Sleep Apnoea Implants: Inspire & Nyxoah Genio

Treating Sleep Apnoea with Implants

Many people find it challenging to use CPAP (Continuous Positive Airway Pressure — a mask worn during sleep that delivers pressurised air to keep the airway open) or Mandibular Advancement Devices (MADs — custom-fitted gum shields designed to pull the lower jaw forward and open the airway behind the tongue) for treating obstructive sleep apnoea (OSA). Studies consistently show that CPAP compliance rates can be as low as 50–60%, with many patients discontinuing use within the first year due to discomfort, mask leaks, bloating, claustrophobia, or simply the inconvenience of travelling with the equipment. While MADs are generally better tolerated, they still cause problems in a significant number of patients, including jaw pain (temporomandibular joint dysfunction), dry mouth, excessive salivation, and gradual loosening of teeth with prolonged use. For some people, neither option is manageable long term.

Untreated sleep apnoea carries serious consequences. It is associated with a substantially increased risk of cardiovascular disease, including high blood pressure, heart attacks, and strokes. It also exacerbates metabolic conditions such as type 2 diabetes and contributes to weight gain, partly by disrupting the hormones that regulate appetite. The repeated overnight drops in blood oxygen — sometimes happening more than thirty times per hour — cause fragmented sleep, leaving patients excessively tired during the day, cognitively impaired, and at significantly higher risk of road traffic accidents. Chronic untreated OSA also has a well-documented impact on mental health, contributing to depression, anxiety, and mood instability.

Given these challenges and risks, hypoglossal nerve implants, such as the Inspire Hypoglossal Nerve Stimulator and the Nyxoah Genio System, offer a genuinely meaningful alternative for patients who have tried and failed conventional therapies. These devices address the underlying anatomical cause of airway obstruction during sleep — collapse of the tongue and soft tissue into the airway — rather than simply forcing the airway open with pressure. By stimulating the hypoglossal nerve to keep the upper airway musculature active during sleep, they can produce lasting improvements in sleep quality and overall health without any nightly equipment to fit, clean, or maintain.

Different Implants

Inspire Hypoglossal Nerve Stimulator Implantation

The Inspire Hypoglossal Nerve Implant is a fully implantable device for patients with obstructive sleep apnoea (OSA) who cannot tolerate CPAP. It delivers gentle electrical stimulation to the hypoglossal nerve, which controls the muscles of the tongue and upper airway, keeping the airway open throughout the night. The system has three components — a pulse generator in the chest, a breathing sensor lead, and a stimulation electrode near the jaw — all controlled by a small handheld remote. Over 125,000 patients worldwide have now been treated with Inspire, supported by more than 350 published studies.

The system is operated through a small, user-friendly handheld remote, allowing patients to turn the device on before bed and off upon waking. This minimally invasive treatment has been shown to significantly reduce the frequency of apnoea events, improve overall sleep quality, and enhance quality of life. NICE has issued specific guidance on its use in the UK (IPG598 and NG202), and NHS specialised commissioning now reimburses the system costs for eligible patients through the Specialised Services Device Programme.

Genio Hypoglossal Nerve Stimulator Implantation

The Nyxoah Genio System is an innovative treatment for moderate to severe obstructive sleep apnoea (OSA). What sets it apart from other implants is its design: it is battery-free, leadless, and requires only a single small incision under the chin. The entire implant sits beneath the chin, directly over the hypoglossal nerve, with no wires running through the chest or neck. Instead, the device is powered each night by an external activation chip held in place with a simple adhesive patch.

Unlike Inspire, which uses unilateral (one-sided) stimulation, the Genio system provides bilateral (both-sided) stimulation of the hypoglossal nerve, which some consider a physiological advantage. The system is MRI compatible and can be upgraded or recalibrated without further surgery to the implant itself, making it a flexible, forward-looking solution for OSA patients.

How the Inspire Implant Works

The Inspire Hypoglossal Nerve Stimulator is a fully implantable device designed to treat obstructive sleep apnoea. It consists of three main components: a pulse generator, a breathing sensor lead, and a stimulation electrode.

The pulse generator is implanted just beneath the skin in the upper right chest. A 5 cm incision is made just below the collar bone over the second rib, and the generator — less than 1 cm thick — is placed on top of the pectoralis muscle beneath the fat and skin. It is comparable in size and placement to a cardiac pacemaker and is rarely visible through the skin unless a patient has very low body fat. The battery within the generator is designed to last approximately eleven years, after which it is replaced in a minor outpatient procedure involving the chest only.

A breathing sensor lead runs from the pulse generator and is positioned between the muscles of the second and third ribs. This lead monitors the patient's respiratory cycle in real time, detecting the effort of each breath and relaying that information to the generator's internal computer. This means the device delivers stimulation only when it is needed — synchronised precisely with each attempt to inhale, when the airway is most at risk of collapsing.

A second lead also runs from the generator, travelling up through the neck to a second incision (again approximately 5 cm) made beneath the right side of the jaw. Here, the stimulation electrode is looped around specific branches of the hypoglossal nerve — specifically those that drive the tongue forward (the genioglossus and geniohyoid muscles) while deliberately avoiding the branches that cause tongue retraction. The electrode is also positioned close to the C1 nerve, stimulation of which helps prevent the epiglottis from obstructing the airway.

When the patient is ready to sleep, they activate the device using a small handheld remote. There is a built-in delay of around thirty minutes before stimulation begins, giving the patient time to fall asleep without being aware of any sensation. The device then works throughout the night by monitoring the breathing rhythm via the sensor lead. With each detected inhale, it delivers a gentle pulse to the hypoglossal nerve, prompting the tongue and surrounding muscles to move slightly forward. This prevents the tongue from falling back and blocking the airway — which is the fundamental mechanism behind OSA.

The stimulation is synchronised with the patient's breathing cycle. If the patient needs to get up in the night, a pause function allows the device to be temporarily suspended for fifteen minutes. In the morning, the patient simply turns the device off with the remote. The surgery itself is performed under general anaesthetic and takes approximately two hours. Most patients are discharged the same day, though an overnight stay is sometimes recommended. The device remains inactive for the first four to six weeks while the incisions heal.

How the Nyxoah Genio Implant Works

The Nyxoah Genio System is a pioneering fully implantable device designed to treat moderate to severe obstructive sleep apnoea. It is fundamentally different in architecture to the Inspire system. Rather than housing a battery and processor in the chest with leads running to the neck, the entire implant is a compact, leadless device positioned under the skin beneath the chin through a single small incision. There is no battery in the implanted component itself, no internal power source to run out, and no wires to be repositioned. The image below has been reproduced from the BLASTOSA trial (Eastwood PR, Barnes M, MacKay SG, et al. Bilateral hypoglossal nerve stimulation for treatment of adult obstructive sleep apnoea. Eur Respir J 2020;55), which provides a clear view of how the device sits in relation to the hypoglossal nerves on both sides of the tongue.

Each night before sleep, the patient applies the external activation chip to their skin, directly over the implanted stimulator, held in place with a simple adhesive patch. This external chip wirelessly powers the implanted stimulator and governs the delivery of mild, regular electrical pulses to both branches of the hypoglossal nerve simultaneously — what is known as bilateral stimulation. This causes the tongue and related airway muscles to move gently forward throughout the night, keeping the airway open and preventing the collapse that typically triggers apnoea events.

One practical advantage of the bilateral approach is that it does not require the patient to sleep in a specific position to maintain efficacy. The device operates continuously throughout the night, in rhythm with the patient's natural breathing, without requiring any sensing of the respiratory cycle. Upon waking, the patient removes the adhesive chip, stopping the stimulation entirely. There are no implanted batteries to deplete and no chest scars. The system is MRI compatible and can be recalibrated or upgraded through adjustments to the external chip rather than requiring further surgery to the implant itself.

What to Expect After Surgery: The Recovery Timeline

Both the Inspire and Genio procedures are performed under general anaesthetic, typically as day-case surgery, meaning most patients go home the same day. The surgical incisions are small and the implants sit just beneath the skin, so there is no significant disruption to the chest muscles or neck structures.

In the first few days after surgery, patients can expect mild to moderate pain and some swelling around the incision sites. Over-the-counter pain relief is usually adequate after the first couple of days. Strenuous activity, particularly any exercise involving the upper body and neck, should be avoided for approximately four weeks. Most patients can return to light daily activity within a few days.

The devices are not switched on immediately. There is a deliberate healing period of four to six weeks to allow the tissue around the implant to settle and the incision sites to fully heal. During this time, regular sleep is unaffected — the device simply lies dormant. At approximately four to six weeks, you will attend an outpatient appointment for the device to be activated and programmed with initial settings. For the Inspire, a small programmer is used to confirm the device is functioning correctly and to test tongue movement. You will be given the handheld remote and taught how to use it, and stimulation is started at a low level, which you gradually increase over the following weeks at home.

At around two to three months, a titration sleep study is performed. This is a standard overnight sleep study during which the device is adjusted to identify the optimal settings for controlling your sleep apnoea. Subsequent outpatient appointments monitor your progress and allow further fine-tuning. Most patients find they achieve a comfortable and effective stimulation level within the first few months, and benefit is typically maintained long term.

A chest X-ray is performed before discharge to confirm correct placement of the device and to rule out any lung complications. A short course of antibiotics is standard to minimise infection risk. Nerve-related side effects, such as temporary tongue weakness or altered sensation, are uncommon and usually resolve within days to weeks. Permanent complications are rare when the procedure is performed by an experienced implanting surgeon.

Eligibility for the Inspire Implant

• Moderate to severe obstructive sleep apnoea (OSA): an Apnoea-Hypopnoea Index (AHI) of 15–65. The AHI measures the number of times per hour a person stops breathing completely (apnoea) or has a significant reduction in breathing (hypopnoea) during sleep.
• PAP non-adherence or intolerance: patients who cannot tolerate Positive Airway Pressure therapy, fail to achieve consistent benefit from it, or decline its use. This non-adherence should ideally be documented by a healthcare provider.
• BMI of 35 or below: patients with a BMI above 35 are generally not suitable candidates, as excess soft tissue in the neck reduces the effectiveness of nerve stimulation. Weight loss may bring some patients back within the eligible range.
• Fewer than 25% central sleep apnoea events: central sleep apnoea occurs when the brain fails to send the correct signals to the breathing muscles. This is distinct from OSA, which is caused by physical airway obstruction. If more than 25% of events are central in origin, the implant is unlikely to help.
• Other sleep disorders excluded or treated: conditions such as Restless Legs Syndrome, Periodic Limb Movements, narcolepsy, and significant insomnia should either be ruled out or adequately managed before implantation, as they may affect the results or confound the assessment of the device's benefit.
• Drug-Induced Sleep Endoscopy (DISE): this procedure is required before Inspire implantation. The patient is lightly sedated and a flexible telescope is passed into the airway to observe how and where the airway collapses during simulated sleep. Patients with a specific pattern of collapse called 'complete concentric collapse' at the level of the soft palate are not suitable for Inspire, as the device is unlikely to prevent this type of obstruction. Around 80–85% of patients assessed with DISE prove suitable.
• No other active implantable medical devices: the Inspire system is not suitable for patients with cardiac pacemakers, defibrillators, or other active implantable devices, due to the potential for electromagnetic interference between the systems.

Eligibility for the Nyxoah Genio Implant

• Moderate to severe OSA: an Apnoea-Hypopnoea Index (AHI) of 15–65.
• PAP non-adherence or intolerance, documented or patient-reported.
• BMI of 35 or below.
• Fewer than 25% central sleep apnoea events.
• Other sleep disorders excluded or treated.
• No other active implantable medical devices: as with Inspire, the Genio system should not be used in patients with pacemakers or other electromagnetic implants.

One key practical difference between the two implants is the requirement for Drug-Induced Sleep Endoscopy (DISE). The Inspire implant requires DISE before proceeding, as the type of airway collapse pattern determines suitability. The Nyxoah Genio implant does not currently require DISE as part of the standard assessment pathway, because its bilateral stimulation approach is less dependent on the specific collapse pattern. This can simplify the pre-surgical workup for some patients, though a full clinical assessment remains essential for both devices.

Professor Veer's Role in Implant Surgery

Professor Vik Veer has been at the forefront of introducing hypoglossal nerve stimulation implants in the UK. He has performed more of these procedures than any other ENT surgeon in the country, and is actively involved in the design and development of a next-generation implant that aims to eliminate the need for surgical insertion entirely.

He was also involved in setting up the hypoglossal nerve stimulation programme at the Royal National ENT Hospital.

Enquire About Implant Treatment

Frequently Asked Questions

Will I feel the stimulation during the night?

Most patients are not consciously aware of the stimulation once they are asleep. When the device is first activated, you may notice a gentle tingling or mild tongue movement when lying still. There is a deliberate delay of around thirty minutes built into both devices before stimulation begins, giving you time to fall asleep. The stimulation level is increased gradually over the first few weeks so that your body adjusts to it. The aim is for the sensation to be sub-threshold during sleep — present but not disruptive.

Can I have an MRI scan once I have an implant?

The current Inspire model (3028) is MRI-conditional, meaning full-body MRI scans can be performed provided specific institutional guidelines are followed. This implant is currently not available in the UK — in the UK you are currently not allowed an MRI with the Inspire device. You would need to inform the radiologist or MRI team that you have an implanted device and carry your Inspire identification card. The Nyxoah Genio system is MRI compatible including in the UK. It is important to discuss any planned imaging with your surgeon before booking an MRI.

Can I travel by air or go through airport security?

Yes. Both devices are safe for air travel. It is possible that the metal detector at airport security will be triggered, so you should inform security staff that you have an implanted medical device and carry your device identification card. The devices themselves are not affected by standard airport security equipment.

What happens when the Inspire battery runs out?

The Inspire battery is designed to last approximately eleven years. When the charge is running low, the device provides a warning. Battery replacement is a minor outpatient procedure involving only the chest component; the leads and neck electrode do not need to be disturbed.

Can I use the device if I sleep on my back?

Both devices function regardless of sleep position. However, the DREAM trial for the Nyxoah Genio did require participants to be able to sleep in the supine (back) position for at least 60 minutes, which was a study inclusion criterion rather than a device limitation. In clinical practice, both implants are used by patients who sleep in various positions.

Is the treatment available on the NHS?

The Inspire and Genio systems are now available on the NHS through specialised commissioning, with NICE guidance (IPG598 and NG202) supporting its use. NHS provision is expanding across the UK, though access may depend on your local Integrated Care Board. Both systems are also available through private practice. A private consultation will allow us to assess your individual circumstances and advise on the most appropriate route to treatment.

Research Articles for the Inspire Implant

The STAR Trial — Strollo et al. (NEJM 2014)

The paper "Upper Airway Stimulation for Obstructive Sleep Apnea" by Strollo et al., published in the New England Journal of Medicine in 2014, evaluates the clinical safety and effectiveness of upper-airway stimulation using the Inspire Upper Airway Stimulation (UAS) system.

• Effectiveness: The study demonstrated a substantial reduction in the Apnoea-Hypopnoea Index (AHI) and Oxygen Desaturation Index (ODI). The median AHI decreased by 68%, from 29.3 events per hour to 9.0 events per hour. The ODI decreased by 70%, from 25.4 events per hour to 7.4 events per hour.
• Quality of Life: Secondary outcome measures including the Epworth Sleepiness Scale and the Functional Outcomes of Sleep Questionnaire (FOSQ) showed significant improvements in daytime sleepiness and overall quality of life, maintained at 24, 36, 48, and 60 months of follow-up.
• Long-term durability: The five-year follow-up (Woodson et al. 2018) reported that 75% of patients maintained a surgical response (AHI reduced by more than 50% and below 20 events per hour), and soft or no snoring was reported by 85% of bed partners.
• Safety and device reliability: The device has proved safe in large-scale real-world use. A 2024 post-market surveillance study of 5,820 implants found a one-year explant rate of only 0.723% and a revision rate of 1.54%, consistent with the clinical trial data.
• Implications: The STAR Trial established hypoglossal nerve stimulation as a proven alternative for patients who are unable to tolerate CPAP. Since the trial was published, more than 125,000 patients worldwide have been implanted with the Inspire system, and over 350 peer-reviewed publications have examined its use.

2024 Systematic Review and Meta-analysis (Respiratory Medicine)

A comprehensive meta-analysis published in October 2024 (Respiratory Medicine, Elsevier) reviewed 30 clinical trials involving 867 patients and provides the most up-to-date evidence on the long-term effectiveness of hypoglossal nerve stimulation devices.

• The Inspire device reduced AHI by an average of 20.14 events per hour in the short term (under twelve months) and 15.91 events per hour in the long term (over twelve months).
• The Oxygen Desaturation Index (ODI) fell by 14.16 events per hour in the short term and 12.95 events per hour in the long term.
• Patient-reported sleepiness, as measured by the Epworth Sleepiness Scale, improved by 5.02 points in the short term and 4.90 points in the long term — a clinically meaningful reduction.
• FOSQ scores improved by 3.58 in the short term and 3.28 in the long term, reflecting genuine improvements in daily functioning.
• The surgical success rate using standard Sher criteria (AHI reduction of more than 50% and AHI below 20 events per hour) was 69% at six months and 93.5% at twelve months, reflecting how the device's effect consolidates over time as settings are optimised.

Kim et al. Meta-analysis (Otolaryngology, December 2023)

Hypoglossal Nerve Stimulation Effects on Obstructive Sleep Apnoea Over Time: A Systematic Review and Meta-analysis. Published December 2023 · D. Kim, Otolaryngology — Head and Neck Surgery.

This meta-analysis pooled data from 44 studies involving 8,670 patients — the largest analysis of its kind at the time of publication — and evaluated outcomes at 12 and 36 months.

• At 12 months: 47% of patients had an AHI below 5 (effectively normal breathing), 72% had an AHI below 10 (mild at most), and 82% had an AHI below 15.
• Clinical success by Sher criteria: 80% within the first 12 months and 73% between 12 and 36 months.
• Effects stabilised between 12 and 36 months, indicating durable long-term benefit rather than progressive decline.

Conclusion: Hypoglossal nerve stimulation can meaningfully improve sleep-disordered breathing and quality of life for patients with obstructive sleep apnoea. The weight of evidence from over 44 studies and nearly 9,000 patients demonstrates a strong and durable response. While the biggest improvements occur in the first year — reflecting the period of device optimisation — outcomes remain stable thereafter.

Research Articles for the Nyxoah Genio Implant

BLASTOSA Study — Eastwood et al. (2020)

Bilateral Hypoglossal Nerve Stimulation for Treatment of Adult Obstructive Sleep Apnoea. The study by Eastwood et al. explored the effectiveness and safety of the Genio system in a prospective, open-label, single-arm trial conducted across eight centres in Australia, France, and the UK. Twenty-seven participants were enrolled, 22 of whom completed the study through to the six-month follow-up point.

• The AHI reduced from a mean of 23.7 events per hour at baseline to 12.9 events per hour at six months. The ODI fell from 19.1 to 9.8 events per hour over the same period. These represent clinically significant reductions in OSA severity.
• Quality of life improved substantially. The Epworth Sleepiness Scale showed meaningful reductions in daytime sleepiness, and the Functional Outcomes of Sleep Questionnaire (FOSQ-10) showed improved sleep-related quality of life.
• Adherence was high: 91% of participants used the device on more than five nights per week, and 77% for more than five hours per night. No serious device-related adverse events were reported during the study.

The Genio system's results in this early study are broadly comparable with other hypoglossal nerve stimulation systems, but with a simpler implant (no leads, no internal battery) and a straightforward stimulation algorithm. The authors concluded it offers a less invasive option with a promising safety and adherence profile.

Conclusion: The BLASTOSA study concluded that bilateral hypoglossal nerve stimulation using the Genio system effectively reduces OSA severity and improves quality of life without significant device-related complications. It represents a viable, less invasive alternative for patients who cannot use conventional therapies, offering high adherence and a good safety record in this early cohort.

DREAM Trial — IDE Pivotal Study for the Nyxoah Genio Implant

The DREAM Trial was a prospective, open-label, multicentre pivotal study designed to assess the safety and performance of the bilateral hypoglossal nerve stimulation (HGNS) system in adults with moderate to severe OSA. One hundred and fifteen participants were enrolled across multiple international centres.

Participants had to meet specific criteria to be included: an AHI of 15 to 65, the ability to sleep in the supine position for at least 60 minutes during baseline and 12-month polysomnography studies, and standard HNS eligibility criteria (CPAP intolerance, BMI 35 or below, fewer than 25% central events). The mean baseline AHI was 28.0 events per hour, ODI 27.0 events per hour, and BMI 28.5 kg/m².

At twelve months:

• The responder rate was 63.5% for AHI and 71.3% for ODI, using standard Sher criteria (at least 50% reduction in AHI and AHI below 20 events per hour).
• The median reduction in AHI from baseline was 70.8%.
• Compliance was high, with 85% of participants adhering to nightly use.
• There were 11 serious adverse events among 10 subjects (SAE rate 8.7%), of which three were device-related, resulting in device removal in three cases (device-related SAE rate 2.6%).

The DREAM Trial demonstrates that bilateral hypoglossal nerve stimulation with the Genio system can significantly reduce OSA severity and improve quality of life, with a high compliance rate and an acceptable safety profile.

Comparison of the DREAM Nyxoah Study and the Strollo STAR Inspire Study

Study Design and Participants

• The DREAM Trial evaluated the Genio bilateral hypoglossal nerve stimulation system in 115 participants across multiple centres in Australia, France, and the UK. Participants had moderate-to-severe OSA (AHI 15–65) and were CPAP intolerant.
• The Strollo STAR Inspire Study assessed the Inspire Upper Airway Stimulation system in 126 participants across 22 leading medical institutions in the United States and Europe. These participants also had moderate-to-severe OSA and had difficulties with CPAP therapy.

Effectiveness

• The DREAM Trial showed a reduction in AHI from 28.0 to 12.9 events per hour and ODI from 27.0 to 9.8 events per hour at 12 months. The responder rates were 63.5% for AHI and 71.3% for ODI.
• The Strollo STAR Inspire Study reported a 78% reduction in AHI and an 80% reduction in ODI at 12 months. The median AHI decreased from 29.3 to 9.0 events per hour, and the median ODI decreased from 25.4 to 7.4 events per hour.

Quality of Life Improvements

• In the DREAM Trial, the Epworth Sleepiness Scale score improved from a mean of 12.5 to 5.8, and the FOSQ-10 score increased from 14.7 to 19.6.
• In the Strollo STAR Inspire Study, the Epworth Sleepiness Scale score improved from a mean of 11.6 to 6.0. The FOSQ score increased from 14.4 to 18.9.

Adherence and Safety

• In the DREAM Trial, 85% of participants used the device regularly. The device-related serious adverse event rate was 2.6%, with device removal required in three cases.
• In the Strollo STAR Inspire Study, adherence was similarly high, with a serious complication rate of under 2%. Benefits were maintained at 36 and 60 months of follow-up.

Practical Summary

Both studies demonstrate meaningful and durable reductions in OSA severity and improvements in quality of life. The STAR Inspire Study reports somewhat stronger raw AHI reductions, reflecting the more mature optimisation protocols and the unilateral stimulation approach that targets specific tongue-protrusion nerve branches. The DREAM Genio Trial reports slightly lower responder rates but uses a simpler implant architecture and bilateral stimulation without a breathing sensor. Both therapies represent a significant step forward for patients who cannot tolerate CPAP, and the choice between them depends on individual anatomy, lifestyle, and clinical assessment.

Get in Touch

If you would like to know more, please use the links on this page to understand better what the treatment options for these conditions are.

If you would like more information please contact Prof Vik Veer via his team of secretaries:

Private secretary: 0207 458 4584
Email: secretary@consultant-surgeon.co.uk