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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Testing a new obstructive sleep apnoea (OSA) catheter for assessing airway collapse
Scientific title
Clarifying the location and mechanism of upper airway collapse in obstructive sleep apnoea: Testing of a multimodal manometry catheter
Secondary ID [1] 296660 0
TGA CTN number CT-2018-CTN-02515-1
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obstructive sleep apneoa 310495 0
Condition category
Condition code
Respiratory 309203 309203 0 0
Sleep apnoea

Study type
Description of intervention(s) / exposure
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.
Intervention code [1] 312967 0
Diagnosis / Prognosis
Comparator / control treatment
No control group, only known OSA patients will be used in this study
Control group

Primary outcome [1] 308175 0
Catheter based fibre optic pressure data (mmHg) to determine the location of the site(s) of collapse and the degree of occlusion that occurs during natural sleep
Timepoint [1] 308175 0
Recorded throughout the overnight sleep study
Primary outcome [2] 308207 0
Catheter based fibre optic temperature data (degrees C) to compare with external flow sensing in an attempt to infer flow and therefore the severity of reduced air flow due to airway obstruction during natural sleep.
Timepoint [2] 308207 0
Recorded throughout the overnight sleep study
Primary outcome [3] 308208 0
Catheter based micro camera video data to determine the anatomical features associated with and mechanism of collapse during natural sleep.
Timepoint [3] 308208 0
Recorded throughout the overnight sleep study
Secondary outcome [1] 354175 0
Catheter based bio-impedance pressure data to confirm fibre optic data for the location of the site(s) of obstruction, but to also define contact force of collapse during natural sleep.
(primary outcome)
Timepoint [1] 354175 0
Recorded throughout the overnight sleep study

Key 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
Minimum age
18 Years
Maximum age
65 Years
Both males and females
Can healthy volunteers participate?
Key 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

Study design
Purpose of the study
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 301239 0
Government body
Name [1] 301239 0
The National Health and Medical Research Council
Address [1] 301239 0
GPO Box 1421, Canberra, ACT 2601
Country [1] 301239 0
Primary sponsor type
Flinders University
Sturt Road, Bedford Park, SA 5042
Secondary sponsor category [1] 300878 0
Name [1] 300878 0
Address [1] 300878 0
Country [1] 300878 0
Other collaborator category [1] 280437 0
Commercial sector/Industry
Name [1] 280437 0
Trajan Scientific and Medical
Address [1] 280437 0
7 Argent Place, Ringwood, Victoria 3134
Country [1] 280437 0
Other collaborator category [2] 280438 0
Commercial sector/Industry
Name [2] 280438 0
Arkwright Technologies
Address [2] 280438 0
18 Devonshire Road, Hawthorndene SA 5051
Country [2] 280438 0

Ethics approval
Ethics application status
Ethics committee name [1] 301978 0
Southern Adelaide Clinical Human Research Ethics Committee
Ethics committee address [1] 301978 0
Office for Research, Flinders medical Centre, Flinders Drive, Bedford Park, SA 5042
Ethics committee country [1] 301978 0
Date submitted for ethics approval [1] 301978 0
Approval date [1] 301978 0
Ethics approval number [1] 301978 0
Ethics committee name [2] 301983 0
University of Western Australia Human Research Ethics Committee
Ethics committee address [2] 301983 0
Office of Research Enterprise, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009
Ethics committee country [2] 301983 0
Date submitted for ethics approval [2] 301983 0
Approval date [2] 301983 0
Ethics approval number [2] 301983 0

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.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 88746 0
Prof John Arkwright
Address 88746 0
Flinders University, Building T1, 1284 South Road, Tonsley, South Australia 5042
Country 88746 0
Phone 88746 0
+61 8 8201 2755
Fax 88746 0
Email 88746 0
Contact person for public queries
Name 88747 0
Prof John Arkwright
Address 88747 0
Flinders University, Building T1, 1284 South Road, Tonsley, South Australia 5042
Country 88747 0
Phone 88747 0
+61 8 8201 2755
Fax 88747 0
Email 88747 0
Contact person for scientific queries
Name 88748 0
Prof John Arkwright
Address 88748 0
Flinders University, Building T1, 1284 South Road, Tonsley, South Australia 5042
Country 88748 0
Phone 88748 0
+61 8 8201 2755
Fax 88748 0
Email 88748 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
Patient confidentiality
What supporting documents are/will be available?
No other documents available
Summary results
No Results