Estimation of Lung Volume Change from Torso Hemicircumferences

1977 ◽  
Vol 20 (4) ◽  
pp. 808-812 ◽  
Author(s):  
R. J. Baken
Keyword(s):  
Chest Wall ◽  
Volume Change ◽  
Lung Volume ◽  
Bridge Circuit ◽  
Weighted Sum ◽  
Rib Cage ◽  
Articulatory Movements ◽  
The Subject

A technique for estimating lung volume change is described. Voltages proportional to rib cage and abdominal hemicircumferences are produced by Whitney-gage transducers in a standard bridge circuit. The weighted sum of these voltages can be adjusted to produce a good estimate of lung volume change. The instrumentation does not obstruct articulatory movements, load the chest wall, or require restraint of the subject. In addition, it is easy and inexpensive to construct.

Body Type and Speech Breathing

1986 ◽  
Vol 29 (3) ◽  
pp. 313-324 ◽  
Author(s):  
Jeannette D. Hoit ◽  
Thomas J. Hixon
Keyword(s):  
Chest Wall ◽  
Volume Change ◽  
Lung Volume ◽  
Underlying Mechanism ◽  
Relative Volume ◽  
Body Type ◽  
Tidal Breathing ◽  
Rib Cage ◽  
Musculoskeletal Development ◽  
Speech Breathing

Diameter changes of the rib cage and abdomen were recorded during tidal breathing and speech production in 12 adult male subjects grouped on the basis of prominence on three body type components: relative fatness, relative musculoskeletal development, and relative linearity. Data were charted to solve for lung volume, volume displacements of the rib cage and abdomen, and muscular mechanism. Tidal breathing differed across subject groups with regard to depth, rate, and chest wall configuration. Subjects rated high in relative fatness breathed deeper, slower, and with a greater chest wall deformation from relaxation than did other subjects: Speech breathing differed across subject groups with regard to relative volume contributions of the rib cage and abdomen, abdomeren excursions, rib cage paradoxing, and chest wall configuration. Subjects rated high in relative fatness demonstrated substantial abdomen contributions to lung volume change, large abdomen excursions, frequent rib cage paradoxing, and marked chest wall deformations from relaxation. By contrast, subjects rated high in relative linearity demonstrated large rib cage contributions to lung volume change; small abdomen excursions, and slight chest wall deformations from relaxation. Subjects rated high in relative musculoskeletal development generally represented a mixture of characteristics of the other two subject groups in their speech breathing performance. Functional differences are discussed in relation to possible underlying mechanism and inferences are drawn concerning evaluation and management of individuals with speech breathing disorders.

Three degree of freedom description of movement of the human chest wall

1986 ◽  
Vol 60 (3) ◽  
pp. 928-934 ◽  
Author(s):  
J. C. Smith ◽  
J. Mead
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Pubic Symphysis ◽  
Degree Of Freedom ◽  
Rib Cage ◽  
Additional Degree ◽  
Wall Movement ◽  
Surface Displacements ◽  
Flexion Extension ◽  
Three Degree Of Freedom

A three degree of freedom description of movement of the human chest wall is presented. In addition to the standard variables representing surface displacements of the rib cage and abdominal wall in transverse planes, the description includes a variable representing axial displacements of the chest wall associated with postural movements of the spine and pelvis. A simple technique was developed for quantifying the axial displacements using a single measurement by magnetometry of changes in the distance between a point on the anterior surface of the rib cage near the xiphisternum and a point on the abdominal surface near the pubic symphysis. It was found that axial displacements produced by either flexion-extension of the spine or rotation of the pelvis in the standing postures can be treated as a single degree of freedom. The chest wall displacements induced over the range of axial displacement examined were as large as those normally accompanying a change in lung volume on the order of 30–50% of the vital capacity. It is concluded, however, that although this additional degree of freedom can cause large chest wall displacements, it probably cannot independently change lung volume. This implies that the system is constrained so that there are only a limited number of independent modes of chest wall movement that are capable of producing significant changes in lung volume. It also suggests that the system is constructed so that lung volume can be relatively independent of certain postural distortions of the chest wall.

Regional coupling between chest wall and lung expansion during HFV: a positron imaging study

1993 ◽  
Vol 74 (5) ◽  
pp. 2242-2252 ◽  
Author(s):  
J. G. Venegas ◽  
K. Tsuzaki ◽  
B. J. Fox ◽  
B. A. Simon ◽  
C. A. Hales
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Gas Transport ◽  
Regional Scale ◽  
Regional Distribution ◽  
Imaging Study ◽  
High Frequency Ventilation ◽  
Rib Cage ◽  
Lung Expansion ◽  
Frequency Ventilation

Apparently conflicting differences between the regional chest wall motion and gas transport have been observed during high-frequency ventilation (HFV). To elucidate the mechanism responsible for such differences, a positron imaging technique capable of assessing dynamic chest wall volumetric expansion, regional lung volume, and regional gas transport was developed. Anesthetized supine dogs were studied at ventilatory frequencies (f) ranging from 1 to 15 Hz and eucapnic tidal volumes. The regional distribution of mean lung volume was found to be independent of f, but the apex-to-base ratio of regional chest wall expansion favored the lung bases at low f and became more homogeneous at higher f. Regional gas transport per unit of lung volume, assessed from washout maneuvers, was homogeneous at 1 Hz, favored the bases progressively as f increased to 9 Hz, and returned to homogeneity at 15 Hz. Interregional asynchrony (pendelluft) and right-to-left differences were small at this large regional scale. Analysis of the data at a higher spatial resolution showed that the motion of the diaphragm relative to the excursions of the rib cage decreased as f increased. These differences from apex to base in regional chest wall expansion and gas transport were consistent with a simple model including lung, rib cage, and diaphragm regional impedances and a viscous coupling between lungs and chest wall caused by the relative sliding between pleural surfaces. To further test this model, we studied five additional animals under open chest conditions. These studies resulted in a homogeneous and f-independent regional gas transport. We conclude that the apex-to-base distribution of gas transport observed during HFV is not caused by intrinsic lung heterogeneity but rather is a result of chest wall expansion dynamics and its coupling to the lung.

A model of the respiratory pump

1987 ◽  
Vol 63 (3) ◽  
pp. 951-961 ◽  
Author(s):  
D. R. Hillman ◽  
K. E. Finucane
Keyword(s):  
Chest Wall ◽  
Volume Change ◽  
Active Component ◽  
Wall Motion ◽  
Respiratory Muscles ◽  
Passive Components ◽  
Rib Cage ◽  
Lever System ◽  
Chest Wall Motion ◽  
Applied Forces

The interaction of forces that produce chest wall motion and lung volume change is complex and incompletely understood. To aid understanding we have developed a simple model that allows prediction of the effect on chest wall motion of changes in applied forces. The model is a lever system on which the forces generated actively by the respiratory muscles and passively by impedances of rib cage, lungs, abdomen, and diaphragm act at fixed sites. A change in forces results in translational and/or rotational motion of the lever; motion represents volume change. The distribution and magnitude of passive relative to active forces determine the locus and degree of rotation and therefore the effect of an applied force on motion of the chest wall, allowing the interaction of diaphragm, rib cage, and abdomen to be modeled. Analysis of moments allow equations to be derived that express the effect on chest wall motion of the active component in terms of the passive components. These equations may be used to test the model by comparing predicted with empirical behavior. The model is simple, appears valid for a variety of respiratory maneuvers, is useful in interpreting relative motion of rib cage and abdomen and may be useful in quantifying the effective forces acting on the rib cage.

Effects of lung volume, volume history, and methacholine on lung tissue viscance

1989 ◽  
Vol 66 (2) ◽  
pp. 977-982 ◽  
Author(s):  
S. T. Kariya ◽  
L. M. Thompson ◽  
E. P. Ingenito ◽  
R. H. Ingram
Keyword(s):  
Lung Tissue ◽  
Volume Change ◽  
Lung Volume ◽  
Airway Resistance ◽  
Base Line ◽  
Lung Volumes ◽  
Lung Resistance ◽  
Before And After ◽  
The Subject ◽  
Volume History

We examined the effects of lung volume change and volume history on lung resistance (RL) and its components before and during induced constriction. Eleven subjects, including three current and four former asthmatics, were studied. RL, airway resistance (Raw), and, by subtraction, tissue viscance (Vtis) were measured at different lung volumes before and after a deep inhalation and were repeated after methacholine (MCh) aerosols up to maximal levels of constriction. Vtis, which average 9% of RL at base line, was unchanged by MCh and was not changed after deep inhalation but increased directly with lung volume. MCh aerosols induced constriction by increasing Raw, which was reversed by deep inhalation in inverse proportion to responsiveness. such that the more responsive subjects reversed less after a deep breath. Responsiveness correlated directly with the degree of maximal constriction, as more responsive subjects constricted to a greater degree. These results indicate that in humans Vtis comprises a small fraction of overall RL, which is clearly volume-dependent but unchanged by MCh-induced constriction and unrelated to the degree of responsiveness of the subject.

Mechanics of the human diaphragm during voluntary contraction: statics

1978 ◽  
Vol 44 (6) ◽  
pp. 829-839 ◽  
Author(s):  
A. Grassino ◽  
M. D. Goldman ◽  
J. Mead ◽  
T. A. Sears
Keyword(s):  
Volume Change ◽  
Lung Volume ◽  
Voluntary Contraction ◽  
Electromyographic Activity ◽  
Lung Volumes ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
The Relationship ◽  
Closed Airway

We related diaphragm electromyographic activity (Edi) to transdiaphragmatic pressure (Pdi) in man during graded inspiratory efforts. Estimates of rib cage and abdominal volume displacements were based on their anteroposterior (AP) diameter changes. The diaphragm was assumed to contract isometrically when subjects performed inspiratory efforts against a closed airway at specified abdominothoracic configurations, increasing Edi and Pdi while holding lung volume and rib case and abdominal AP diameters constant. The relationship between Pdi and Edi depends primarily on abdominothoracic configuration rather than lung volume. For equal increments in lung volume, the Pdi developed at constant Edi is four to eight times more sensitive to changes in abdominal than in rib cage AP diameter. We demonstrate an isofunctional state of the diaphragm at different lung volumes, when increases in lung volume and rib cage AP diameter are compensated for by slight decreases in abdominal AP diameter, resulting in a constant relationship between Edi and Pdi. We conclude that diaphragm shortening is reflected more directly in abdominal displacement than in lung volume change.

Static features of the passive rib cage and abdomen-diaphragm

1965 ◽  
Vol 20 (6) ◽  
pp. 1187-1193 ◽  
Author(s):  
Emilio Agostoni ◽  
Piero Mognoni ◽  
Giorgio Torri ◽  
Ada Ferrario Agostoni
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Vital Capacity ◽  
Small Volume ◽  
Respiratory Muscles ◽  
Muscular Activity ◽  
Pressure Curve ◽  
Rib Cage ◽  
Expiratory Muscles ◽  
Volume Pressure Curves

The static relation between lung volume and rib cage circumference has been determined over the vital capacity range, during relaxation and activity of the respiratory muscles with open airway. At small volume the circumference is larger during relaxation; the reverse occurs at large volume. During relaxation at full expiration the cross section of the rib cage becomes more elliptical and in some subjects also greater. Hence the shape of the chest wall during muscular activity is different from that during relaxation. Because of this change of chest wall shape the outward recoil of the passive rib cage at full expiration, in the seven subjects examined, is higher than that given by the conventional volume-pressure curve during relaxation. The volume displacements of the rib cage and of the abdomen-diaphragm have been calculated and the volume-pressure curves of the passive rib cage and abdomen-diaphragm have been constructed, taking into account the changes of the chest wall shape occurring during relaxation. change of chest wall shape during relaxation; relation between lung volume and rib cage circumference during relaxation; relation between pleural pressure and rib cage circumference during relaxation; recoil of the passive rib cage; pressure exerted by the expiratory muscles at full expiration; volume-pressure curve of the passive rib cage; volume-pressure curve of the passive abdomen-diaphragm Submitted on September 14, 1964

Characteristics of Speech Breathing in Young Women

1989 ◽  
Vol 32 (3) ◽  
pp. 466-480 ◽  
Author(s):  
Megan M. Hodge ◽  
Anne Putnam Rochet
Keyword(s):  
Chest Wall ◽  
Young Women ◽  
Lung Volume ◽  
Relative Volume ◽  
Breathing Frequency ◽  
Rib Cage ◽  
Speech Breathing ◽  
Respiratory Behavior ◽  
Positive Correlations ◽  
The Relationship

Chest wall kinematic records were obtained from 10 healthy young women in the upright, seated position during resting breathing, conversation, and reading aloud. Breathing frequency, lung volume levels relative to resting end-expiratory level, and relative volume displacements of the rib cage and abdomen were measured. Compared to conversation, group results for reading revealed three differences: an increase in syllables spoken per breath, an absence of filled pauses, and a slight upward shift in end-inspiratory and end-expiratory lung volume levels. Compared to resting breathing, group results for speech revealed four differences: a background chest wall configuration characterized by a relatively larger rib cage and smaller abdomen, slight increases in breathing frequency and in lung volume expenditure, and a slight decrease in rib cage contribution to lung volume displacement. The physical characteristic most strongly associated with rib cage contribution to lung volume displacement in resting breathing was height (r = .76). In comparing the relationship between the same respiratory behavior during resting breathing and speech, a correlation of .83 was obtained for rib cage contribution to volume displacement in the two conditions and of .60 for end-inspiratory volume level in the two conditions. Somewhat weaker positive correlations were obtained for lung volume expenditure and for breathing frequency in the two conditions. Comparison of the present findings for women to those recently reported for comparable men (Holt & Hixon, 1987) revealed no remarkable differences in speech breathing characteristics. Results suggest that certain physical characteristics and task variables may have greater functional importance than gender in determining normative speech breathing behaviors.

Mechanical coupling of the rib cage, abdomen, and diaphragm through their area of apposition

1991 ◽  
Vol 70 (3) ◽  
pp. 1235-1244 ◽  
Author(s):  
B. R. Boynton ◽  
G. M. Barnas ◽  
J. T. Dadmun ◽  
J. J. Fredberg
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Abdominal Pressure ◽  
Rib Cage ◽  
Mechanical Coupling ◽  
Reported Data ◽  
Pressure Changes ◽  
Limiting Case ◽  
Point Of Departure ◽  
Very High

Although volumetric displacements of the chest wall are often analyzed in terms of two independent parallel pathways (rib cage and abdomen), Loring and Mead have argued that these pathways are not mechanically independent (J. Appl. Physiol. 53: 756-760, 1982). Because of its apposition with the diaphragm, the rib cage is exposed to two distinct pressure differences, one of which depends on abdominal pressure. Using the analysis of Loring and Mead as a point of departure, we developed a complementary analysis in which mechanical coupling of the rib cage, abdomen, and diaphragm is modeled by a linear translational transformer. This model has the advantage that it possesses a precise electrical analogue. Pressure differences and compartmental displacements are related by the transformation ratio (n), which is the mechanical advantage of abdominal over pleural pressure changes in displacing the rib cage. In the limiting case of very high lung volume, n----0 and the pathways uncouple. In the limit of very small lung volume, n----infinity and the pathways remain coupled; both rib cage and abdomen are driven by abdominal pressure alone, in accord with the Goldman-Mead hypothesis. A good fit was obtained between the model and the previously reported data for the human chest wall from 0.5 to 4 Hz (J. Appl. Physiol. 66:350-359, 1989). The model was then used to estimate rib cage, diaphragm, and abdominal elastance, resistance, and inertance. The abdomen was a high-elastance high-inertance highly damped compartment, and the rib cage a low-elastance low-inertance more lightly damped compartment. Our estimate that n = 1.9 is consistent with the findings of Loring and Mead and suggests substantial pathway coupling.

Respiratory mechanical effects of abdominal distension

1985 ◽  
Vol 58 (6) ◽  
pp. 1997-2003 ◽  
Author(s):  
R. J. Gilroy ◽  
M. H. Lavietes ◽  
S. H. Loring ◽  
B. T. Mangura ◽  
J. Mead
Keyword(s):  
Volume Change ◽  
Lung Volume ◽  
Abdominal Distension ◽  
Gastric Volume ◽  
Gastric Distension ◽  
Abdominal Pressure ◽  
Volume Changes ◽  
Rib Cage ◽  
The Face ◽  
Relaxation Characteristics

We develop a theory to predict the partitioning of a change in volume of the abdominal contents into the end-expiratory volume changes of the lung, rib cage, and anterior abdominal wall. First, we calculate the distribution of such a volume change using the relative compliances of the three compartments. We then consider the inspiratory influence of abdominal pressure on the rib cage and its effect on the distribution of this volume. We test our theory by inducing gastric distension in three experienced laboratory personnel. We instilled and subsequently withdrew 1 liter of water from a gastric balloon and examined the effects of this change in gastric volume on the relaxation characteristics of the respiratory system. The distribution of the volume change that would be expected from the observed relative compliances of the three compartments would be approximately 66% into change in lung volume, 25% into change in rib cage volume, and 9% into change in abdominal volume. Instead, in line with our predictions for acute gastric distension, approximately 33% went into decrease in lung volume, 40% into increase in rib cage volume, and 26% into increase in abdominal volume. These results suggest that the interactions among the rib cage, abdomen, and diaphragm are such as to defend against large changes in end-expiratory lung volume in the face of abdominal distension.

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