Dynamic behavior of excised dog rib cage: dependence on muscle

1991 ◽  
Vol 70 (3) ◽  
pp. 1059-1067 ◽  
Author(s):  
Y. Kikuchi ◽  
D. Stamenovic ◽  
S. H. Loring
Keyword(s):  
Dynamic Behavior ◽  
Chest Wall ◽  
Sagittal Plane ◽  
Respiratory Muscles ◽  
Midsagittal Plane ◽  
Low Frequencies ◽  
Rib Cage ◽  
Displacement Behavior ◽  
Force Displacement ◽  
Chest Wall Elastance

To assess the contribution of the rib cage to chest wall elastance and hysteresis, we measured force-displacement behavior of the isolated canine rib cage during sinusoidal forcing of the sternum in the midsagittal plane at low frequencies (0.02-2.0 Hz). Elastance of the rib cage was nearly invariant with frequency of forcing from 0.02 to 1.0 Hz and decreased with increasing amplitude. Hysteresis, the width of the force-displacement loop at middisplacement (zero displacement), was nearly constant with frequency below 1.0 Hz and increased with increasing amplitude of forcing. Removal of muscle reduced elastance and hysteresis of the rib cage substantially. The data suggest that the excised dog rib cage shows dynamic behavior similar to that of the intact human rib cage and chest wall and that respiratory muscle is responsible for a major part of the behavior of the passive chest wall. We also calculated the major and minor stiffnesses in the sagittal plane, which differed by a factor of 3-11, and their directions lay close to the dorsoventral and cephalocaudal axes, respectively. Removal of muscle reduced the stiffnesses but did not change their directions. Thus, although respiratory muscles impede motion in the sagittal plane, they do not alter its pattern.

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.

Chest wall distortion during resistive inspiratory loading

1985 ◽  
Vol 58 (5) ◽  
pp. 1646-1653 ◽  
Author(s):  
E. R. Ringel ◽  
S. H. Loring ◽  
J. Mead ◽  
R. H. Ingram
Keyword(s):  
Chest Wall ◽  
Wall Motion ◽  
Respiratory Muscles ◽  
Underlying Mechanism ◽  
Abdominal Muscles ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Circular Configuration ◽  
Chest Wall Motion ◽  
Resistive Loads

We studied six (1 naive and 5 experienced) subjects breathing with added inspiratory resistive loads while we recorded chest wall motion (anteroposterior rib cage, anteroposterior abdomen, and lateral rib cage) and tidal volumes. In the five experienced subjects, transdiaphragmatic and pleural pressures, and electromyographs of the sternocleidomastoid and abdominal muscles were also measured. Subjects inspired against the resistor spontaneously and then with specific instructions to reach a target pleural or transdiaphragmatic pressure or to maximize selected electromyographic activities. Depending on the instructions, a wide variety of patterns of inspiratory motion resulted. Although the forces leading to a more elliptical or circular configuration of the chest wall can be identified, it is difficult to analyze or predict the configurational results based on insertional and pressure-related contributions of a few individual respiratory muscles. Although overall chest wall respiratory motion cannot be readily inferred from the electromyographic and pressure data we recorded, it is clear that responses to loading can vary substantially within and between individuals. Undoubtedly, the underlying mechanism for the distortional changes with loading are complex and perhaps many are behavioral rather than automatic and/or compensatory.

scholarly journals Adaptation of lung, chest wall, and respiratory muscles during pregnancy: preparing for birth

2019 ◽  
Vol 127 (6) ◽  
pp. 1640-1650 ◽  
Author(s):  
Antonella LoMauro ◽  
Andrea Aliverti ◽  
Peter Frykholm ◽  
Daniela Alberico ◽  
Nicola Persico ◽  
...  
Keyword(s):  
Chest Wall ◽  
Respiratory System ◽  
Respiratory Muscles ◽  
Active Role ◽  
Normal Pregnancy ◽  
Abdominal Muscles ◽  
Noninvasive Methods ◽  
Rib Cage ◽  
Optoelectronic Plethysmography ◽  
Noninvasive Analysis

A plethora of physiological and biochemical changes occur during normal pregnancy. The changes in the respiratory system have not been as well elucidated, in part because radioimaging is usually avoided during pregnancy. We aimed to use several noninvasive methods to characterize the adaptation of the respiratory system during the full course of pregnancy in preparation for childbirth. Eighteen otherwise healthy women (32.3 ± 2.8 yr) were recruited during early pregnancy. Spirometry, optoelectronic plethysmography, and ultrasonography were used to study changes in chest wall geometry, breathing pattern, lung and thoraco-abdominal volume variations, and diaphragmatic thickness in the first, second, and third trimesters. A group of nonpregnant women were used as control subjects. During the course of pregnancy, we observed a reorganization of rib cage geometry, in shape but not in volume. Despite the growing uterus, there was no lung restriction (forced vital capacity: 101 ± 15% predicted), but we did observe reduced rib cage expansion. Breathing frequency and diaphragmatic contribution to tidal volume and inspiratory capacity increased. Diaphragm thickness was maintained (1st trimester: 2.7 ± 0.8 mm, 3rd trimester: 2.5 ± 0.9 mm; P = 0.187), possibly indicating a conditioning effect to compensate for the effects of the growing uterus. We conclude that pregnancy preserved lung volumes, abdominal muscles, and the diaphragm at the expense of rib cage muscles. NEW & NOTEWORTHY Noninvasive analysis of the kinematics of the chest wall and the diaphragm during resting conditions in pregnant women revealed significant changes in the pattern of thoracoabdominal breathing across the trimesters. That is, concomitant with the progressive changes of chest wall shape, the diaphragm increased its contribution to both spontaneous and maximal breathing, maintaining its thickness despite its lengthening due to the growing uterus. These results suggest that during pregnancy the diaphragm is conditioned to optimize its active role provided during parturition.

Total and local impedances of the chest wall up to 10 Hz

1990 ◽  
Vol 68 (4) ◽  
pp. 1409-1414 ◽  
Author(s):  
G. M. Barnas ◽  
K. Yoshino ◽  
J. Fredberg ◽  
Y. Kikuchi ◽  
S. H. Loring ◽  
...  
Keyword(s):  
Chest Wall ◽  
Healthy Subjects ◽  
Vital Capacity ◽  
Respiratory Muscles ◽  
Volume Changes ◽  
Impedance Measurements ◽  
Rib Cage ◽  
Gastric Pressure ◽  
Local Properties ◽  
Diameter Change

To understand how bical mechanical chest wall (CW) properties are related to those of the CW as a whole, we measured esophageal and gastric pressures, CW volume changes (measured with a head-out body plethysmograph), and anteroposterior and transverse CW diameter changes (measured with magnetometers attached to the surface) during sinusoidal forcing at the mouth (2.5% vital capacity, 0.5-10 Hz) in four healthy subjects. Total CW resistance decreased sharply as frequency rose to 3-4 Hz and remained relatively constant at higher frequencies. Total CW reactance became less negative with increasing frequency but showed no tendency to change sign. Above 2 Hz, diameters measured at different locations changed asynchronously between and within the rib cage and abdomen. “Local pathway impedances” (ratios of esophageal or gastric pressure to a rate of diameter change) showed frequency dependence similar to that of the total CW less than 3 Hz. Local pathway impedances increased during contraction of respiratory muscles acting on the pathway. We conclude that 1) total CW behavior is mainly a reflection of its individual local properties at less than or equal to 3 Hz, 2) local impedances within the rib cage or within the abdomen can change independently in some situations, and 3) asynchronies that develop within the CW during forcing greater than 3 Hz suggest that two compartments may be insufficient to describe CW properties from impedance measurements.

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

Chest wall kinematics and respiratory muscle action in walking healthy humans

1999 ◽  
Vol 87 (3) ◽  
pp. 938-946 ◽  
Author(s):  
A. Sanna ◽  
F. Bertoli ◽  
G. Misuri ◽  
F. Gigliotti ◽  
I. Iandelli ◽  
...  
Keyword(s):  
Chest Wall ◽  
Respiratory Muscle ◽  
Respiratory Muscles ◽  
Progressive Increase ◽  
Muscle Action ◽  
Rib Cage ◽  
Healthy Humans ◽  
Velocity Of Shortening ◽  
Flow Generator ◽  
Chest Wall Kinematics

We studied chest wall kinematics and respiratory muscle action in five untrained healthy men walking on a motor-driven treadmill at 2 and 4 miles/h with constant grade (0%). The chest wall volume (Vcw), assessed by using the ELITE system, was modeled as the sum of the volumes of the lung-apposed rib cage (Vrc,p), diaphragm-apposed rib cage (Vrc,a), and abdomen (Vab). Esophageal and gastric pressures were measured simultaneously. Velocity of shortening ( V di) and power [W˙di = diaphragm pressure (Pdi) × V di] of the diaphragm were also calculated. During walking, the progressive increase in end-inspiratory Vcw ( P < 0.05) resulted from an increase in end-inspiratory Vrc,p and Vrc,a ( P < 0.01). The progressive decrease ( P < 0.05) in end-expiratory Vcw was entirely due to the decrease in end-expiratory Vab ( P < 0.01). The increase in Vrc,a was proportionally slightly greater than the increase in Vrc,p, consistent with minimal rib cage distortion (2.5 ± 0.2% at 4 miles/h). The Vcw end-inspiratory increase and end-expiratory decrease were accounted for by inspiratory rib cage (RCM,i) and abdominal (ABM) muscle action, respectively. The pressure developed by RCM,i and ABM and Pdi progressively increased ( P < 0.05) from rest to the highest workload. The increase in V di, more than the increase in the change in Pdi, accounted for the increase inW˙di. In conclusion, we found that, in walking healthy humans, the increase in ventilatory demand was met by the recruitment of the inspiratory and expiratory reserve volume. ABM action accounted for the expiratory reserve volume recruitment. We have also shown that the diaphragm acts mainly as a flow generator. The rib cage distortion, although measurable, is minimized by the coordinated action of respiratory muscles.

The effect of posture on asynchronous chest wall movement in COPD

2013 ◽  
Vol 114 (8) ◽  
pp. 1066-1075 ◽  
Author(s):  
Rita Priori ◽  
Andrea Aliverti ◽  
André L. Albuquerque ◽  
Marco Quaranta ◽  
Paul Albert ◽  
...  
Keyword(s):  
Chest Wall ◽  
Body Position ◽  
Respiratory Muscles ◽  
Forced Expiratory Volume ◽  
Chronic Obstructive ◽  
Quiet Breathing ◽  
Obstructive Pulmonary Disease ◽  
Rib Cage ◽  
Copd Patients ◽  
Supine Posture

Chronic obstructive pulmonary disease (COPD) patients often show asynchronous movement of the lower rib cage during spontaneous quiet breathing and exercise. We speculated that varying body position from seated to supine would influence rib cage asynchrony by changing the configuration of the respiratory muscles. Twenty-three severe COPD patients (forced expiratory volume in 1 s = 32.5 ± 7.0% predicted) and 12 healthy age-matched controls were studied. Measurements of the phase shift between upper and lower rib cage and between upper rib cage and abdomen were performed with opto-electronic plethysmography during quiet breathing in the seated and supine position. Changes in diaphragm zone of apposition were measured by ultrasounds. Control subjects showed no compartmental asynchronous movement, whether seated or supine. In 13 COPD patients, rib cage asynchrony was noticed in the seated posture. This asynchrony disappeared in the supine posture. In COPD, upper rib cage and abdomen were synchronous when seated, but a strong asynchrony was found in supine. The relationships between changes in diaphragm zone of apposition and volume variations of chest wall compartments supported these findings. Rib cage paradox was noticed in approximately one-half of the COPD patients while seated, but was not related to impaired diaphragm motion. In the supine posture, the rib cage paradox disappeared, suggesting that, in this posture, diaphragm mechanics improves. In conclusion, changing body position induces important differences in the chest wall behavior in COPD patients.

Rib cage mechanics during quiet breathing and exercise in humans

1997 ◽  
Vol 83 (4) ◽  
pp. 1242-1255 ◽  
Author(s):  
C. M. Kenyon ◽  
S. J. Cala ◽  
S. Yan ◽  
A. Aliverti ◽  
G. Scano ◽  
...  
Keyword(s):  
Chest Wall ◽  
Respiratory Muscles ◽  
Relaxation Curve ◽  
Abdominal Pressure ◽  
Abdominal Muscles ◽  
Quiet Breathing ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Ergometer Exercise ◽  
Exercise In Humans

Kenyon, C. M., S. J. Cala, S. Yan, A. Aliverti, G. Scano, R. Duranti, A. Pedotti, and Peter T. Macklem. Rib cage mechanics during quiet breathing and exercise in humans. J. Appl. Physiol. 83(4): 1242–1255, 1997.—During exercise, large pleural, abdominal, and transdiaphragmatic pressure swings might produce substantial rib cage (RC) distortions. We used a three-compartment chest wall model ( J. Appl. Physiol. 72: 1338–1347, 1992) to measure distortions of lung- and diaphragm-apposed RC compartments (RCp and RCa) along with pleural and abdominal pressures in five normal men. RCp and RCa volumes were calculated from three-dimensional locations of 86 markers on the chest wall, and the undistorted (relaxation) RC configuration was measured. Compliances of RCp and RCa measured during phrenic stimulation against a closed airway were 20 and 0%, respectively, of their values during relaxation. There was marked RC distortion. Thus nonuniform distribution of pressures distorts the RC and markedly stiffens it. However, during steady-state ergometer exercise at 0, 30, 50, and 70% of maximum workload, RC distortions were small because of a coordinated action of respiratory muscles, so that net pressures acting on RCp and RCa were nearly the same throughout the respiratory cycle. This maximizes RC compliance and minimizes the work of RC displacement. During quiet breathing, plots of RCa volume vs. abdominal pressure were to the right of the relaxation curve, indicating an expiratory action on RCa. We attribute this to passive stretching of abdominal muscles, which more than counterbalances the insertional component of transdiaphragmatic pressure.

Rib cage versus abdominal displacement in rabbits during forced oscillations to 30 Hz

1987 ◽  
Vol 63 (1) ◽  
pp. 309-314 ◽  
Author(s):  
B. R. Boynton ◽  
J. J. Fredberg ◽  
B. G. Buckley ◽  
I. D. Frantz
Keyword(s):  
Chest Wall ◽  
Series Resistance ◽  
Relative Displacement ◽  
Forced Oscillations ◽  
Volume Changes ◽  
Wall Model ◽  
Large Measure ◽  
Low Frequencies ◽  
Rib Cage ◽  
Experimental Findings

We measured relative displacement of the rib cage (RC) and abdomen (ABD) in 12 anesthetized rabbits during forced oscillations. Sinusoidal volume changes were delivered through a tracheostomy at frequencies from 0.5 to 30 Hz and measured by body plethysmography. Displacements of the RC and ABD were measured by inductive plethysmography. During oscillation at fixed tidal volume (VT = 1.3 ml/kg) the ratio ABD/RC, normalized to unity at 0.5 Hz, was 0.88 +/- 0.06 at 2 Hz and increased to 1.28 +/- 0.13 at 6 Hz (P less than 0.01). As frequency increased further ABD/RC fell sharply but between 20 and 30 Hz reached a plateau of 0.17 +/- 0.02 (P less than 0.001). Displacements of RC and ABD were nearly synchronous from 0.5 to 2 Hz, but as frequency increased ABD lagged RC progressively, reaching a phase difference of 90 degrees between 6 and 8 Hz and 180 degrees between 16 and 20 Hz. In six additional rabbits we measured chest wall displacements while varying VT from 0.5 to 3.7 ml/kg. ABD/RC was independent of VT at low frequencies (less than or equal to 6 Hz) but fell sharply with increasing VT at the higher frequencies. We interpreted these findings using a chest wall model having an RC compartment whose displacements are governed primarily by a nonlinear compliance, in parallel with an ABD compartment whose displacements are governed by a series resistance, inertance, and in addition a nonlinear compliance. The experimental findings are in large measure accounted for by such a model if the degree of nonlinearity of ABD and RC compliances are comparable.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of rib cage and abdominal restriction on total respiratory resistance and reactance

1986 ◽  
Vol 61 (5) ◽  
pp. 1736-1740 ◽  
Author(s):  
J. A. van Noord ◽  
M. Demedts ◽  
J. Clement ◽  
M. Cauberghs ◽  
K. P. Van de Woestijne
Keyword(s):  
Chest Wall ◽  
Respiratory Resistance ◽  
Low Frequencies ◽  
Rib Cage ◽  
Lung Capacity ◽  
Residual Capacity ◽  
The Subject ◽  
A Minor ◽  
Male Subjects ◽  
Airway Conductance

In 14 healthy male subjects we studied the effects of rib cage and abdominal strapping on lung volumes, airway resistance (Raw), and total respiratory resistance (Rrs) and reactance (Xrs). Rib cage, as well as abdominal, strapping caused a significant decrease in vital capacity (respectively, -36 and -34%), total lung capacity (TLC) (-31 and -27%), functional residual capacity (FRC) (-28 and -28%), and expiratory reserve volume (-40 and -48%) and an increase in specific airway conductance (+24 and +30%) and in maximal expiratory flow at 50% of control TLC (+47 and +42%). The decrease of residual volume (RV) was significant (-12%) with rib cage strapping only. Abdominal strapping resulted in a minor overall increase in Rrs, whereas rib cage strapping produced a more marked increase at low frequencies; thus a frequency dependence of Rrs was induced. A similar pattern, but with lower absolute values, of Rrs was obtained by thoracic strapping when the subject was breathing at control FRC. Xrs was decreased, especially at low frequencies, with abdominal strapping and even more with thoracic strapping; thus the resonant frequency of the respiratory system was shifted toward higher frequencies. Partitioning Rrs and Xrs into resistance and reactance of lungs and chest wall demonstrated that the different effects of chest wall and abdominal strapping on Rrs and Xrs reflect changes mainly of chest wall mechanics.

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