Obstructive Sleep Apnoea (OSA)EPPOSANCT07406620
Entropy-based Physiological Signal Analysis in Patients With Obstructive Sleep Apnoea
An observational study of Obstructive Sleep Apnoea (OSA), run by King's College London at 2 sites in United Kingdom.
Trial summary
This observational study is being undertaken as a part of a Master of Research (MRes) in Clinical Research programme. Its goal is to learn about how continuous positive airway pressure (CPAP) therapy changes the complexity of body signals in adults with obstructive sleep apnoea (OSA). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Obstructive Sleep Apnoea (OSA)
- What is being tested?
- Continuous Positive Airway Pressure Therapy
- Type of treatment
- Medical device
- How many people
- 139 participants
- Where
- 2 sitesUnited Kingdom
- Study dates
- 11 Jun 2026to Sep 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: PAP-naive adults with obstructive sleep apnea (OSA), identified from the Sleep and Ventilation Service at Royal Free London NHS Foundation Trust, who participated in the 3DPiPPIn randomised controlled trial.
Who may be able to join
- Participation in the 3DPiPPIn trial
- Availability of physiological signal data at baseline and at least one follow-up time point (i.e. three months and/or six months post-CPAP)
- Provision of informed consent permitting the use of their data in future research
Who cannot join
- Non-participation in the 3DPiPPIn trial
- Absence of physiological signal data at both follow-up time points (i.e. no available data at either three months or six months post-CPAP)
- No consent for the use of their data in future research
Trial locations and contacts
2 sites in 1 country.
United Kingdom2 sites
Royal Free Hospital
London, NW2 2QG
King's College London
London, WC2R 2LS
About this study
Official title: Entropy-Based Assessment of Physiological Signals in Obstructive Sleep Apnoea Patients Pre and Post Continuous Positive Airway Pressure Therapy: A Secondary Analysis of 3DPiPPIn Trial Data
This observational study is being undertaken as a part of a Master of Research (MRes) in Clinical Research programme.
Its goal is to learn about how continuous positive airway pressure (CPAP) therapy changes the complexity of body signals in adults with obstructive sleep apnoea (OSA). The main question it aims to answer is:
Read more
- How does the complexity of physiological signals (specifically oxygen saturation, heart rate, and heart rate variability) change in adults with OSA from before to after three and six months of CPAP treatment?
It will use data from individuals who took part in an earlier trial, called 3DPiPPIn, which tested the use of 3D-printed, customised masks CPAP masks through sleep studies.
Read the detailed description
The purpose of this MRes student study is primarily to examine how the entropy, or complexity as measured by entropy, of physiological signals changes in patients with obstructive sleep apnoea (OSA) in response to continuous positive airway pressure (CPAP) therapy.
It is a secondary analysis of data from 3DPiPPIn, a randomised control trial investigating the feasibility of using 3D-printing to develop customised masks for patients receiving positive airway pressure (PAP) therapy.
The hypothesis for this study is that entropy-based measures derived from physiological signals will exhibit changes following CPAP therapy, when compared to pre-therapy measures, reflecting the modulation and restoration of physiological systems that were previously disrupted by OSA.
- Conditions
- Obstructive Sleep Apnoea (OSA)
- Being tested
- Continuous Positive Airway Pressure Therapy
- Keywords
- Obstructive Sleep Apnoea, OSA, Continous Positive Airway Pressure, CPAP, Entropy
- Medical subject headings
- Sleep Apnea, Obstructive
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Continuous Positive Airway Pressure TherapyDevice
Also called CPAP, CPAP Therapy, PAP, PAP Therapy
The intervention of interest within this secondary analysis study is Continuous Positive Airway Pressure (CPAP) Therapy, a device-based treatment used to maintain airway patency in patients with sleep-disordered breathing. As a retrospective study, participant exposure to CPAP occured exclusively within the original 3DPiPPIn trial.
| Study group | Role | What they receive |
|---|---|---|
| 3DPiPPIn Trial Participants | Participants were originally recruited to the 3DPiPPIn trial from the Sleep and Ventilation Service at Royal Free London NHS Foundation Trust. The cohort for this secondary analysis comprises adults with sleep-disordered breathing and an Apnoea-Hypopnoea Index (AHI) >15 events/hour who required but had never received PAP therapy, drawn from the trial participants who provided consent for their data to be used in future research. Receives: Device: Continuous Positive Airway Pressure Therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in oxygen saturation entropy from pre to six months post CPAP therapy
Measured: From baseline to six months post-initiation of CPAP therapy
Change in heart rate entropy from pre to six months post CPAP therapy
Measured: From baseline to six months post-initiation of CPAP therapy
Change in heart rate variability entropy from pre to six months post CPAP therapy
Measured: From baseline to six months post-initiation of CPAP therapy
Secondary outcomes (10)
Change in oxygen saturation entropy from pre to three months post CPAP therapy
Measured: From baseline to three months post-initiation of CPAP therapy
Change in heart rate entropy from pre to three months post CPAP therapy
Measured: From baseline to three months post-initiation of CPAP therapy
Change in heart rate variability entropy from pre to three months post CPAP therapy
Measured: From baseline to three months post-initiation of CPAP therapy
Relationship between residual Apnoea-Hypopnoea Index and oxygen saturation entropy
The Apnoea-Hypopnoea Index (AHI) is the total number of apnoea and hypopnoea events per hour of sleep. The minimum value is 0 events/hour, and there is no fixed maximum value. Higher scores indicate more severe sleep-disordered breathing (worse outcome).
Measured: From baseline to three and/or six months post-initiation of CPAP therapy
Relationship between residual Apnoea-Hypopnoea Index and heart rate entropy
The Apnoea-Hypopnoea Index (AHI) is the total number of apnoea and hypopnoea events per hour of sleep. The minimum value is 0 events/hour, and there is no fixed maximum value. Higher scores indicate more severe sleep-disordered breathing (worse outcome).
Measured: From baseline to three and/or six months post-initiation of CPAP therapy
Relationship between residual Apnoea-Hypopnoea Index and heart rate variability entropy
The Apnoea-Hypopnoea Index (AHI) is the total number of apnoea and hypopnoea events per hour of sleep. The minimum value is 0 events/hour, and there is no fixed maximum value. Higher scores indicate more severe sleep-disordered breathing (worse outcome).
Measured: From baseline to three and/or six months post-initiation of CPAP therapy
Relationship between Epworth Sleepiness Scale scores and oxygen saturation entropy
The Epworth Sleepiness Scale (ESS) is a self-administered questionnaire that measures daytime sleepiness. Scores range from 0 to 24, with higher scores indicating greater daytime sleepiness (worse outcome).
Measured: From baseline to three and/or six months post-initiation of CPAP therapy
Relationship between Epworth Sleepiness Scale scores and heart rate entropy
The Epworth Sleepiness Scale (ESS) is a self-administered questionnaire that measures daytime sleepiness. Scores range from 0 to 24, with higher scores indicating greater daytime sleepiness (worse outcome).
Measured: From baseline to three and/or six months post-initiation of CPAP therapy
Relationship between Epworth Sleepiness Scale scores and heart rate variability entropy
The Epworth Sleepiness Scale (ESS) is a self-administered questionnaire that measures daytime sleepiness. Scores range from 0 to 24, with higher scores indicating greater daytime sleepiness (worse outcome).
Measured: From baseline to three and/or six months post-initiation of CPAP therapy
Nocturnal hypoxia (T90%)
T90% will be calculated as the percentage of total sleep time during which oxygen saturation is below 90%. T90 values will be categorised according to predefined thresholds to characterise the severity of nocturnal hypoxia.
Measured: At baseline, three months and/or six months post-initiation of CPAP therapy
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Feb 2026
- Study start11 Jun 2026
- Primary completionAug 2026 (estimated)
- Study completionSep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for Obstructive Sleep Apnoea (OSA)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 139 participants (estimated)
Sponsor and investigators
- Lead sponsor
- King's College London
- Sponsor type
- University, hospital or other
- Collaborators
- Royal Free Hospital NHS Foundation Trust
- Responsible party
- Principal investigator, Ime Umoabasi, King's College London
- Investigators
- Izaak Neri, Study director, King's College LondonStephanie K Mansell, Study director, Royal Free London NHS Foundation Trust, University College London
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07406620
- Sponsor's protocol ID
- 366646
- Acronym
- EPPOSA
- Status last verified
- Aug 2026
- First submitted
- 29 Jan 2026
- Last updated
- 10 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: The data used in this secondary analysis include potentially re-identifiable patient information. In line with the open access approach of the study's parent trial, 3DPiPPIn, individual participant data will not be shared to protect participant confidentiality.
Publications
Shah AJ. The use of wearable technology in chronic respiratory disease. Doctor of Philosophy (PhD), University College London; 2025. Available from: https://discovery.ucl.ac.uk/id/eprint/10212804
Mansell SK, Mandal S, Ridout D, Olsen O, Gowing F, Kilbride C, Hilton ST, Main E, Schievano S. Clinical impact of customised positive airway pressure (PAP) therapy interfaces versus usual care in the treatment of patients with sleep-disordered breathing (3DPiPPIn): a randomised controlled trial protocol. BMJ Open. 2024 Nov 14;14(11):e087234. doi: 10.1136/bmjopen-2024-087234.
PubMed 39542493Mansell SK, Olsen O, Gowing F, Muwaffak Z, Kilbride C, Hilton S, Main E, Schievano S, Mandal S. 3DPiPPIN: 3D printing of positive airway pressure (PAP) therapy interfaces: a single site feasibility study. J Med Eng Technol. 2025 Oct;49(7):293-303. doi: 10.1080/03091902.2025.2532648. Epub 2025 Jul 29.
PubMed 40728908Mansell S, Olsen O, Smith L, Augustt S, Kilbride C, Ridout D, Hilton S, Main E, Schievano S, Mandal S. 3D Printing Positive Pressure Interfaces (3DPiPPIn): Results From a Two-Phase Feasibility Trial [Abstract]. Am J Respir Crit Care Med 2025;211:A6945. doi: 10.1164/ajrccm.2025.211.Abstracts.A6945
Study at a glance
From the registry record, last updated by the sponsor on 10 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Entropy-Based Assessment of Physiological Signals in Obstructive Sleep Apnoea Patients Pre and Post Continuous Positive Airway Pressure Therapy: A Secondary Analysis of 3DPiPPIn Trial Data
- ClinicalTrials.gov ID
- NCT07406620
- Acronym / sponsor ID
- EPPOSA / 366646
- Conditions
- Obstructive Sleep Apnoea (OSA)
- Keywords
- Obstructive Sleep Apnoea, OSA, Continous Positive Airway Pressure, CPAP, Entropy
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 139 participants (estimated)
- Lead sponsor
- King's College LondonUniversity, hospital or other
- Collaborators
- Royal Free Hospital NHS Foundation Trust
- Study start
- 11 Jun 2026 (actual)
- Primary completion
- Aug 2026 (estimated)
- Study completion
- Sep 2026 (estimated)
- First posted
- 12 Feb 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This observational study is being undertaken as a part of a Master of Research (MRes) in Clinical Research programme.
Its goal is to learn about how continuous positive airway pressure (CPAP) therapy changes the complexity of body signals in adults with obstructive sleep apnoea (OSA). The main question it aims to answer is:
- How does the complexity of physiological signals (specifically oxygen saturation, heart rate, and heart rate variability) change in adults with OSA from before to after three and six months of CPAP treatment?
It will use data from individuals who took part in an earlier trial, called 3DPiPPIn, which tested the use of 3D-printed, customised masks CPAP masks through sleep studies.
Detailed description
The purpose of this MRes student study is primarily to examine how the entropy, or complexity as measured by entropy, of physiological signals changes in patients with obstructive sleep apnoea (OSA) in response to continuous positive airway pressure (CPAP) therapy.
It is a secondary analysis of data from 3DPiPPIn, a randomised control trial investigating the feasibility of using 3D-printing to develop customised masks for patients receiving positive airway pressure (PAP) therapy.
The hypothesis for this study is that entropy-based measures derived from physiological signals will exhibit changes following CPAP therapy, when compared to pre-therapy measures, reflecting the modulation and restoration of physiological systems that were previously disrupted by OSA.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| 3DPiPPIn Trial Participants | – | Device: Continuous Positive Airway Pressure TherapyParticipants were originally recruited to the 3DPiPPIn trial from the Sleep and Ventilation Service at Royal Free London NHS Foundation Trust. The cohort for this secondary analysis comprises adults with sleep-disordered breathing and an Apnoea-Hypopnoea Index (AHI) >15 events/hour who required but had never received PAP therapy, drawn from the trial participants who provided consent for their data to be used in future research. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- PAP-naive adults with obstructive sleep apnea (OSA), identified from the Sleep and Ventilation Service at Royal Free London NHS Foundation Trust, who participated in the 3DPiPPIn randomised controlled trial.
Key inclusion criteria (3 listed)
- Participation in the 3DPiPPIn trial
- Availability of physiological signal data at baseline and at least one follow-up time point (i.e. three months and/or six months post-CPAP)
- Provision of informed consent permitting the use of their data in future research
Key exclusion criteria (3 listed)
- Non-participation in the 3DPiPPIn trial
- Absence of physiological signal data at both follow-up time points (i.e. no available data at either three months or six months post-CPAP)
- No consent for the use of their data in future research
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Continuous Positive Airway Pressure TherapyAlso: CPAP, CPAP Therapy, PAP, PAP TherapyThe intervention of interest within this secondary analysis study is Continuous Positive Airway Pressure (CPAP) Therapy, a device-based treatment used to maintain airway patency in patients with sleep-disordered breathing. As a retrospective study, participant exposure to CPAP occured exclusively within the original 3DPiPPIn trial. | Device | 3DPiPPIn Trial Participants |
Primary outcome
Change in oxygen saturation entropy from pre to six months post CPAP therapy
Time frame: From baseline to six months post-initiation of CPAP therapy
Change in heart rate entropy from pre to six months post CPAP therapy
Time frame: From baseline to six months post-initiation of CPAP therapy
Change in heart rate variability entropy from pre to six months post CPAP therapy
Time frame: From baseline to six months post-initiation of CPAP therapy
10 secondary outcomes
Change in oxygen saturation entropy from pre to three months post CPAP therapy
Time frame: From baseline to three months post-initiation of CPAP therapy
Change in heart rate entropy from pre to three months post CPAP therapy
Time frame: From baseline to three months post-initiation of CPAP therapy
Change in heart rate variability entropy from pre to three months post CPAP therapy
Time frame: From baseline to three months post-initiation of CPAP therapy
Relationship between residual Apnoea-Hypopnoea Index and oxygen saturation entropy
Time frame: From baseline to three and/or six months post-initiation of CPAP therapy
Relationship between residual Apnoea-Hypopnoea Index and heart rate entropy
Time frame: From baseline to three and/or six months post-initiation of CPAP therapy
Relationship between residual Apnoea-Hypopnoea Index and heart rate variability entropy
Time frame: From baseline to three and/or six months post-initiation of CPAP therapy
Relationship between Epworth Sleepiness Scale scores and oxygen saturation entropy
Time frame: From baseline to three and/or six months post-initiation of CPAP therapy
Relationship between Epworth Sleepiness Scale scores and heart rate entropy
Time frame: From baseline to three and/or six months post-initiation of CPAP therapy
Relationship between Epworth Sleepiness Scale scores and heart rate variability entropy
Time frame: From baseline to three and/or six months post-initiation of CPAP therapy
Nocturnal hypoxia (T90%)
Time frame: At baseline, three months and/or six months post-initiation of CPAP therapy
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Aug 2026.
- BackgroundShah AJ. The use of wearable technology in chronic respiratory disease. Doctor of Philosophy (PhD), University College London; 2025. Available from: https://discovery.ucl.ac.uk/id/eprint/10212804
- Background: PubMed 39542493Mansell SK, Mandal S, Ridout D, Olsen O, Gowing F, Kilbride C, Hilton ST, Main E, Schievano S. Clinical impact of customised positive airway pressure (PAP) therapy interfaces versus usual care in the treatment of patients with sleep-disordered breathing (3DPiPPIn): a randomised controlled trial protocol. BMJ Open. 2024 Nov 14;14(11):e087234. doi: 10.1136/bmjopen-2024-087234.
- Background: PubMed 40728908Mansell SK, Olsen O, Gowing F, Muwaffak Z, Kilbride C, Hilton S, Main E, Schievano S, Mandal S. 3DPiPPIN: 3D printing of positive airway pressure (PAP) therapy interfaces: a single site feasibility study. J Med Eng Technol. 2025 Oct;49(7):293-303. doi: 10.1080/03091902.2025.2532648. Epub 2025 Jul 29.
- BackgroundMansell S, Olsen O, Smith L, Augustt S, Kilbride C, Ridout D, Hilton S, Main E, Schievano S, Mandal S. 3D Printing Positive Pressure Interfaces (3DPiPPIn): Results From a Two-Phase Feasibility Trial [Abstract]. Am J Respir Crit Care Med 2025;211:A6945. doi: 10.1164/ajrccm.2025.211.Abstracts.A6945
- Individual participant dataSharing planned: No. The data used in this secondary analysis include potentially re-identifiable patient information. In line with the open access approach of the study's parent trial, 3DPiPPIn, individual participant data will not be shared to protect participant confidentiality.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Izaak Neri study director
King's College London
Stephanie K Mansell study director
Royal Free London NHS Foundation Trust, University College London
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Obstructive Sleep Apnoea (OSA), run by King's College London at 2 sites in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 10 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in oxygen saturation entropy from pre to six months post CPAP therapy (time frame: From baseline to six months post-initiation of CPAP therapy). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07406620, which also lists 4 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Aug 2026.