Air Flow in Patient with Tracheotomy

What is a Tracheotomy?

Patient with Hood™ stoma stent

A tracheotomy operation is a procedure whereby a hole is cut in the patient's trachea to provide an alternative route for air to enter and leave the lungs. After the patient's trachea has been opened a plastic or metal tube called a tracheotomy tube is inserted and held in place. This tube acts like a windpipe and allows the patient to breathe.

Mesh Generation in ScanIP and ⁺ScanFE

Segmentation of trachea, stent, bones, tissue and lungs

FE mesh of trachea and implant

CFD of airflow in Fluent

An in vivo CT scan of a patient was imported into ScanIP and segmented into five different structures:

• Trachea & airways
• Tracheotomy tube (i.e. Hood™ stoma stent)
• Bones
• Soft tissue
• Lungs

The airways and the implant were meshed within ⁺ScanFE and exported in Fluent format. ⁺ScanFE generated a cell deformation index based on a comparison between enclosed and enclosing spheres for each cell. All cells generated by this technique are of good shape with low index values.

Fluent Simulation

Computations were performed on exhalation at a flow rate 30 cm³/s (a gentle exhalation) with the implant blocked off and with it open. Results shown on image give the velocity magnitude and total pressure on this plane for the case where the implant is blocked up.

Publication

Tabor, G., Xuan, B., Fureder, R., West, T., Young, P., 2004. On Automating the Generation of CFD Models Based on 3D Data: Industrial and Biomedical Applications. In: ECCOMAS 2004, 24-28 July 2004 Jyväskylä.