Short answer

Incorporate dynamic physiological variations, such as glottal aperture changes, into the design and simulation of respiratory devices and therapies to improve efficacy.

Field: Human Factors
Source: HAL (Le Centre pour la Communication Scientifique Directe) (2015)
Method: Experimental and Computational Fluid Dynamics (CFD) simulation
Sample: 20 participants
Evidence: Strong effect

The opening and closing of the glottis during breathing, a dynamic human physiological factor, directly influences the narrowing of the upper airways and consequently impacts where inhaled aerosols deposit. This human factors research insight is drawn from a 2015 study published in HAL (Le Centre pour la Communication Scientifique Directe). Using Experimental and computational fluid dynamics (cfd) simulation with 20 participants, researchers explored how this design variable affects real-world outcomes. The key design takeaway: Incorporate dynamic physiological variations, such as glottal aperture changes, into the design and simulation of respiratory devices and therapies to improve efficacy.

Study

Human FactorsHigh ImpactStrong effect

Dynamic Glottis Aperture Significantly Alters Aerosol Deposition in Airways

HAL (Le Centre pour la Communication Scientifique Directe) · 2015

Key Findings

01Glottal geometry during breathing is highly variable, depending on respiratory phase, tidal volume, and breathing frequency.
02Two distinct groups of subjects were identified based on glottal area variation: some with relatively constant areas and others with significant dynamic changes (average 26% variation in males).
03The dynamic behavior of the glottis significantly affects aerosol deposition in the upper airways.

Application

Design takeaway

Incorporate dynamic physiological variations, such as glottal aperture changes, into the design and simulation of respiratory devices and therapies to improve efficacy.

How to apply

When designing or evaluating inhaled drug delivery systems, use computational models that simulate dynamic glottal changes and airflow patterns to predict deposition more accurately.

Project actions

01Consider how human body movements and internal changes affect product performance.
02When simulating airflow or fluid dynamics, think about whether static or dynamic models are more appropriate for your design context.

Method & Evidence

AimTo investigate the evolution of glottal area during human breathing and predict the effects of a dynamic glottis and realistic airflow conditions on aerosol deposition in the upper airways.

MethodExperimental and Computational Fluid Dynamics (CFD) simulation

ProcedureA clinical study recorded glottal area variations via laryngoscopic video and airflow rate using an oral flowmeter in 20 healthy volunteers during various breathing tasks. These experimental measurements, along with anatomical data, were used to create a 3D model of the upper airways. Cyclic simulations were then performed to study aerosol transport and deposition, evaluating the influence of cyclic flow and glottal dynamics.

Sample20 participants

ContextInhaled therapy and respiratory system design

Variables

IVGlottal area variation (dynamic vs. static), breathing frequency, tidal volume

DVAerosol deposition location and quantity in upper airways

CVParticipant sex, age (implicitly), breathing tasks, carrier gas type (in simulations)

Strengths & Limitations

Strengths

+Combines experimental human data with advanced computational modeling.
+Investigates a critical, often overlooked, dynamic physiological factor in airway function.

Limitations

The complexity of simulating dynamic glottal movement and its precise interaction with airflow can be challenging. Obtaining accurate individual glottal data for personalized simulations might be difficult.

Reliability & validity

Reliability could be enhanced by repeating measurements and using standardized breathing protocols. Validity is supported by the combination of experimental data and simulation, but the idealised model introduces a potential limitation.

Think critically

How might the variability in glottal motion observed in this study influence the design of a 'one-size-fits-all' inhaler device versus a personalized therapeutic approach?

Design Principles

"Design for physiological variability: Acknowledge and integrate the dynamic and variable nature of human physiology into design solutions."

Understanding the dynamic nature of the glottis is crucial for designing more effective inhaled drug delivery systems. This research highlights that a static model of the airways may not accurately predict aerosol deposition, leading to suboptimal therapeutic outcomes.

What This Means for Your Design

How much your throat opens and closes when you breathe affects where medicine from an inhaler lands in your body.

How to use in your project

1.Use this research to justify the need for dynamic simulations in your design project, especially if it involves airflow or delivery systems.
2.Cite this study when discussing the limitations of static models or the importance of physiological factors in your design process.

Add to My Project

Quick Cite

Paragraph starter

Research by Scheinherr (2015) highlights the significant impact of dynamic glottal aperture variations on aerosol deposition within the upper airways during breathing. This underscores the importance of incorporating such physiological dynamics into design simulations for inhaled therapies, as static airway models may not accurately predict drug delivery efficacy.

Source

HAL (Le Centre pour la Communication Scientifique Directe)

Impact du mouvement glottique sur l'écoulement et le dépôt d'aérosols dans les voies aériennes supérieures lors de la respiration humaine

journal · 2015

View source

Questions About This Research

What does the research say about dynamic glottis aperture significantly alters aerosol deposition in airways?: Incorporate dynamic physiological variations, such as glottal aperture changes, into the design and simulation of respiratory devices and therapies to improve efficacy. Evidence: HAL (Le Centre pour la Communication Scientifique Directe) (2015).
Why does "Dynamic Glottis Aperture Significantly Alters Aerosol Deposition in Airways" matter for design?: Understanding the dynamic nature of the glottis is crucial for designing more effective inhaled drug delivery systems. This research highlights that a static model of the airways may not accurately predict aerosol deposition, leading to suboptimal therapeutic outcomes.
How can designers apply this research?: Incorporate dynamic physiological variations, such as glottal aperture changes, into the design and simulation of respiratory devices and therapies to improve efficacy.
What were the main findings?: Glottal geometry during breathing is highly variable, depending on respiratory phase, tidal volume, and breathing frequency.. Two distinct groups of subjects were identified based on glottal area variation: some with relatively constant areas and others with significant dynamic changes (average 26% variation in males).. The dynamic behavior of the glottis significantly affects aerosol deposition in the upper airways.
What research method was used?: Experimental and Computational Fluid Dynamics (CFD) simulation with 20 participants.
How strong is the evidence?: Evidence strength is rated Strong effect, based on a 2015 journal from HAL (Le Centre pour la Communication Scientifique Directe).
What should I do differently in my next project?: When designing or evaluating inhaled drug delivery systems, use computational models that simulate dynamic glottal changes and airflow patterns to predict deposition more accurately.
What are the limitations?: The study focused on healthy volunteers, and results may differ for individuals with respiratory conditions. The idealised airway model may not capture all individual anatomical nuances.