Related Experiment Video
Updated: Oct 6, 2025

Combining Volumetric Capnography And Barometric Plethysmography To Measure The Lung Structure-function Relationship
Published on: January 8, 2019
Comparison of Respiratory Calibration Methods for the Estimation of Lung Volume in Children With and Without
1Department of Speech, Language, and Hearing Sciences, University of Arizona, Tucson.
Insights
The least squares method with both rib cage and abdomen corrections (LsqRC/AB) is the most accurate method for estimating lung volumes in children. This method is effective for children with and without neuromotor disorders.
Area of Science:
- Pediatric respiratory physiology
- Biomedical engineering
- Pulmonary function testing
Background:
- Accurate lung volume estimation is crucial for assessing respiratory health in children.
- Existing respiratory calibration methods require validation for pediatric populations.
- Inductive plethysmography is a non-invasive technique for measuring respiratory kinematics.
Purpose of the Study:
- To validate common respiratory calibration methods for estimating lung volume in children.
- To compare the accuracy of different correction factor calculation methods.
- To assess the impact of calibration tasks on lung volume estimation.
Main Methods:
- Respiratory kinematic data collected using inductive plethysmography from 81 typically developing children and 9 with neuromotor disorders.
- Three calibration methods evaluated: LsqRC/AB, LsqRC, and Banzett.
- Lung volume estimation errors calculated by comparing spirometry data with estimated volumes.
Main Results:
- The LsqRC/AB method showed significantly smaller lung volume estimation errors in typically developing children.
- Lung volume estimation errors decreased with increasing age across all methods.
- For children with neuromotor disorders, LsqRC/AB and LsqRC were more accurate than Banzett.
Conclusions:
- The LsqRC/AB method, using rest breathing calibration, is the most accurate and efficient for children.
- This validated method is suitable for both typically developing children and those with neuromotor disorders.
- No significant difference in accuracy for LsqRC/AB and LsqRC when using speech-like breathing calibration.
Purpose:
The primary purpose of this study was to validate common respiratory calibration methods for estimating lung volume in children.
Method:
Respiratory kinematic data were collected via inductive plethysmography from 81 typically developing children and nine children with neuromotor disorders. Correction factors for the rib cage and abdomen were calculated using three different methods: (a) least squares method with both rib cage and abdomen corrections (LsqRC/AB), (b) least squares method with rib cage correction only (LsqRC), and (c) a standard 2:1 rib-cage-to-abdomen ratio (Banzett). Correction factors for the LsqRC/AB and LsqRC methods were calculated with and without the use of the speech-like breathing calibration task. Lung volume estimation errors were calculated by comparing the estimated lung volumes based on the correction factors and the actual lung volumes acquired from a spirometer, normalized to each participant's vital capacity.
Results:
For typically developing children, the LsqRC/AB method resulted in significantly smaller lung volume estimation errors compared with other methods. Lung volume estimation errors decreased as age increased for each method. For the children with neuromotor disorders, the LsqRC/AB and LsqRC methods resulted in significantly smaller lung volume estimation errors than the Banzett method but were not significantly different from one another. There were no significant differences in lung volume estimation errors for the LsqRC/AB and LsqRC methods when the correction factors were calculated with and without the speech-like breathing calibration task.
Conclusion:
The LsqRC/AB method exclusively utilizing the rest breathing calibration task is the most accurate and efficient respiratory calibration method for use with children with and without neuromotor disorders at this time.
Related Concept Videos
Respiratory Volumes
Tidal Volume (TV) Tidal volume (TV) is the air inhaled or exhaled in a...
Respiratory Volumes and Capacities I
Respiratory Volumes and Capacities
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:
Assessment of Respiration
Subjective Assessment: Nurses interview the patient to gather information directly during the subjective assessment. It includes questions about the individual's medical history, medications, and symptoms, focusing on past respiratory conditions like...

