slow ascents, microbubbles form mainly
in venous blood. During fast ascents, microbubbles
may also form in arterial blood and in the body's
tissues as well. If a particular dive profile may result
in the creation of microbubbles according to the
®
Aladin Pro Nitrox's model, decreased bottom time
and/or increased decompression times as well as
increased "no fly" time will be indicated.
• Microbubbles can form if the diver makes too fast
an ascent, ignores required decompression stops,
or makes repeated ascents during a dive (yo-yo
diving). These microbubbles can form in arterial
4 The Calculation Model ZH-L8 ADT
® Pro
8
blood as well as in the body's tissues. If these
microbubbles partially impair circulation, the rate
of gas diffusion and saturation tolerance for those
tissues immediately surrounding this area of
impaired circulation are changed. If required, both
decompression time and RBT will be adjusted in
such a way that already existing microbubbles will
stop growing. Increased decompression time will
also assist those local areas of impaired circulation
to desaturate with less risk of decompression
sickness.
• The calculation of microbubbles results in altered
ascent instructions. If microbubbles are assumed
to be present based on the data used by the Ala-
din ® Pro Nitrox, the ascent rate to the surface is
reduced to 7 metres/minute. This will help prevent
the formation of microbubbles in the arterial
circulation and minimizes formation of micro-
bubbles in the venous circulation after the dive.
I Introduction