Thermodynamic model of decompression

Thermodynamic model of decompression is a theoretical framework used to understand and predict the physiological effects of changes in pressure on a diver during ascent from depth. It is based on the principles of thermodynamics, a branch of physics that deals with heat and temperature and their relation to energy and work.

Overview

The thermodynamic model of decompression is used to calculate decompression schedules for divers to prevent decompression sickness, a potentially life-threatening condition caused by the formation of gas bubbles in the body's tissues and blood. This model is based on the principles of Henry's law, which states that the amount of gas that can be dissolved in a liquid is directly proportional to the pressure of the gas.

Principles

The thermodynamic model of decompression involves several key principles:

• Pressure reduction: As a diver ascends, the pressure decreases, which can cause dissolved gases in the body to come out of solution and form bubbles.
• Gas exchange: The body continuously absorbs and eliminates gases, a process that is affected by changes in pressure.
• Bubble formation and growth: If the pressure reduction is too rapid, bubbles can form and grow in the body's tissues and blood, leading to decompression sickness.

Decompression Schedules

Decompression schedules calculated using the thermodynamic model of decompression provide divers with a safe ascent profile, specifying the depths at which they should pause (decompression stops) and for how long, to allow the safe elimination of gases from the body.

Limitations

While the thermodynamic model of decompression is widely used, it has some limitations. It assumes that the body is a homogeneous system and that gas exchange is instantaneous, which is not the case. Furthermore, it does not account for individual variations in physiology or for the effects of factors such as temperature, exercise, or hydration status.

See Also

• Decompression theory
• Decompression practice
• Decompression sickness
• Henry's law