None listed
Conditions
Brief summary
The project aims to characterise airway collapse in obstructive sleep apnoea (OSA) by utilising a multimodal catheter during a sleep study normally used for OSA diagnosis. Traditionally diagnosis would not readily identify the reason for obstruction and current methods of simulating airway collapse are often not comparable to that of natural sleep. This study aims to increase our understanding of the mechanisms of airway collapse during natural sleep of OSA patients with a view to improved targeting of subsequent therapeutic interventions. It is considered that a simple method to establish the primary site and mechanism for upper airway collapse during naturally occurring sleep would improve the ability of clinicians to distinguish which patients would benefit from a variety of treatments available. By introducing a newly developed manometry catheter into sleep studies of 15 known OSA sufferers we expect to be able to determine the location of the site(s) of collapse, the degree of occlusion that occurs, the severity of reduced air flow, the anatomical features associated with and mechanism of collapse. The device has the ability to record pressure, temperature, contact force and visualisation of the point of collapse.
Interventions
This study will be a polysomnography (sleep study) conducted in a sleep laboratory. Participants will be prepared with standard monitoring devices used within typical sleep studies including the following:
* Electroencephalogram (EEG) – electrodes placed on the scalp for determination of sleep macro-architecture (total sleep time, time in Stage N1, N2, N3, and REM sleep, and sleep efficiency), and sleep micro-architecture (sleep onsets, arousals and awakenings).
* Eye movements (EOG) – electrod
This study will be a polysomnography (sleep study) conducted in a sleep laboratory. Participants will be prepared with standard monitoring devices used within typical sleep studies including the following: * Electroencephalogram (EEG) – electrodes placed on the scalp for determination of sleep macro-architecture (total sleep time, time in Stage N1, N2, N3, and REM sleep, and sleep efficiency), and sleep micro-architecture (sleep onsets, arousals and awakenings). * Eye movements (EOG) – electrodes placed 1cm diagonally below each eye for assessing sleep onset (slow rolling eye-movements) and rapid eye-movement (REM) sleep. * Electrocardiogram (ECG) – electrodes placed on right clavicle, and left 8th intercostal space for determination of heart rate changes. * Chin/jaw and leg electromyogram (EMG) – electrodes place on the mandible and on the shins of the legs for assessing sleep stages (particularly muscle hypotonia in REM) and periodic leg movements. * Finger pulse oximetry (SpO2%) for assessing oxygen desaturation events and peripheral vasoconstriction responses (changes in plethysmography signal). * Respiratory effort via respiratory inductance plethysmography (RIP) bands placed around the thorax and abdomen measure respiratory effort. The study will aim to record data for at least 6 hours of sleep and each stage of sleep. In addition to this monitoring equipment a multimodal catheter and calibrated airflow sensor will be used. The specialised multimodal catheter will be used to measure upper airway pressure and temperature whilst recording video evidence of airway collapse. The device has been developed by Alex Wall under the guidance of Prof. John Arkwright at Flinders University. Pressure and temperature measurements will be taken using fibre optic technology whilst bio-impedance will simultaneously provide corroboration of pressure and contact force. The catheter features a series of 13 equally spaced fibre optic pressure sensors mounted inside the lumen and 13 bio-impedance electrode rings span the catheter. A Medigus micro camera (around the size of a grain of rice) is mounted prior to the 13 sensors at the proximal end of the catheters sensing region with a single fibre optic sensor preceding the camera as a reference in the nasal cavity. The camera body and wire has been integrated within the catheter lumen to minimise the external protrusion and creating a flexible sealed unit. The catheter will be passed through a cable gland in the mask worn by the participant during a standard over-night sleep study. This allows for an airtight seal before being advanced through the most patent nostril following nasal decongestion and topical anaesthesia (Lidocaine Gel 2%). Once in place, the catheter will be taped at the nose and will only be repositioned when sites of obstruction are identified during the study. Two investigators will monitor and observe the over-night study from an adjoining room, whilst measurements and video records are logged. The catheter is a Class IIa medical device.
Sponsors
Flinders University
Study design
Allocation
Non-randomised trial
Primary purpose
Diagnosis
Eligibility
Sex/Gender
All
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Obstructive sleep apnoea patients * Body mass index (BMI) less than 35 kg/m2 * Apnoea hypopnoea index (AHI) greater than or equal to 20 /hr * No nasal congestion
Exclusion criteria
* Current smokers * History of cardiac, respiratory, craniofacial or metabolic disorders * Abnormal lung function (FEV1 or FVC < 80% predicted) * Other relevant co-morbidities or co-existing sleep disorders (e.g. periodic limb movement disorder) * Medications that may affect respiration * Moustaches or beards likely to cause air leaks with a nasal mask. * Adhesive, latex or any other allergy relevant to the study procedures
Outcome results
None listed