Sleep Treatments | Sleep Review
Thanks to new technology, devices with positive airway pressure for sleep apnea fit even more easily on a bedside table or in a suitcase. But they do not necessarily fit into the lifestyle and habits of all users.
From Kristen Fischer
As smaller positive airway pressure devices hit the market, innovations in these highly travel-friendly CPAPs could pave the way to improve the therapy category as a whole.
“Consumers are looking for convenience and comfort,” said Ed McCarthy, director of business development at Somnera, which received FDA approval in 2020 for its positive airway pressure system. “Consumers are very interested in small, effective, and easy-to-use options.”
The size of the device doesn’t offer any medical benefit, but some patients may find a smaller device more convenient, McCarthy says.
Chelsie Rohrscheib, PhD, senior sleep specialist and neuroscientist at Tatch, who is developing a patch to detect sleep apnea, has also seen a trend towards making smaller CPAP machines.
Smaller CPAPs: Pros and Cons
Compact devices are generally more portable, which makes them popular with frequent travelers. And these devices have other advantages as well.
Some have slimmer, more flexible hoses that can make some people more comfortable to use, says Rohrscheib, adding, “A smaller machine means less cleaning and maintenance.”
However, sleep doctor Jamison Spencer, DMD, MS, organizer of the Spencer Study Club mentoring group, cautions that while smaller devices can make CPAP more portable, the smaller profile doesn’t tend to make CPAP therapy more acceptable. “Those who cannot tolerate a full-size CPAP may find themselves in the same situation with a smaller version,” says Spencer. He treats sleep apnea patients who cannot use CPAP by adapting them for oral devices.
And some models of small CPAPs have disadvantages, at least for patients who want to use them as a normal device for the night. For example, they tend to be more expensive than their full size counterparts, notes Rohrscheib, and those that rely on battery power need to be charged before use.
She also notes that some models of small CPAPs did not fine-tune their pressure variance and algorithm responsiveness as did larger devices. Tube washer says, “This means you may need a higher pressure setting for your mini CPAP to be effective.”
Michelle Worley, RN, director of clinical operations at Aeroflow Sleep, a long-life medical device supplier, says many devices designed primarily for travel do not contain humidification, a feature that can improve comfort.
“Just because the machine is smaller doesn’t mean it’s better, ”says Worley. “Of course, these smaller devices meet the same pressure requirements to qualify as CPAP as the larger devices, but they should only be used for travel.”
Even so, smaller CPAPs can be great for travel, says Worley. “Patients who travel frequently find it easier to pack a smaller CPAP machine into the pack,” she says.
Greg Dench, senior director, PAP devices at ResMed, a sleep and respiratory diagnostic and therapy company, says comfort – not just device size – is key to improving patient adherence and ultimately improving health outcomes.
“The better a device fits into a patient’s lifestyle, the more likely they are to adopt it, stick to treatment, and therefore improve their apnea symptoms and general health, ”says Dench.
There are several constraints that affect how small a device can be, including airflow needs, McCarthy says. CPAP machines create positive airway pressure by continuously pushing air through a closed system. When a user breathes against the airflow, it creates back pressure that “splinted” the airways so they stay open all night, he says.
“The air flow is provided by a fan that has to deliver a maximum of 150 liters of air per minute,” he says. “This requirement limits the size of the fan and thus the size of the CPAP device.”
The fan also needs insulation to keep it quiet enough to allow sleep, another size limitation. For devices with traditional water-based humidification, the humidifier also adds volume.
Newer, smaller devices
Somnera’s airbox device is 5.25 inches wide, 3.5 inches deep, and ~ 2.5 inches high, eliminating the need for a continuous flow of air to create the positive airway pressure required to effectively treat sleep apnea, says McCarthy. But it’s not made to replace CPAP.
“Somnera is ideal for a newly diagnosed patient who prefers the low airflow breathing experience or a current CPAP user who is having difficulty tolerating CPAP and is looking for a different experience,” he says.
The Somnera Airbox offers the same positive airway pressure as CPAP via a valve that is located right next to the airway in the user interface. The valve is charged with about 75% less airflow than a traditional CPAP machine, resulting in a cyclical breathing experience, he says. When inhaling, the user sucks air out of the room through the valve, combined with a supportive airflow from the airbox. When exhaling, the patient creates counter pressure through their own exertion of breathing by breathing against the valve in order to achieve the therapeutic pressure at the end of each breath.
“It is important to note that unlike CPAP, the user does not experience airflow from the device when they exhale,” says McCarthy.
By creating positive airway pressure while drastically reducing airflow requirements, the company can downsize many device components, such as the hose.
The ResMed AirMini is another small device that weighs less than a pound. There are three modes: CPAP, AutoSet, and AutoSet for Her. It has a waterless humidification system that provides the convenience of moisture without having to take distilled water everywhere.
The AirMini works with a wide range of ResMed AirFit and AirTouch masks and has ResMed’s proven algorithms, Dench says. Patients can control the settings on a smartphone, where they can track their sleep.
Since it was launched a few years ago, Dench says, the company has had positive feedback on device size and convenience – especially because it doesn’t require water.
The Philips Dreamstation 2 is another popular small profile CPAP device. It has the company’s smallest tube diameter and is compatible with the Philips DreamMapper mobile sleep apnea app and the Philips Care Orchestrator for the clinician. The company also makes DreamStation Go, a travel device.
Businesses are always on the lookout for innovation, especially as the bulkiness of some patients makes it difficult to use the beneficial CPAP technology.
From a hardware perspective, advances in fan design have the potential to radically impact the footprint of CPAP machines, McCarthy says. He adds, “From a software perspective [artificial intelligence] will have a major impact on further refining the algorithms that drive the devices by making them more accurate in identifying and preventing events, which will improve the therapy of these devices. “
Kristen Fischer is a New York based copywriter, journalist, and author.
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