Efficient, Physiologically Realistic Lung Airflow Simulations

Walters, D. Keith; Burgreen, Greg W.; Lavallee, David M.; Thompson, David S.; Hester, Robert L.

doi:10.1109/tbme.2011.2161868

Cited by 20 publications

(31 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, automated methods to construct the geometry are lacking (e.g., van Ertbruggen et al (2005), Gemci et al (2008), Tian et al (2011), and Walters et al (2011)). Tawhai et al (2009) proposed a centerline (CL)-based method to semi-automatically construct the three-dimensional (3-D) geometry using the skeleton and the associated branch diameters in the one-dimensional (1-D) tree.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulations of aerosol delivery to the human lung with an idealized laryngeal model, image-based airway model, and automatic meshing algorithm

2017

View full text Add to dashboard Cite

The authors proposed a new method to automatically mesh computed tomography (CT)-based three-dimensional human airway geometry for computational fluid dynamics (CFD)-based simulations of pulmonary gas-flow and aerosol delivery. Traditional methods to construct and mesh realistic geometry were time-consuming, because they were done manually using image-processing and mesh-generating programs. Furthermore, most of CT thoracic image data sets do not include the upper airway structures. To overcome these issues, the proposed method consists of CFD grid-size distribution, an automatic meshing algorithm, and the addition of a laryngeal model along with turbulent velocity inflow boundary condition attached to the proximal end of the trachea. The method is based on our previously developed geometric model with irregular centerlines and cross-sections fitted to CT segmented airway surfaces, dubbed the “fitted-surface model.” The new method utilizes anatomical information obtained from the one-dimensional tree, e.g., skeleton connectivity and branch diameters, to efficiently generate optimal CFD mesh, automatically impose boundary conditions, and systematically reduce simulation results. The aerosol deposition predicted by the proposed method agreed well with the prediction by a traditional CT-based model, and the laryngeal model generated a realistic level of turbulence in the trachea. Furthermore, the computational time was reduced by factor of two without losing accuracy by using the proposed grid-size distribution. The new method is well suited for branch-by-branch analyses of gas-flow and aerosol distribution in multiple subjects due to embedded anatomical information.

show abstract

Section: Introductionmentioning

confidence: 99%

Numerical simulations of aerosol delivery to the human lung with an idealized laryngeal model, image-based airway model, and automatic meshing algorithm

2017

View full text Add to dashboard Cite

show abstract

“…In a subsequent investigation, Walters and Luke 10 applied a similar procedure in order to investigate particle deposition by combining the CFD calculations of the airflow with particle tracking simulations. The methodology has also been applied for the case of steady inhalation in a realistic, patient-specific airway geometry, 11 and a modified version has been presented for the case of unsteady breathing. 12 The objective of this study is to develop a lung model that allows accurate and efficient simulation of airflow during the entire breathing cycle for the conducting zone (up to generation 16) of the lung.…”

Section: Methodsmentioning

confidence: 99%

Design of a numerical model of lung by means of a special boundary condition in the truncated branches

Tena

Pastor

Álvarez

et al. 2016

Numer Methods Biomed Eng

View full text Add to dashboard Cite

show abstract

“…While most previous geometric methods lack automatic procedures (e.g. van Ertbruggen et al, 2005; Gemci et al, 2008; Tian et al, 2011; Walters et al, 2011), Marchandise et al (2013) proposed a method to automatically construct models for tubular geometry. However, their method is not a CL-based method because it does not reconstruct a 3-D surface from a 1-D tree and each 3-D sub-zone (patch) is not associated with a 1-D branch along with anatomical data.…”

Section: Introductionmentioning

confidence: 99%

Automatic construction of subject-specific human airway geometry including trifurcations based on a CT-segmented airway skeleton and surface

Miyawaki

Tawhai

Hoffman

et al. 2016

Biomech Model Mechanobiol

View full text Add to dashboard Cite

We propose a method to construct three-dimensional airway geometric models based on airway skeletons, or centerlines (CLs). Given a CT-segmented airway skeleton and surface, the proposed CL-based method automatically constructs subject-specific models that contain anatomical information regarding branches, include bifurcations and trifurcations, and extend from the trachea to terminal bronchioles. The resulting model can be anatomically realistic with the assistance of an image-based surface; alternatively a model with an idealized skeleton and/or branch diameters is also possible. This method systematically identifies and classifies trifurcations to successfully construct the models, which also provides the number and type of trifurcations for the analysis of the airways from an anatomical point of view. We applied this method to 16 normal and 16 severe asthmatic subjects using their computed tomography images. The average distance between the surface of the model and the image-based surface was 11% of the average voxel size of the image. The four most frequent locations of trifurcations were the left upper division bronchus, left lower lobar bronchus, right upper lobar bronchus, and right intermediate bronchus. The proposed method automatically constructed accurate subject-specific three-dimensional airway geometric models that contain anatomical information regarding branches using airway skeleton, diameters, and image-based surface geometry. The proposed method can construct (i) geometry automatically for population-based studies, (ii) trifurcations to retain the original airway topology, (iii) geometry that can be used for automatic generation of computational fluid dynamics meshes, and (iv) geometry based only on a skeleton and diameters for idealized branches.

show abstract

Efficient, Physiologically Realistic Lung Airflow Simulations

Cited by 20 publications

References 21 publications

Numerical simulations of aerosol delivery to the human lung with an idealized laryngeal model, image-based airway model, and automatic meshing algorithm

Numerical simulations of aerosol delivery to the human lung with an idealized laryngeal model, image-based airway model, and automatic meshing algorithm

Design of a numerical model of lung by means of a special boundary condition in the truncated branches

Automatic construction of subject-specific human airway geometry including trifurcations based on a CT-segmented airway skeleton and surface

Contact Info

Product

Resources

About