Biomedical Engineering Reference
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Fig. 3.4 Structure of the “Mead” model from [ 102 ]. R c central resistance, L r the total inertance,
R p peripheral resistance, C l lung compliance, C b bronchial tube compliance, C w wall compliance,
and C e extrathoracic compliance
Fig. 3.5 Structure of the 'extended' model from [ 29 ]. R r airway and lung resistance; R p periph-
eral resistance; L r lung inertance; C r alveolar compliance
Mechanical properties in lung and chest wall are described by the model devel-
oped originally by Mead and described later in [ 9 , 158 ]. Mead's model is an ex-
tended one-compartment model that does not allow the simulation of uneven alve-
olar ventilation (Fig. 3.4 ). In this model, R c is the central resistance, L r the total
inertance, R p peripheral resistance, C l lung compliance, C b bronchial tube compli-
ance, C w wall compliance, and C e extrathoracic compliance.
The Mead model [ 102 ] from Fig. 3.4 allows the simulation of different influences
on the respiratory mechanics (e.g. extrathoracic compliance by the mouth and the
face mask, properties of the chest wall, air leaks around face mask or endotracheal
tubes). The model is used to investigate different causes of airway obstructions and
to assess the influence of the equipment on measurements.
Recently, an extended RLC model was proposed in [ 29 ], which can be viewed ei-
ther as a simplification of the DuBois's or Mead's model, either an improvement of
the simple series RLC circuit. The model allows characterization of small airways
resistance. For the extended RLC model from Fig. 3.5 we have R r , airway and lung
resistance; R p , peripheral resistance; L r , lung inertance; C r , alveolar compliance.
This model provides a theoretical support for the observations made in experimental
 
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