BIOFLUID DYNAMICS OF THE HUMAN RESPIRATORY SYSTEM

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BIOFLUID DYNAMICS OF THE HUMAN RESPIRATORY SYSTEM
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The future belongs to those who believe in the
beauty of their dreamsEleanor Roosevelt
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Contributors

• from left to right
• 1. Hong Guo 3. Tejas Choksi,
• 2. Amaury Pita 4.Julian Bedoya

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Description of The Respiratory System

• www.lungusa.org

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Functions of Biofluids in The Respiratory System

• General functions of blood
• Transportation
• pH regulation and ion composition
• Restriction of fluid losses at injury sites
• Defense against toxins and pathogens
• Stabilization of body temperature

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Composition of Inhaled and Exhaled Gases

• users.tpg.com.au

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Alveolar Organization
Martini, 2001
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Mechanics of Ventilation

• The change in
• alveolar ventilation
• Is inversely related to changes in arterial PaCO2
  and
• Directly proportional to total body CO2
  production.

• www.biosci.ohiostate.edu

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• Effects of pH and partial pressure of oxygen on
  the percent saturation of hemoglobin

www.biosci.ohiostate.edu
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• Change in extra cellular pH due to change in
  alveolar ventilation rate

www.ursai.kcom.edu
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Oxygen Transport

• Oxygen-hemoglobin saturation curve

www.biosci.ohiostate.edu
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Carbon Dioxide Transport
www.ursai.kcom.edu
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Pulmonary Volumes and Capacities
www.biosci.ohiostate.edu
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Conceptual Model of Respiratory System
Menon et.al 1984
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Pulmonary Cellular Mechanics

• Changes in lung volume affects Airflow Aspects
  of lung metabolism Function and growth.
• Mechanical forces may be secondary to gradients
  in gravity, motion, osmotic forces and
  interactions between cells and/or matrix
  components.
• Cells within a complex 3-D structure such as the
  lung are likely to be subjected to different
• physical forces.

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Respiratory Fluid Mechanics

• Continuity Equation
• Navier-Stokes Equation
• (for 1- D, incompressible fluid for a
  constant viscosity)

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• Laminar velocity profile for fully developed flow

Fung, 1990
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• Glottis shown during inspiration (a) and
  expiration (b)

Renotte,et.al 2000
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Pressure Drop As a Function of Airway Generation

• Filled circles represent actual values.
• Open circles represent values predicted by
• Poiseuilles Law.

Fung, 1990
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Gas Flow In Bifurcation

• 2 - D plane schematic of CFD model used for flow
  in bifurcation

Liu, et.al 2002
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• Dean vortices observed during flow in a curved
  bifurcation

Caro, et.al 1978
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Velocity Profiles for Pulsatile Flow vs.
Womersley number

• Womersley number is defined as
• Where
• ? Circular frequency
• ? Kinematics
• viscosity

Caro, et.al 1978
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Flow Visualization

• The flow patterns at peak systole in the main
  pulmonary arteries

Sung, et.al 1998
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CFD for Respiratory System

• CFD model of the human nasal cavity

www.wmrc.com
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Mechanical Ventilation

• Mechanical Ventilator Volume Ventilators, High
  Frequency Ventilators, Pressure Ventilators

www.addenbrookes.org.uk
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Direct Contact and Membrane Oxygenators
Direct Contact
Membrane
www.vuse.vanderbilt.edu
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• HeartLung Machine with An Oxygenator
• Connected to The Patient

www.vuse.vanderbilt.edu
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Recent Advances

• IMO (Intravenous or Impantable Membrane
  Oxygenator)
• artificial lung device

www.vuse.vanderbilt.edu
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Artificial Impantable Lung
www.vuse.vanderbilt.edu
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Thank you
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The future belongs to those who believe in the
beauty of their dreamsEleanor Roosevelt