Circadian RhythmsNCT07744711
Real-World Use of an iPad-Based Light Therapy App, With Optional Biomarker Collection
A study testing Circadian OS iPad-based light app in people with Circadian Rhythms, run by Circadian OS, Inc at 1 site in United States.
Trial summary
This study looks at how adults use an iPad-based light app in everyday life. Light is the main signal that sets the body's internal clock, which controls daily rhythms in sleep, alertness, and many other body systems. Indoor living means many people do not get bright light at a consistent time each day. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Circadian Rhythms
- What is being tested?
- Circadian OS iPad-based light app
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 50 participants
- Where
- 1 siteUnited States
- Study dates
- 17 Jul 2026to 30 Jun 2028
- Phase
- Interventional
- 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
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Adult 18 years of age or older
- Able to read, understand, and provide written informed consent in English
- Has access to a compatible iPad capable of running the study app for the duration of the exposure period, or is willing to use a Sponsor-supplied iPad
- U.S. resident, able to be in the NYC metropolitan area for the study
- Member of the Sponsor's network (friends, family, advisors, investors, employees, or contractors)
- If opting in to the biomarker sub-study: weighs at least 110 lb (50 kg), and meets standard venipuncture eligibility on the day of collection
Who cannot join
- Diagnosed bipolar disorder, or history of light-induced manic or hypomanic episodes
- Pregnant, attempting to become pregnant, or breastfeeding
- Diagnosed photosensitivity disorder, retinal disease, or use of medications known to cause significant photosensitivity, at investigator discretion based on disclosed medications
- Currently using prescription light therapy, or actively enrolled in another light-related research study
- Unable to consent for themselves (participants requiring enrollment by a legally authorized representative are not eligible)
- Biomarker sub-study only: acutely unwell, febrile, or reporting acute infectious symptoms on the study day
Show all 9Show fewer
- Biomarker sub-study only: known bleeding diathesis, anticoagulant use other than low-dose aspirin, severe needle phobia, or whole-blood or plasma donation within the prior two weeks
- Biomarker sub-study only: member of the study or laboratory team who would otherwise process their own sample
- Any condition that, in the judgment of the investigator or attending phlebotomist or nurse, would make participation unsafe
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Longitudinal Patterns of Use of the Circadian OS iPad-Based Light App, With Optional Biomarker Collection
This study looks at how adults use an iPad-based light app in everyday life.
Light is the main signal that sets the body's internal clock, which controls daily rhythms in sleep, alertness, and many other body systems. Indoor living means many people do not get bright light at a consistent time each day.
Read more
The app uses the iPad screen to deliver light while people watch videos, read, or browse. It suggests about one hour of use per day, started within about two hours of waking. It does not require anyone to follow that schedule, and no one is locked out for using it more, less, or at other times. The app shows people when they are positioned to receive the intended light, records how the app is used, and asks short questions about sleep.
The main questions this study aims to answer are:
- How often, how long, and at what time of day do people use the app?
- What do people mostly do during light-delivery sessions?
- What do people think of the app, and how easy is it to use?
Participants will use the app on an iPad for up to eight weeks, answer short questions about their sleep and how they feel, and share feedback about their experience.
Participants may also choose to take part in optional sub-studies. They can wear a device the sponsor provides to record movement, light exposure, and skin temperature, or share data from a wearable device they already use. They can also give blood, saliva, or urine samples, which researchers will use to describe daily patterns in clock-related genes and other markers. These sub-studies are entirely exploratory and voluntary, and participants can take part in the main study without them.
Participants will not receive results from any samples they give. This study does not provide medical treatment, and it is not designed to determine whether the app treats or improves any medical condition.
Read the detailed description
This is a single-site, longitudinal study evaluating how adults use KairOS, an iPad-based light application developed by Circadian OS, Inc., in everyday life for up to eight weeks. Participants are encouraged to use the app for approximately 60 minutes daily within two hours of waking, but use is not enforced. Zero-use stretches, partial weeks, and re-engagement after a gap are recorded as participation data rather than protocol deviations. App telemetry, sleep logs, and participant feedback are used to characterize patterns of use and overall usability. Participants may also opt into an exploratory biomarker sub-study involving collection of blood, saliva, or urine samples; no laboratory results are returned to participants. Other optional activities include actigraphy, light-exposure monitoring, and moderated task-observation sessions.
- Conditions
- Circadian Rhythms
- Being tested
- Circadian OS iPad-based light app
- Keywords
- chronotype, phototherapy, chronotherapy, photoentrainment, light therapy, real-world evidence, patterns of use, circadian medicine
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Circadian OS iPad-based light appDevice
Also called KairOS, Circadian OS app
Software-based light-delivery platform running on an off-the-shelf iPad. The app uses the display to deliver light targeting a specified circadian stimulus (CS ≥ 0.3), integrating spectrum and intensity at the eye. It runs closed-loop: screen luminance is calibrated in advance, the iPad camera tracks viewing distance and gaze direction, and the app computes the dose reaching the eye in real time, signaling whether the user is positioned to receive it. Session start-time recommendations are anchored to each participant's habitual wake time, derived from the Munich ChronoType Questionnaire. Onboarding presents a recommended envelope of approximately 60 minutes per day within approximately 2 hours of habitual wake. Use is not enforced and the app does not lock out off-envelope use. Participants use the app while streaming, reading, or browsing as they normally would.
| Study group | Role | What they receive |
|---|---|---|
| Circadian OS Light App (KairOS) | Experimental | Participants receive the investigational Circadian OS iPad-based light app and use it in their normal environment over a defined exposure period. App onboarding presents a recommended use envelope of approximately 60 minutes per day within approximately 2 hours of habitual wake time, anchored to the participant's Munich ChronoType Questionnaire response. Use is not enforced: the app does not lock out participants who use it less, more, or outside the recommended window, and non-use is recorded as participation data. Participants complete brief in-app check-ins on sleep and experience, plus periodic usability surveys. Optional sub-studies (actigraphy, biomarker collection, moderated human-factors observation) are independently elected by participants within this single arm. Receives: Device: Circadian OS iPad-based light app |
What is being measured
The primary outcome is the main question the study is designed to answer.
Frequency of Circadian OS app (KairOS) use
Number of light-delivery sessions completed per participant per week, captured by in-app telemetry.
Measured: From initiation of app use through the end of the app-exposure period, up to eight weeks
Duration of app use: minutes of light exposure per session
Duration in minutes of each light-delivery session, captured by in-app telemetry.
Measured: From initiation of app use through the end of the app-exposure period, up to eight weeks
Timing of app use relative to habitual wake time
Start time of each light-delivery session, expressed as hours elapsed since the participant's habitual wake time, as measured by the Munich Chronotype Questionnaire completed at baseline.
Measured: From initiation of app use through the end of the app-exposure period, up to eight weeks
Context of app use
Concurrent on-screen activity during light-delivery sessions, captured by in-app telemetry.
Measured: From initiation of app use through the end of the app-exposure period, up to eight weeks
Secondary outcomes (6)
Participant-reported feedback on the app experience, usability, and perceived effects
Structured and free-text participant feedback on the app experience, usability, and perceived effects, including the Perceived Effects Scale (Compared to Before the Study), a study-specific 5-point Likert measure (range 1-5, higher scores indicate a better perceived outcome; 1 = Much worse, 2 = Somewhat worse, 3 = No change, 4 = Somewhat better, 5 = Much better).
Measured: Weekly during the app-exposure period and at the end of the app-exposure period, up to eight weeks
Self-reported sleep and circadian-rhythm parameters during the exposure period
Participant-reported sleep parameters captured through an in-app daily sleep log during the exposure period, including bedtime, wake time, nighttime awakenings, napping, and sleep quality. Weekly participant check-ins capture sleep quality and daytime alertness relative to usual.
Measured: From initiation of app use through the end of the app-exposure period, up to eight weeks
Drop-off and return-to-use patterns
Consecutive zero-use days per participant, partial weeks of use, and re-engagement events following a use gap.
Measured: From initiation of app use through the end of the app-exposure period, up to eight weeks
System Usability Scale (SUS) score
Participant-completed 10-item System Usability Scale, scored 0-100, with higher scores indicating better perceived usability.
Measured: End of Week 1 and end of the app-exposure period; a single administration is done at the end of Week 1 when the app-exposure period is one week
Number of Use Errors Identified During App Use
Use errors identified from in-app telemetry and participant-reported problems, documented with description and frequency.
Measured: From initiation of app use through the end of the app-exposure period, up to eight weeks
Root-Cause Category of Identified Use Errors
Identified use errors are categorized by root cause (perception, cognition, or action) per human-factors methodology, based on in-app telemetry and participant-reported problems.
Measured: From initiation of app use through the end of the app-exposure period, up to eight weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Aug 2026
- Study start17 Jul 2026
- Primary completion30 Jun 2027 (estimated)
- Study completion30 Jun 2028 (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 Circadian RhythmsStudies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Single-arm, open-label, naturalistic device-use study. All participants receive the investigational app and use it without enforcement or lockout. Adherence to the recommended use envelope is not required, and non-use, partial weeks, and re-engagement are recorded as participation data rather than protocol deviations. Optional sub-studies (actigraphy, biomarker collection, moderated human-factors sessions) are independently elected by participants and do not constitute separate assigned arms.
- Masking
- None (open label)
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Circadian OS, Inc
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Sofia Axelrod, PhD, Principal investigator, Circadian OS, Inc
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07744711
- Sponsor's protocol ID
- COS-20262058
- Status last verified
- Aug 2026
- First submitted
- 19 Jul 2026
- Last updated
- 4 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No: Individual participant data will not be shared outside the Sponsor. Per the study protocol, no coded or identified data are shared outside the Sponsor, and no biospecimens are shipped to any external laboratory. The Sponsor will return to the IRB before any external sharing is contemplated. Participant consent does not authorize sharing of individual participant data outside the study team.
Publications
Patke A, Young MW, Axelrod S. Molecular mechanisms and physiological importance of circadian rhythms. Nat Rev Mol Cell Biol. 2020 Feb;21(2):67-84. doi: 10.1038/s41580-019-0179-2. Epub 2019 Nov 25.
PubMed 31768006Allada R, Bass J. Circadian Mechanisms in Medicine. N Engl J Med. 2021 Feb 11;384(6):550-561. doi: 10.1056/NEJMra1802337. No abstract available.
PubMed 33567194Roenneberg T, Pilz LK, Zerbini G, Winnebeck EC. Chronotype and Social Jetlag: A (Self-) Critical Review. Biology (Basel). 2019 Jul 12;8(3):54. doi: 10.3390/biology8030054.
PubMed 31336976Rea MS, Nagare R, Figueiro MG. Modeling Circadian Phototransduction: Retinal Neurophysiology and Neuroanatomy. Front Neurosci. 2021 Feb 5;14:615305. doi: 10.3389/fnins.2020.615305. eCollection 2020.
PubMed 33613175
Study at a glance
From the registry record, last updated by the sponsor on 4 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Longitudinal Patterns of Use of the Circadian OS iPad-Based Light App, With Optional Biomarker Collection
- ClinicalTrials.gov ID
- NCT07744711
- Acronym / sponsor ID
- COS-20262058
- Conditions
- Circadian Rhythms
- Keywords
- chronotype, phototherapy, chronotherapy, photoentrainment, light therapy, real-world evidence, patterns of use, circadian medicine
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Circadian OS, IncIndustry (pharma, biotech, devices)
- Study start
- 17 Jul 2026 (actual)
- Primary completion
- 30 Jun 2027 (estimated)
- Study completion
- 30 Jun 2028 (estimated)
- First posted
- 4 Aug 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 study looks at how adults use an iPad-based light app in everyday life.
Light is the main signal that sets the body's internal clock, which controls daily rhythms in sleep, alertness, and many other body systems. Indoor living means many people do not get bright light at a consistent time each day.
The app uses the iPad screen to deliver light while people watch videos, read, or browse. It suggests about one hour of use per day, started within about two hours of waking. It does not require anyone to follow that schedule, and no one is locked out for using it more, less, or at other times. The app shows people when they are positioned to receive the intended light, records how the app is used, and asks short questions about sleep.
The main questions this study aims to answer are:
- How often, how long, and at what time of day do people use the app?
- What do people mostly do during light-delivery sessions?
- What do people think of the app, and how easy is it to use?
Participants will use the app on an iPad for up to eight weeks, answer short questions about their sleep and how they feel, and share feedback about their experience.
Participants may also choose to take part in optional sub-studies. They can wear a device the sponsor provides to record movement, light exposure, and skin temperature, or share data from a wearable device they already use. They can also give blood, saliva, or urine samples, which researchers will use to describe daily patterns in clock-related genes and other markers. These sub-studies are entirely exploratory and voluntary, and participants can take part in the main study without them.
Participants will not receive results from any samples they give. This study does not provide medical treatment, and it is not designed to determine whether the app treats or improves any medical condition.
Detailed description
This is a single-site, longitudinal study evaluating how adults use KairOS, an iPad-based light application developed by Circadian OS, Inc., in everyday life for up to eight weeks. Participants are encouraged to use the app for approximately 60 minutes daily within two hours of waking, but use is not enforced. Zero-use stretches, partial weeks, and re-engagement after a gap are recorded as participation data rather than protocol deviations. App telemetry, sleep logs, and participant feedback are used to characterize patterns of use and overall usability. Participants may also opt into an exploratory biomarker sub-study involving collection of blood, saliva, or urine samples; no laboratory results are returned to participants. Other optional activities include actigraphy, light-exposure monitoring, and moderated task-observation sessions.
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Single-arm, open-label, naturalistic device-use study. All participants receive the investigational app and use it without enforcement or lockout. Adherence to the recommended use envelope is not required, and non-use, partial weeks, and re-engagement are recorded as participation data rather than protocol deviations. Optional sub-studies (actigraphy, biomarker collection, moderated human-factors sessions) are independently elected by participants and do not constitute separate assigned arms.
| Arm | Type | Receives |
|---|---|---|
| Circadian OS Light App (KairOS) | Experimental | Device: Circadian OS iPad-based light appParticipants receive the investigational Circadian OS iPad-based light app and use it in their normal environment over a defined exposure period. App onboarding presents a recommended use envelope of approximately 60 minutes per day within approximately 2 hours of habitual wake time, anchored to the participant's Munich ChronoType Questionnaire response. Use is not enforced: the app does not lock out participants who use it less, more, or outside the recommended window, and non-use is recorded as participation data. Participants complete brief in-app check-ins on sleep and experience, plus periodic usability surveys. Optional sub-studies (actigraphy, biomarker collection, moderated human-factors observation) are independently elected by participants within this single arm. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Adult 18 years of age or older
- Able to read, understand, and provide written informed consent in English
- Has access to a compatible iPad capable of running the study app for the duration of the exposure period, or is willing to use a Sponsor-supplied iPad
- U.S. resident, able to be in the NYC metropolitan area for the study
- Member of the Sponsor's network (friends, family, advisors, investors, employees, or contractors)
Key exclusion criteria (9 listed)
- Diagnosed bipolar disorder, or history of light-induced manic or hypomanic episodes
- Pregnant, attempting to become pregnant, or breastfeeding
- Diagnosed photosensitivity disorder, retinal disease, or use of medications known to cause significant photosensitivity, at investigator discretion based on disclosed medications
- Currently using prescription light therapy, or actively enrolled in another light-related research study
- Unable to consent for themselves (participants requiring enrollment by a legally authorized representative are not eligible)
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 |
|---|---|---|
| Circadian OS iPad-based light appAlso: KairOS, Circadian OS appSoftware-based light-delivery platform running on an off-the-shelf iPad. The app uses the display to deliver light targeting a specified circadian stimulus (CS ≥ 0.3), integrating spectrum and intensity at the eye. It runs closed-loop: screen luminance is calibrated in advance, the iPad camera tracks viewing distance and gaze direction, and the app computes the dose reaching the eye in real time, signaling whether the user is positioned to receive it. Session start-time recommendations are anchored to each participant's habitual wake time, derived from the Munich ChronoType Questionnaire. Onboarding presents a recommended envelope of approximately 60 minutes per day within approximately 2 hours of habitual wake. Use is not enforced and the app does not lock out off-envelope use. Participants use the app while streaming, reading, or browsing as they normally would. | Device | Circadian OS Light App (KairOS) |
Primary outcome
Frequency of Circadian OS app (KairOS) use
Time frame: From initiation of app use through the end of the app-exposure period, up to eight weeks
Number of light-delivery sessions completed per participant per week, captured by in-app telemetry.
Duration of app use: minutes of light exposure per session
Time frame: From initiation of app use through the end of the app-exposure period, up to eight weeks
Duration in minutes of each light-delivery session, captured by in-app telemetry.
Timing of app use relative to habitual wake time
Time frame: From initiation of app use through the end of the app-exposure period, up to eight weeks
Start time of each light-delivery session, expressed as hours elapsed since the participant's habitual wake time, as measured by the Munich Chronotype Questionnaire completed at baseline.
Context of app use
Time frame: From initiation of app use through the end of the app-exposure period, up to eight weeks
Concurrent on-screen activity during light-delivery sessions, captured by in-app telemetry.
6 secondary outcomes
Participant-reported feedback on the app experience, usability, and perceived effects
Time frame: Weekly during the app-exposure period and at the end of the app-exposure period, up to eight weeks
Self-reported sleep and circadian-rhythm parameters during the exposure period
Time frame: From initiation of app use through the end of the app-exposure period, up to eight weeks
Drop-off and return-to-use patterns
Time frame: From initiation of app use through the end of the app-exposure period, up to eight weeks
System Usability Scale (SUS) score
Time frame: End of Week 1 and end of the app-exposure period; a single administration is done at the end of Week 1 when the app-exposure period is one week
Number of Use Errors Identified During App Use
Time frame: From initiation of app use through the end of the app-exposure period, up to eight weeks
Root-Cause Category of Identified Use Errors
Time frame: From initiation of app use through the end of the app-exposure period, up to eight weeks
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 4 Aug 2026.
- Background: PubMed 31768006Patke A, Young MW, Axelrod S. Molecular mechanisms and physiological importance of circadian rhythms. Nat Rev Mol Cell Biol. 2020 Feb;21(2):67-84. doi: 10.1038/s41580-019-0179-2. Epub 2019 Nov 25.
- Background: PubMed 33567194Allada R, Bass J. Circadian Mechanisms in Medicine. N Engl J Med. 2021 Feb 11;384(6):550-561. doi: 10.1056/NEJMra1802337. No abstract available.
- Background: PubMed 31336976Roenneberg T, Pilz LK, Zerbini G, Winnebeck EC. Chronotype and Social Jetlag: A (Self-) Critical Review. Biology (Basel). 2019 Jul 12;8(3):54. doi: 10.3390/biology8030054.
- Background: PubMed 33613175Rea MS, Nagare R, Figueiro MG. Modeling Circadian Phototransduction: Retinal Neurophysiology and Neuroanatomy. Front Neurosci. 2021 Feb 5;14:615305. doi: 10.3389/fnins.2020.615305. eCollection 2020.
- Individual participant dataSharing planned: No. Individual participant data will not be shared outside the Sponsor. Per the study protocol, no coded or identified data are shared outside the Sponsor, and no biospecimens are shipped to any external laboratory. The Sponsor will return to the IRB before any external sharing is contemplated. Participant consent does not authorize sharing of individual participant data outside the study team.
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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.
Sofia Axelrod, PhD principal investigator
Circadian OS, Inc
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Circadian OS iPad-based light app in people with Circadian Rhythms, run by Circadian OS, Inc at 1 site in United States.
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 6 inclusion and 9 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: enrolling by invitation, as of the sponsor's last update on 4 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 1 site in United States. 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?
Frequency of Circadian OS app (KairOS) use (time frame: From initiation of app use through the end of the app-exposure period, up to eight weeks). The study lists 4 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 NCT07744711, 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 4 Aug 2026.