The HyPod– The Multiple-Use Hyperbaric Chamber.
As can be understood from the “Our History” section of this website, the concept of a light, portable, demountable hyperbaric chamber was first conceived in 1998 as a potential lifesaving apparatus for people suffering from decompression illnesses (“DCI” see section below ‘Decompression Illnesses’). Although other occupations can render the participant susceptible to DCIs, most who suffer this problem are sub-aqua divers who have surfaced to quickly from deep dives. And because it was conceived as a lifesaving aid for sub-aqua divers, it was initially marketed as the “DiveAlive Decompression Chamber”.
However, only in the past few years has the wide and diverse potential of the generic HyPod chamber been identified. That is, its ability to be the basic unit design of any number of situations where economic, light, portable compression chambers are needed (enclosed environments whose internal pressure and gas mixes can be fully monitored and controlled, irrespective of any external pressures, be it higher or lower). The most significant attribute of the HyPod is its ability to enable a multi-purpose treatment called ‘Hyperbaric Oxygen Therapy’ (“HBOT”).
To utilise as wider range as possible of HyPod’s multi-use potential, in addition to the original concept of providing treatment for DCIs, four more independent, but associated, enterprises have been created. Each of the additional four concerns has been provided with 99 year licence to exclusively exploit the patent on the generic unit for a particular market or industry. Now the five entities are:
- HyPod Ltd
This company specialises in the original concept for HyPod, being the provision of “Decompression Chambers” to treat DCIs (see section below ‘Decompression Illnesses’). It holds the patents and trademarks for HyPod and licences their specific use to the other four companies.
- HyPod Animal Care Ltd (ourselves)
We have an exclusive licence in regard to all veterinary matters worldwide, specialising in the provision of HBOT for animals – see the contents of this website.
- HyPod Medical Ltd
This company has an exclusive licence in regard to human health matters worldwide, specialising in human HBOT for all forms of medical treatments, surgical procedures and cosmetic aids.
- HyPod Humanitarian Ltd.
This company, together with its Charitable associates, has an exclusive licence to operate in a particular ‘compression’ centric business. ie. using higher than ambient pressures to aid in relief and rescue. The provision of multi-purpose, very lightweight, economic, portable ‘lifting’ devises for use in international disaster response.
- HyPod Habitats Ltd.
This company has an exclusive licence to operate in another particular ‘compression’ centric business, specialising in the manufacture and operation of human habitats which provide an internal living space at 1.5 to 3 bar, when the external pressure is either ambient or zero (for space exploration).
Decompression Illnesses – Generally referred to as ‘DCI’
Excludes any type of gas ‘Narcosis’ (Nitrogen Narcosis)
DCI is believed to result from two different mechanisms (conditions), where the symptoms of both can seem similar or overlapping. The two mechanisms are:
Decompression Sickness (‘DCS’), results from metabolically inert gas dissolved in body tissue under pressure precipitating out of solution and forming bubbles during any form of uncontrolled decompression (rapid reduction in air pressures outside/inside the body). It typically afflicts sub-aqua divers on poorly managed ascent from depth or aviators flying in inadequately pressurised aircraft.
Arterial Gas Embolism (‘AGE’), results from bubbles of gas forming in the bloodstream causing the blood to appear to ‘boil’. In the context of DCI these may form due to two mechanism ‘subsets’, being:
During prolonged exposure to higher than atmospheric pressures, significantly more molecules of various gases dissolve into the bloodstream. On rapid decompression these gases do not have time to gradually precipitate and vent out naturally through the lungs. ‘Nucleation’ is triggered (minute gas bubbles are ‘seeded’) and the gas bubbles grow in size and number.
Gas bubbles can directly enter the bloodstream in a ‘mechanical’ process as a result of pulmonary barotrauma, which is the rupturing of lung tissue. This rupturing is caused by rapid depressurisation of the air in the lungs (the normal breathing gases), resulting in an uncontrolled massive increase in its volume, too rapid to be naturally vent by ‘breathing out’.
Who is at risk of DCI ?
Any breathing entity (human or otherwise) that is exposed (by design or accident) to any environment that can undergo rapid and uncontrolled decompression. That is the rapid reduction of its ambient air pressure.
This is applicable to environments that might engender much higher pressures than normal atmospheric (1 Atmosphere or say 1 Bar) and then rapidly descend to normal atmospheric pressures (like sub-aqua diving).
Or environments that sustain normal atmospheric pressure but then accidently rapidly descend to virtually no pressure (like high flying pressurised aircraft that suddenly lose their cabin pressure).
Examples of causes of DCI
There are a number of diverse situations/occupations that run the risk of causing DCI. Possibly the first time the symptoms and problems were recognised it was in respect to workers operating under air pressures higher than atmospheric.
Like workmen excavating new tunnels in circumstances that were prone to the excavations flooding. Therefore the entrances had to be ‘sealable’ so that excavation could take place under pressure and thereby reduce water ingress (flooding). These operatives worked long shifts under pressure and before DCI was fully understood, they were decompressed very quickly when their shift ended, which caused many of them to initially suffer minor DCI symptoms. But in later life, their various body joints disintegrated and they became severely disabled because the fine blood capillaries in the bones of their joints could became blocked by small gas bubbles and thus normal blood flow was impaired. They were said to be suffering from “Tunneller’s Disease”. In 1966, the Home office issued warnings about such problems and provided strict working guidelines regarding decompression times.
Today the two most widely publicised causes of DCI are:
Sub-aqua divers or submariners ascending too quickly after periods of breathing high pressure air (like escaping from a damaged submarine or ascending from a deep dive). They can also suffer from a DCI if they don’t ‘breathe out’ regularly on the accent. They might not even ‘breath in’ on the accent because the air in their lungs continually expands as its ambient pressure decreases, due to there being less and less ‘water over them’.
Technical Note: a liquid like water cannot itself be pressurized, no matter what ‘pressure’ is exerted on it. So its density/volume is a constant, it never varies. However, the deeper a diver goes, the more weight of water there is over them, so the more the ‘squeezing’ effect on any of their ‘cavities’, like lungs, sinuses or inner ears (or even a sealed empty bottle). That is to say, if the pressure on any ‘cavity’ is increased, its volume is reduced. For example, at 10 meters deep, the squeezing pressure is doubled (to 2 Atmospheres), so the total volume of a diver’s lungs at 10 meters is half the size that it would be at the surface.
For each any every 10 meters a diver submerges, the pressure increases by 1 Atmosphere (about 1 Bar). So at 100 meters the pressure is 10 Atmospheres and the divers lungs might have shrunk to the size of grapefruits ! When divers suffer a DCI, the popular expression is that they are suffering from “The Bends”.
The other widely published cause of DCI is the ‘explosive’ (extremely rapid) decompression of an aircraft cabin or other pressurised environment. Aircraft that are designed to fly at very high altitudes where the air pressure is extremely low, are usually pressurised to 11 or 12 psi (Pounds per Square Inch) to allow passengers to breath comfortably. Otherwise passengers would suffer like mountain climbers who can’t get enough oxygen into their lungs.
12 psi is about 85% of the pressure at sea-level, which is 1 Atmosphere being 14.6959 psi. (Whereas 1 Bar is 14.5038 psi, just slightly less than 1 Atmosphere)
When there is explosive decompression, crew and passengers can suffer DCI or quickly lose consciousness if they are not given oxygen masks to breathe from. Sometimes it’s only a matter of seconds before there is loss of coordination, followed by loss of consciousness and a number of private jets have crashed for this very reason. Today, it’s accepted convention that the pilot actually doing the flying of the aircraft, continuously wears an oxygen mask or at least has one very close to hand !
The close association of DCS and AGE
In any situation where decompression sickness is encountered, there is also potentially a risk of arterial gas embolism. Many of the obvious symptoms are so common to both conditions that it may be difficult to distinguish between the two without expert medical attention. Luckily in practice during real emergences, the initial first aid procedures are the same for both problems.
Signs and Symptoms of DCI
Following is a summary comparison of the signs and symptoms of DCI arising from its two components: Decompression Sickness and Arterial Gas Embolism. Many signs and symptoms are common to both maladies, and it may be difficult to diagnose the actual problem. The dive history can be useful to distinguish which is more probable, but it is possible for both components to manifest at the same time following some dive profiles.