Stewart spent $45,000 on a chamber for his wife Robin after she suffered a severe stroke five and a half years ago.
She had previously tried out other treatments, including a round of Etanercept injections in the United States but saw only slight improvements.
The first significant improvement Robin had was upon her return to New Zealand when she tried a round of oxygen therapy with Health Evolution, a private clinic in Paraparaumu.
After a month's worth of treatment, Ian made the decision to purchase his own chamber for Robin at their home, ordering a top of the line model from Korea. Since undergoing treatment in the oxygen chamber, a mild HBOT chamber which allows patients to inhale 27 per cent oxygen, Robin has regained some movement on her left side, her husband said.
"She's still got limited use of her left hand side but she is able to use that hand to do lots of things. Previously, it was useless."
As well as Robin using the chamber, the couple now had people coming around most days to use the chamber for conditions ranging from non-healing wounds, to depression or concussion.
A majority of these people paid a "modest" fee - from $60 to $80 per session. Many were referred to him by Health Evolution - the private clinic in Paraparaumu where the Stewarts were introduced to the treatment.
Stewart said it was disappointing the treatment was not publicly funded for a greater scope of medical ailments. When used in conjunction with other traditional medicines, he said it could be hugely beneficial for a range of conditions.
Dr Richard Medlicott, the Medical Director at the Royal New Zealand College of General Practitioners, said experience with HBOT at the GP level was limited, but he knew it had been "very successful" in alleviating various conditions.
"Healing requires oxygen, and sometimes for various reasons we just can't get enough oxygen to the tissues where it's needed," he said.
It was important to note HBOT wasn't a magic fix to any condition, but Medlicott said having a bit more information out in the public and in medical circles wouldn't go amiss.
"I think it's reasonable to say it would be good to have a little bit more awareness that it's out there."
In a statement provided to the Herald on Sunday, a Ministry of Health spokesperson said DHB-funded HBOT treatment was available to patients suffering conditions included on a list created by the Undersea and Hyperbaric Medical Society in the United States.
"If a condition is not listed in the UHMS treatment indications, it means that there isn't an internationally recognised evidence base of clinical benefit that is sufficient," they said.
Hayley Brown, of Health Evolution, said her clinic predominantly treated patients for concussions and traumatic brain injuries - two conditions for which HBOT was not accessible through ACC funding.
Health Evolution sold a range of hyperbaric chambers and had links with other private clinics or providers like Stewart, around the country.
Brown said some patients who could be referred for DHB-funded HBOT weren't being referred because of a lack of understanding in mainstream health services about the benefits of HBOT.
Health Evolution was involved in the opening of Te Kohao clinic in Hamilton, which was aiming to boost awareness within the Tainui people around the benefits of HBOT for those suffering ailments like diabetic ulcers.
Brown said HBOT could help patients suffering to avoid amputation.
Conditions hyperbaric oxygen treatment is funded for through Waitematā and Canterbury DHBs
• Decompression illness (DCI)
• Arterial gas embolism (AGE)
• Air or gas embolism
• Carbon monoxide (CO) poisoning
• Sudden acute hearing loss
• Clostridial myositis & myonecrosis (gas gangrene)
• Crush injuries
• Enhancement of healing in selected problem wounds
• Exceptional blood loss - anaemia
• Intracranial abscess
• Necrotising soft tissue infections
• Refractory osteomyelitis
• Hyperbaric treatment for complications of radiation therapy
• Skin grafts and flaps (compromised)
• Thermal burns
Source: Waitematā DHB website
