Dream come true: an Australian sleep-apnoea solution

From a bed of the softest titanium powder, 60 silvery air pipes emerge, perfectly formed by an electron-beam 3D printer. Each hollow harbinger of peaceful breathing is specifically shaped to fit the bite and feed the airways of one person suffering obstructive sleep apnoea (OSA).

This is the story of how Dr Christopher Hart, a sleep-deprived Australian dentist, collaborated with CSIRO, the nation’s innovation enabler, to lift the snorer’s curse for himself and for thousands, perhaps soon to be hundreds of thousands, of others.

Oventus
Anna Walsh, additive manufacturing technician at Oventus, uses extreme air to blow away residual titanium powder from individual O2Vents while they are still in the Arcam chamber. The powder is then collected for reuse. Photo courtesy Oventus.

Only 3D printing could simultaneously manufacture groups of such individual complex shapes as the O2Vent, a device described by its inventor as “a second nose” that overcomes the main causes of apnoeic obstruction: resistance in the nasal passages, soft-palate collapse and tongue collapse. And only a revolutionary software solution could eliminate costly individual design requirements, helping to make the product commercially viable. “The software is part of the CSIRO 3D platform technology; we customised it for the sleep-apnoea appliance,” says Stefan Gulizia, research group leader in additive manufacture of metals, and other related technologies at CSIRO.

“It enables a dentist to take the scan of a patient’s oral anatomy and overlay the device design, and stretch and manipulate it to fit,” says Gulizia. The dentist can then save the personalised device design as an STL file and send it to a 3D-printing facility.

In order to facilitate development of an advanced manufacturing industry in Australia, CSIRO has for three years operated Lab22 in Melbourne, which showcases the capabilities of several different kinds of 3D printers that use metal powders as their raw material. Two among its high-tech line-up—the Arcam electron-beam-melting (EBM) machine and Concept Laser printer—are made by companies in which GE recently acquired majority stakes as part of its commitment to additive manufacturing, which has the power to transform Australia’s manufacturing landscape.

“3D printing is perfect for Australia because it’s a low-volume, high-skill manufacturing technology that suits our educated nation,” says Gulizia.

The titanium air-pipe component of the O2Vent is polished by hand to a mirror-smooth surface, before it is incorporated into a soft-plastic mouthguard specifically moulded to the patient’s bite and palate shape. Photo courtesy Oventus.
And so, to bed …

Data from Europe and the US suggests that globally 17.4% of women and 34% of men between the ages of 30 and 70 years suffer from clinically significant OSA, which if untreated can contribute to their developing cardiovascular disease, diabetes, and to diminished quality of life and cognitive function. Underdiagnosed and undertreated, sleep apnoea causes millions of sufferers to wake, often hundreds of times a night as their airways become obstructed, CO2 levels in their bloodstream rise, and they snort briefly into wakefulness to restart breathing.

Hart, a severe apnoeic due to nasal obstruction, fashioned his first alternative-airway device out of plastic tubing in a moment of desperation. He couldn’t tolerate the most common and effective treatment for his condition: Continuous Positive Airway Pressure (CPAP), which requires sleeping with a bedside pump that forces air through a mask worn over the mouth and or nose to keep the airway open. Although highly effective, CPAP is an uncomfortable bedfellow for many sleep-apnoea sufferers, and the resulting low compliance is a barrier to successful long-term treatment.

When his concept of venting air to the back of the throat worked, Hart asked his then dental-lab technician, Michael Slater, who would become a co-founder of their medical-device company Oventus, to create a one-piece prototype out of moulded plastic. After six weeks of development, they had a bulky device that took 18 hours to make by hand.

When Hart was introduced by a patent lawyer to Neil Anderson, now MD and CEO of Oventus, Anderson immediately saw the potential in that awkward piece of plastic. A biomaterial scientist with experience in bringing medical innovations to market, he identified 3D printing as a possible means to more commercially manufacturing Hart’s sleep-apnoea device. He suggested the CSIRO might help with prototyping.

Metal guru

Says Gulizia, “I was the CSIRO lead in additive manufacturing at the very start when Chris and Neil approached us.” Titanium was an obvious choice of material for Hart’s oral device. It’s strong: the walls of the current O2Vent are less than half a millimetre thick, yet the hollow structure can withstand bruxing—grinding or clenching of the human jaw—which can exert forces near 500 pounds per square inch (psi). Titanium is also biocompatible, meaning it doesn’t corrode in the body, and is unlikely to cause tissue reaction.

CSIRO identified Arcam as the technology best suited to manufacturing the Oventus device. “The fact that our builds in the Arcam are held at a much higher temperature [than in laser machines], and in a vacuum, gives more control over the structure,” says Gulizia. It allows pieces to be built on top of each other, producing dozens of different patient files in the same 3D build.

To create each layer in the build, the electron-beam technology heats the entire powder bed to an optimal process temperature specific to the material used, which means components produced by the EBM process are free from residual stresses and do not require further heat treating.

The first devices were delivered within 11 months of Hart and Anderson beginning discussions with CSIRO. In November 2014, the week after the O2Vent had been registered with the Therapeutic Goods Administration, Hart says, “I hired a doctor’s room for $30 an hour and started taking impressions and shaping devices.”

Patients registered interest in the thousands every time the CSIRO put out a press release, or when Hart did a media interview. He says there was “a big bottleneck, because it was only me and a few of my mates doing it.”

When the CSIRO’s ability to print O2Vents on its Arcam A1 was outstripped by demand, Oventus sent STL files to New Zealand, Germany and the US for manufacture.

Dr Afshin Hosseini
Dr Afshin Hosseini, additive manufacturing supervisor at Oventus’ production facility in Clayton Victoria. He says, “Oventus bought this Q10 machine which is only the second Arcam machine in Australia. I had the experience of working with Arcam technology at the CSIRO, so I was the best candidate to start the production for them, without any waste of time.” Photo courtesy Oventus.
Ramping up production

In 2015, Oventus raised private capital to set up a manufacturing facility next door to Lab22. It hired Dr Afshin Hosseini, who completed his PhD in 3D printing using Arcam EBM technology at CSIRO, to be its additive manufacturing supervisor, plumbed in its new Arcam Q10 (which has since received an upgrade to Q10plus) and true commercial production began. “We can get to about 10,000 units a year using this machine,” says Hart.

The Q10plus is designed for efficient manufacture of orthopedic implants. “Our EBM process is much faster than a laser process as we can move the beam at 8,000 metres per second,” says Anders Thelander, director of area sales of Arcam EBM. He adds, “There are approximately 80,000 people worldwide who have implants in their bodies made by our EBM tech.”

Measures of success

The latest O2Vent is a hollow oval titanium duckbill and air channel hugging the upper gums  to the back of the mouth, nestled in a soft, medical-grade, plastic mouthguard. Recent studies of average wearing times show compliance for CPAP at 3.5 hours a night; for O2Vent it’s 6.1 hours a night. Efficacy is measured as the reduction in the number of times airflow is reduced, oxygen levels fall and the number of resulting micro waking events: “In our first trial, we found that 76% of patients had a 50% improvement in the number of events they suffered,” says Hart. Trials of the more refined current device found “that all patients had a positive response, and the number of events dropped by 78%—which is pretty profound.”

“By putting the airway into the device we almost have a pressure inlet valve, so if resistance increases in the nose or there’s a soft-palate obstruction, the air can continue to flow through the device airway,” explains O2Vent inventor Dr Chris Hart. Photo courtesy Oventus.

Soon airflow, air pressure, the wearer’s body position and whether the device is being worn or not will be monitored by sensors embedded in O2Vent devices, with data transmitted via Bluetooth to the cloud. Hart estimates that 80% of patients will get good results using the oral device.

For those who still require CPAP, Oventus Medical recently received a $3 million government Cooperative Research Centres (CRC) grant to develop miniaturised and maskless CPAP. Oventus will take the lead in collaborative research with CSIRO and NeuRA (Neuroscience Research Australia) on hybrid devices and on efficacy monitoring and the development of algorithms for treatment success.

Gulizia says the ongoing relationship with Oventus is a poster child for how the CSIRO can help to grow Australian business using innovative approaches, materials and manufacturing methods.

Hart is thrilled to be offering large numbers of apnoeics the means to simply, comfortably and effectively manage their sleep and their snoring, and ultimately extend their longevity. “The responses from patients are just phenomenal,” says Hart. “It’s very hard to get the devices off people just to make an adjustment! They want to wear it. They feel better. They’re not snoring. They’re getting better sleep. And they have more energy.”

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