As we know, Helium gas is an inert gas that is less toxic than nitrogen at equal pressure. There is no evidence of any drug from helium. So it is more suitable for deep diving than for nitrogen. At high pressure, helium also causes hypertensive neurological syndrome, a CNS irritation syndrome that is anti-inflammatory.
The helium filling is usually ten times more than a similar gas filler. Uses similar air depths to estimate the decomposition requirements of a mixture of nitrox. Trimix uses a similar drug depth to estimate the drug potential. Many divers have found that the level of narcotics in a 30-meter dive is the maximum comfortable breathing level.
Why are Deep-Sea Divers Using Air Diluted With Helium Gas In Own Air Tanks?
Professional deep-sea divers carry a compressed air tank to breathe under high pressure. Normally compressed air contains nitrogen and oxygen, but these gases are not soluble in blood and other body fluids under normal pressure. Because the pressure at that depth is much higher than the surface atmospheric pressure, more nitrogen dissolves in the blood. And also other body fluids as the diver breathes through the tank.

As the diver climbs to the surface, the pressure decreases, dissolved nitrogen is releasing from the blood, and other body fluids quickly form bubbles in the bloodstream. These bubbles restrict blood flow and affect the transmission of nerve impulses. Especially, it can even rupture or block capillaries.
This condition is calling painful and life-threatening “bending.” The reason is the lower solubility of helium in the blood than nitrogen, and professional divers use air diluted with helium gas. In addition, small helium atoms can travel through cell walls without being damaged. Excess oxygen dissolved in the blood is using in metabolism. And does not cause bending.
The Function Of The Helium
The main cause for adding helium to the breathing mixture is to reduce the ratio of nitrogen and oxygen to the air, allowing the gas mixture to breathe safely on deep diving. A low percentage of nitrogen is required to minimize the nitrogenous drug and other physical effects of deep gas. Helium has a very low narcotic effect. A low percentage of oxygen reduces the risk of oxygen poisoning on deep dives. The low nature of helium reduces the resistance to deep breathing.
Breathing can limit the use of the breathing air mixture in underwater breathing apparatus. And with increasing depth, the breathing function may reach a point where it exceeds the effort available to the diver.
Accumulation of carbon dioxide beyond this point eventually results in severe and debilitating hypercapnia, which, if not corrected quickly, causes the diver to try to breathe faster and exacerbate breathing. It increases the risk of loss of consciousness and a high risk of drowning.

Disadvantages Of The Helium
Helium gas conducts heat six times faster than air, so helium inhalers often have a separate gas supply. Primarily, it is to prevent the risk of hypothermia by using helium as an inflator gas. The argon carries in a small separate tank connected only to the inductor in the drying set. It is more suitable for air as it conducts heat 50% faster than argon.
Dry clothes still require minimal inflation to prevent “squeezing” damage to the skin by applying pressure to dry clothes. Some divers suffer from hyperbaric arthralgia while descending, and Trimix helps with symptoms of compression.