Related Experiment Video
Updated: Mar 12, 2026

Conducting Respiratory Oscillometry in an Outpatient Setting
Published on: April 8, 2022
Validation of Polyvinylidene Fluoride Impedance Sensor for Respiratory Event Classification during Polysomnography in
Anne G Griffiths1, Pallavi P Patwari2, Darius A Loghmanee3,4
1Children's Respiratory and Critical Care Specialists, Minneapolis, MN.
Study Objectives:
Polysomnography is the gold standard for diagnosis and characterization of severity of sleep-disordered breathing. Accuracy and reliability of the technology used are critical to the integrity of the study's interpretation. Strict criteria for obstructive sleep apnea in children are lacking and diagnosis often requires consideration of frequency of respiratory events in addition to other measures. Current American Academy of Sleep Medicine recommendations for pediatric patients includes use of respiratory inductance plethysmography (RIP) belts, whereas polyvinylidene fluoride (PVDF) belts are currently only acceptable for use in adults. We hypothesized that PVDF belts would be equally effective as RIP belts for detection of respiratory effort and events in children.
Methods:
Children ages 2-17 y were recruited from a large pediatric tertiary referral center after obtaining consent for participation. Fifty subjects were recruited (average age, 7.8 y). Clinically relevant limits of agreement were predetermined to be a difference in total count of obstructive or central apneas or hypopneas of ± 5 events.
Results:
Scoring of respiratory events was not significantly different by belt type based on Bland-Altman plots of total apnea-hypopnea index and obstructive apneas. Obstructive hypopneas scoring ranged beyond our clinical limit of agreement. Findings in obese subjects were consistent with the larger sample with the exception of an increase in outliers. Artifact amount was comparable (RIP 10.9% ± 22.5% and PVDF 10.5% ± 19.5%).
Conclusions:
Based on these findings, PVDF belts appear to be as effective as RIP belts in detection of respiratory effort and events in children.
Commentary:
A commentary on this article appears in this issue on page 159.
Related Concept Videos
Assessment of Ventilation I: Respiratory Rate
A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma.
Critical Guidelines for Assessing Ventilation:
Assessment of Ventilation II: Respiratory Depth and Rhythm
Respiratory depth measures the volume of air inhaled or exhaled during a breath. It can vary from shallow to deep and typically remains consistent when a person is at rest or asleep. Occasionally, individuals will automatically inhale deeply, known as sighing, which inflates the lungs with more air than normal breathing.
To assess respiratory depth, observe the degree of chest excursion or movement:

