Plethysmography Curve Variability Depending on the Breath Cycle

Study Overview
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Brief Summary
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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
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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.

Official Title
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Plethysmography Curve Variability Depending on the Breath Cycle

Conditions
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Apnea, Circulatory; Change, Respiration

Intervention / Treatment
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* Other: Respiratory rate
* Other: Tidal volume
* Other: Apnea


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy volunteers/students from the Czech Technical University in Prague Exclusion Criteria: any acute illness pregnancy severe cardiovascular conditions severe asthma or other severe respiratory conditions diabetes hypotension or hypertension

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Interventional Model Description: All participants go through all assigned interventions in one study arm.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Measurement of plethysmography curve<br>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). | Other: Respiratory rate<br>* The participant alternates respiratory rates of 30, 15 and 7.5 breaths/min. Breathe each frequency for 2 minutes with a one-minute break.<br>Other: Tidal volume<br>* 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.<br>Other: Apnea<br>* The participant simulates three apneic pauses lasting 1 minute with a two-minute break.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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. | 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. | 1 hour | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pulse oximetry, photoplethysmography curve, breath cycle, apnea