Plethysmography Curve Variability Depending on the Breath Cycle

Not Applicable

Completed

• Conditions: Respiration; Apnea; Circulatory; Change
• Interventions: Other: Respiratory rate; Other: Tidal volume; Other: Apnea

• Registration Number: NCT05302219
• Lead Sponsor: Czech Technical University in Prague

Brief Summary

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

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.

Study Timeline

• Study Start: 2022-03-10
• Study First Submitted: 2022-03-16
• Study First Submitted QC: 2022-03-29
• Study First Posted: 2022-03-31
• Primary Completion: 2022-06-30
• Study Completion: 2022-06-30
• Status Verified: 2025-03
• Last Update Submitted: 2025-03-24
• Last Update Posted: 2025-03-25

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 10

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Measurement of plethysmography curve	Respiratory rate	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).
Measurement of plethysmography curve	Tidal volume	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).
Measurement of plethysmography curve	Apnea	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).

Primary Outcome Measures

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

Trial Locations

Locations (1)

Faculty of Biomedical Engineering, Czech Technical University in Prague; 🇨🇿 Kladno, Czechia