Related Experiment Video
Updated: Jun 7, 2026
Conducting Respiratory Oscillometry in an Outpatient Setting
Published on: April 8, 2022
In vitro performance comparison of the Sensormedics 3100A and B high-frequency oscillatory ventilators
Jason W Custer1, Andaleeb Ahmed, David W Kaczka
1Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institute, Baltimore, MD, USA.
Objective:
The Sensormedics 3100A and 3100B are widely used to provide high-frequency oscillatory ventilation in clinical practice. Infants and children <35 kg are typically oscillated with the 3100A and >35 kg with the 3100B. This study compares the effect of ventilator and patient parameters on delivered tidal volume during high-frequency oscillatory ventilation of a test lung with these devices.
Design:
Laboratory-based study.
Subjects:
Test lung and Sensormedics 3100A and 3100B high-frequency oscillators.
Interventions:
A previously validated hot-wire flowmeter (Florian) was placed in series with either a 3100A (n = 3) or 3100B (n = 3) ventilator and a Michigan test lung. Tidal volumes were measured over a range of mean airway pressure, inspiratory:expiratory ratio, frequency, pressure amplitude, and endotracheal tube internal diameter.
Measurements And Main Results:
The 3100A and 3100B delivered similar tidal volumes across a range of ventilator parameters for an inspiratory:expiratory ratio of 1:1, differing by <10%. However, at an inspiratory:expiratory ratio of 1:2, there was a statistically significant decrease in tidal volume for the 3100B compared with the 3100A at lower frequencies, which was partially mitigated by increasing pressure amplitude. The difference in the generated pressure and flow waveforms may account for the observed tidal volume differences between the high-frequency oscillatory ventilation models. Delivered tidal volume was highly dependent on endotracheal tube size.
Conclusions:
Multiple variables contribute to the delivered tidal volume during high-frequency oscillatory ventilation, including ventilator model selection and endotracheal tube size. It is possible that real-time, clinical monitoring of delivered tidal volume during high-frequency oscillatory ventilation would allow better titration and maximize performance of these ventilators in caring for critically ill patients.
Related Concept Videos
01:23Mechanical Ventilation II: Invasive Ventilation
Negative-Pressure Ventilators
Negative-pressure ventilators create a vacuum around the chest or body to draw air into the lungs, simulating breathing. This method does not require an...
01:23Mechanical Ventilation III: Noninvasive Ventilation
Noninvasive Positive-Pressure Ventilation (NIPPV)
01:29Mechanical Ventilation I: Indication and Settings
01:14Ventilatory Modes
There are three ventilatory modes: full support, partial support, and spontaneous. These are described below.
Full Support Modes
Full support modes include controlled mechanical ventilation, continuous mandatory...
01:20Assessment 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:
01:29Assessment 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: