ApneaNCT05302219

Plethysmography Curve Variability Depending on the Breath Cycle

A study testing Respiratory rate, Tidal volume and Apnea in people with Apnea and Circulatory; Change, run by Czech Technical University in Prague at 1 site in Czechia.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

The aim of the study is to analyze the variability of plethysmography curve depending on the breath cycle (respiratory rate and tidal volume). Read more about this study

Who is it for?: Ages 18 to 30 yearsHealthy volunteers can take part
Conditions the study is for: Apnea, Circulatory; Change, Respiration
What is being tested?: Respiratory rate, Tidal volume and Apnea
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 10 participants
Where: 1 siteCzechia
Study dates: 10 Mar 2022to 30 Jun 2022
Phase: Interventional
Are there results?: None posted in the registry

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 to 30 years
All sexes
Healthy volunteers accepted
Adult

Who may be able to join

healthy volunteers/students from the Czech Technical University in Prague

Who cannot join

any acute illness
pregnancy
severe cardiovascular conditions
severe asthma or other severe respiratory conditions
diabetes
hypotension or hypertension

Trial locations and contacts

1 site in 1 country.

Czechia1 site

Faculty of Biomedical Engineering, Czech Technical University in Prague
Kladno, 27201

Other trials in Czechia

About this study

The aim of the study is to analyze the variability of plethysmography curve depending on the breath cycle (respiratory rate and tidal volume).

Read the detailed description

The plethysmography curve measured by finger sensors using pulse oximetry shows the changes in blood volume at the measured site. The presence of respiratory information within the pulse oximeter signal is a well-documented phenomenon. However, previous studies have mainly focused on extracting the respiratory rate from the plethysmography curve. The aim of this study is to analyze the variability of plethysmography curve as a function of both respiratory rate and tidal volume. Furthermore, the aim is to analyze the possibilities of apneic pause detection from the plethysmography curve.

Conditions: Apnea, Circulatory; Change, Respiration
Being tested: Respiratory rate, Tidal volume, Apnea
Keywords: pulse oximetry, photoplethysmography curve, breath cycle, apnea
Medical subject headings: Apnea, Respiratory Aspiration

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Respiratory rateOther
The participant alternates respiratory rates of 30, 15 and 7.5 breaths/min. Breathe each frequency for 2 minutes with a one-minute break.
Tidal volumeOther
The participant alternates tidal volumes of approx. 2, 1 and 0.5 litres. Breathe each tidal volume for 2 minutes with a one-minute break.
ApneaOther
The participant simulates three apneic pauses lasting 1 minute with a two-minute break.

Study groups in NCT05302219
Study group	Role	What they receive
Measurement of plethysmography curve	Experimental	Calm measurement of plethysmography curve using pulse oximetry with simultaneous monitoring of the breath cycle. In this experimental arm, participants will vary their breath cycle (different respiratory rates and different tidal volumes). Receives: Other: Respiratory rate; Other: Tidal volume; Other: Apnea

What is being measured

The primary outcome is the main question the study is designed to answer.

Variability of plethysmography curve depending on the respiratory rate
The effect of different respiratory rates (including apnea-zero respiratory rate) on the shape of the plethysmography curve will be evaluated.
Measured: 1 hour
Variability of plethysmography curve depending on the tidal volume
The effect of different tidal volumes (including apnea-zero tidal volume) on the shape of the plethysmography curve will be evaluated.
Measured: 1 hour

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

10 Mar 202230 Jun 2022

First posted31 Mar 2022
Study start10 Mar 2022
Primary completion30 Jun 2022
Study completion30 Jun 2022

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Publications (1)Papers the sponsor has linked to this study.
Other trials for ApneaStudies 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: All participants go through all assigned interventions in one study arm.
Masking: None (open label)
Enrolment: 10 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05302219
Sponsor's protocol ID: Plethysmography2022
Status last verified: Mar 2025
First submitted: 16 Mar 2022
Last updated: 25 Mar 2025
Results posted: No
Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No
Individual data sharing: No

Publications

Nilsson LM. Respiration signals from photoplethysmography. Anesth Analg. 2013 Oct;117(4):859-865. doi: 10.1213/ANE.0b013e31828098b2. Epub 2013 Feb 28.
PubMed 23449854

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Apnea trials

Study at a glance

From the registry record, last updated by the sponsor on 25 Mar 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Plethysmography Curve Variability Depending on the Breath Cycle
ClinicalTrials.gov ID: NCT05302219
Acronym / sponsor ID: Plethysmography2022
Conditions: Apnea, Circulatory; Change, Respiration
Keywords: pulse oximetry, photoplethysmography curve, breath cycle, apnea
Study type: Interventional
Recruitment status: Completed
Enrolment: 10 participants (actual)
Lead sponsor: Czech Technical University in PragueUniversity, hospital or other
Study start: 10 Mar 2022 (actual)
Primary completion: 30 Jun 2022 (actual)
Study completion: 30 Jun 2022 (actual)
First posted: 31 Mar 2022 (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.

The aim of the study is to analyze the variability of plethysmography curve depending on the breath cycle (respiratory rate and tidal volume).

Detailed description

Study design

Primary purpose: Other
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Number of arms: 1
Model description: All participants go through all assigned interventions in one study arm.

Arm	Type	Receives
Measurement of plethysmography curve	Experimental	Other: Respiratory rate, Other: Tidal volume, Other: ApneaCalm measurement of plethysmography curve using pulse oximetry with simultaneous monitoring of the breath cycle. In this experimental arm, participants will vary their breath cycle (different respiratory rates and different tidal volumes).

Who may qualify

Ages: 18 to 30 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult

Key inclusion criteria (1 listed)

healthy volunteers/students from the Czech Technical University in Prague

Key exclusion criteria (6 listed)

any acute illness
pregnancy
severe cardiovascular conditions
severe asthma or other severe respiratory conditions
diabetes

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
Respiratory rateThe participant alternates respiratory rates of 30, 15 and 7.5 breaths/min. Breathe each frequency for 2 minutes with a one-minute break.	Other	Measurement of plethysmography curve
Tidal volumeThe participant alternates tidal volumes of approx. 2, 1 and 0.5 litres. Breathe each tidal volume for 2 minutes with a one-minute break.	Other	Measurement of plethysmography curve
ApneaThe participant simulates three apneic pauses lasting 1 minute with a two-minute break.	Other	Measurement of plethysmography curve

Primary outcome

Variability of plethysmography curve depending on the respiratory rate
Time frame: 1 hour
The effect of different respiratory rates (including apnea-zero respiratory rate) on the shape of the plethysmography curve will be evaluated.
Variability of plethysmography curve depending on the tidal volume
Time frame: 1 hour
The effect of different tidal volumes (including apnea-zero tidal volume) on the shape of the plethysmography curve will be evaluated.

Results and safety

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 25 Mar 2025.
Background: PubMed 23449854Nilsson LM. Respiration signals from photoplethysmography. Anesth Analg. 2013 Oct;117(4):859-865. doi: 10.1213/ANE.0b013e31828098b2. Epub 2013 Feb 28.
Individual participant dataSharing planned: No

Related trials for Apnea

Not yet recruitingObservational study
Registry of Central Sleep Apnea Patients Undergoing remedē System Implant
Central Sleep Apnea (Diagnosis), Central Sleep Apnea Syndrome
RecruitingObservational study
Development and Clinical Validation of Artificial Intelligence Algorithms for Sleep Staging and Obstructive Sleep Apnea Screening Based on a Large-Scale Model Trained on Multimodal Physiological Signals From Diverse Populations
Sleep Apnea, Obstructive, Sleep Staging
RecruitingObservational study
Development of a Wearable Point of Care Monitoring Device for Pediatric Obstructive Sleep Apnea
Pediatric Obstructive Sleep Apnea
Not yet recruiting
Effect of High-flow Nasal Cannula Oxygenation on the Incidence of Hypoxemia During Painless Gastrointestinal Endoscopy in Patients at High Risk for Obstructive Sleep Apnea Syndrome in High-altitude Regions
Hypoxemia, Gastric Cancer (Diagnosis)
Not yet recruitingPhase 2
Oxytocin for Respiratory Compromise and Hypoventilation Induced by Drugs
Obesity & Overweight, Respiratory Depression

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.

Veronika Rafl Huttova, MSc principal investigator

Czech Technical University in Prague

Jakub Rafl, PhD principal investigator

Czech Technical University in Prague

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A study testing Respiratory rate, Tidal volume and Apnea in people with Apnea and Circulatory; Change, run by Czech Technical University in Prague at 1 site in Czechia.

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 1 inclusion and 6 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: finished, as of the sponsor's last update on 25 Mar 2025. 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 Czechia. 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?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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?

Variability of plethysmography curve depending on the respiratory rate (time frame: 1 hour). The study lists 2 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 NCT05302219, which also lists 1 linked publication.

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 25 Mar 2025.