Apnea Hypopnea Index Severity Versus Head Position During Sleep

Study Overview
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Brief Summary
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This study evaluates the correlation of the position of the head during sleep, independent of the position of the torso, and the severity of apnea hypopneas in obstructive sleep apnea.

Detailed Description
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Obstructive Sleep Apnea (OSA) is a common diagnosis in the general population, with a prevalence in the United States of 3-7% in men and 2-5% in women. It is defined as a sleep-related breathing disorder that results in decreased or complete cessation of airflow while the patient has ongoing breathing effort. It is well documented that trunk position significantly affects the severity of OSA. In fact, 50-75% of individuals with a diagnosis of OSA show supine predominance or worsened apnea-hypopnea index (AHI) when sleeping in the supine position. Positional Obstructive Sleep Apnea (POSA) is defined as an AHI ≥5 with >50% AHI reduction between the supine and non-supine positions and AHI. Studies show 49.5% of individuals with mild OSA (AHI 5-15), 19.4% with moderate OSA (AHI 15-30) and 6.5% in severe OSA (AHI > 30) had POSA. Due to this high prevalence of POSA, especially in the mild and moderate OSA populations, positional therapies have been developed and researched. In this clinical trial, if only the head position is considered, all subjects are positional sensitive and OSA severity can be calculated and consistently minimized by limiting the allowable range of head roll angle during sleep. Ten subjects underwent a standard polysomnography with an additional head angle sensor and coached to fall asleep in various head positions. Torso position was changed between supine and non-supine for a given head roll angle epoch to show the OSA severity change with torso position. Each sleep epoch of unique head pitch and roll angle was scored individually for AHI and Oxygen Saturation (SPO2) de-saturation. Investigators hypothesize that specific head roll angles independent of torso position will significantly reduce AHI and SpO2 desaturation severity in patients. The primary aim is to determine the head roll angles that significantly improve POSA independent of torso position. By doing this, Investigators believe to identify a safe zone of head roll angles that improve POSA and that can be used to support the development of head positional therapy for POSA patients.

Official Title
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The Effect of Head Pitch and Roll Rotation Independent of Torso Rotation on the AHI in Positional Obstructive Sleep Apnea

Conditions
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Sleep Disordered Breathing, Sleep Hypopnea, Sleep Apnea, Sleep Apnea, Obstructive, Snoring

Intervention / Treatment
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* Device: Dual-axis inclinometer attached to the subject's forehead with tape


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participant has provided written informed consent Participant is diagnosed with Positional Obstructive Sleep Apnea Participant age is between 21 and 60 years If currently on Positive Air Pressure (PAP) therapy, is able to produce compliance data within the last week before screening visit Is able to follow directions during the overnight sleep study If currently on PAP therapy participant self-report that excessive daytime sleepiness persists when PAP therapy is not in use Able to be of PAP therapy for 4 nights Exclusion Criteria: Documented diagnosis of Insomnia Chronic ear infections Persistent neck pains Persistent chronic posture physical issues Previous C-Spine fusion History of Cardiac Arrythmia History of seizures Allergic to Standard Tape used in Sleep Centers Non-English speaking. Hospitalization within the previous 4 weeks Use of antibiotics or steroids within the previous 4 weeks Any major uncontrolled disease or condition, such as congestive heart failure, malignancy, end-stage heart disease, end-stage heart disease. Arterial Laterial Sclerosis (ALS), or sever stroke, or other condition as deemed appropriate by investigator as determined by review of medical history and/or participant reported medical history History of severe osteoporosis Excessive alcohol intake (> 6oz hard liquor, 48 oz beer or 20 oz wine daily), or illicit drug use by review of medical history and/or participant reported medical history Daily use of prescribed narcotics (greater than 30 mg morphine equivalent)

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Forehead sensor recording precision head pitch and roll angle<br>During an overnight polysomnography, participants were coached by sleep research technologists to sleep with their head in positions hypothesized to minimize apnea severity ≤20⁰ or ≥160⁰, and those hypothesized to maximize apnea severity between 30⁰ and 150⁰. Head roll angles were measured and recorded by the participant's forehead sensor attached with adhesive and tape. Extreme head positions were attempted with the torso in both supine and non-supine positions so show insensitivity to torso position. A custom interface was developed to maintain compatibility with specific bedside polysomnography recorder auxiliary inputs. Sleep epochs were considered those where the subject slept for at least 10 minutes. Each head position epoch was analyzed for apnea hypopnea index and oxygen desaturation. | Device: Dual-axis inclinometer attached to the subject's forehead with tape<br>* This is the first clinical trial in the industry to address OSA symptom severity and snoring as a direct function of head pitch and roll angle. The head pitch and roll angle can be used with high consistency to predict OSA symptom severity. The apnea equation is based on the gravitational crush forces of the mass of the tongue and nearby tissue on the upper air way and is valid for most OSA sufferers.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Apnea Hypopnea Index (AHI) Severity Improvement | Investigators will perform a standard polysomnography with the addition of a precision forehead mounted angular sensor and monitor the severity of apnea hypopnea index (AHI) for the total time duration spent sleeping in each head position. The key measurement is the subjects' relative improvement in AHI with the head supine (45⁰ to 135⁰) as compared to non-supine (<20⁰above the horizon) | 8 hour polysomnography study with subjects being assessed at each head pitch and roll angle epoch | 
| Number of Participants With SpO2 Desaturation Severity Improvement | Investigators will perform a standard polysomnography with the addition of a precision forehead mounted angular sensor and monitor the severity of SpO2 desaturation for the total time duration spent sleeping in each head position. The key measurement is the subjects' relative improvement in SpO2 de-saturation with the head supine (45⁰ to 135⁰) as compared to non-supine (<20⁰above the horizon) | 8 hour polysomnography study with subjects being assessed at each head pitch and roll angle epoch | 
| Number of Participants With Improvement Independent of Torso Using Forehead Mounted Pitch and Roll Angle Sensor | Investigators will perform a standard polysomnography with the addition of a precision forehead mounted angular sensor and monitor the severity of apnea hypopnea index (AHI) as subjects sleep with the torso in the supine position while the head is ≤ 20⁰ and with the torso in the non-supine position while the head is above 45 degrees. The key measurement is the subjects' relative improvement in AHI with the head supine (45⁰ to 135⁰) as compared to non-supine (<20⁰above the horizon) independent of torso position | 8 hour polysomnography study with subjects being assessed at each head pitch and roll angle epoch | 
| Torso Independent With SpO2 Improvement Using Forehead Mounted Pitch and Roll Angle Sensor | Investigators will perform a standard polysomnography with the addition of a precision forehead mounted angular sensor and monitor the severity of SpO2 desaturation as subjects sleep with the torso in the supine position while the head is ≤ 20⁰ and with the torso in the non-supine position while the head is above 45 degrees. The key measurement is the subjects' relative improvement in SpO2 desaturation with the head supine (45⁰ to 135⁰) as compared to non-supine (<20⁰above the horizon) independent of torso position | 8 hour polysomnography study with subjects being assessed at each head pitch and roll angle epoch |