Effect of gravity on chest wall mechanics

2002 ◽  
Vol 92 (2) ◽  
pp. 709-716 ◽  
Author(s):  
D. Bettinelli ◽  
C. Kays ◽  
O. Bailliart ◽  
A. Capderou ◽  
P. Techoueyres ◽  
...  
Keyword(s):  
Linear System ◽  
Chest Wall ◽  
Lung Volume ◽  
Vital Capacity ◽  
Pressure Curve ◽  
Parabolic Flights ◽  
Chest Wall Mechanics ◽  
Exponential Decrease ◽  
Volume Range

Chest wall mechanics was studied in four subjects on changing gravity in the craniocaudal direction (Gz) during parabolic flights. The thorax appears very compliant at 0 Gz: its recoil changes only from −2 to 2 cmH2O in the volume range of 30–70% vital capacity (VC). Increasing Gz from 0 to 1 and 1.8 Gzprogressively shifted the volume-pressure curve of the chest wall to the left and also caused a fivefold exponential decrease in compliance. For lung volume <30% VC, gravity has an inspiratory effect, but this effect is much larger going from 0 to 1 Gz than from 1 to 1.8 Gz. For a volume from 30 to 70% VC, the effect is inspiratory going from 0 to 1 Gz but expiratory from 1 to 1.8 Gz. For a volume greater than ∼70% VC, gravity always has an expiratory effect. The data suggest that the chest wall does not behave as a linear system when exposed to changing gravity, as the effect depends on both chest wall volume and magnitude of Gz.

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

Modulation of chest wall intermuscular coherence: effects of lung volume excursion and transcranial direct current stimulation

2013 ◽  
Vol 110 (3) ◽  
pp. 680-687 ◽  
Author(s):  
Corey R. Tomczak ◽  
Krista R. Greidanus ◽  
Carol A. Boliek
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Vital Capacity ◽  
Healthy Adults ◽  
Cortical Control ◽  
Tidal Breathing ◽  
Wall Area ◽  
Speech Breathing ◽  
Intermuscular Coherence ◽  
Chest Wall Kinematics

Chest wall muscle recruitment varies as a function of the breathing task performed. However, the cortical control of the chest wall muscles during different breathing tasks is not known. We studied chest wall intermuscular coherence during various task-related lung volume excursions in 10 healthy adults (34 ± 15 yr; 2 men, 8 women) and determined if transcranial direct current stimulation (tDCS) could modulate chest wall intermuscular coherence during these tasks. Simultaneous assessment of regional intercostal and oblique electromyographic activity was measured while participants performed standardized tidal breathing, speech, maximum phonation, and vital capacity tasks. Lung volume and chest wall kinematics were determined using variable inductance plethysmography. We found that chest wall area of intermuscular coherence was greater during tidal and speech breathing compared with phonation and vital capacity (all P < 0.05) and between tidal breathing compared with speech breathing ( P < 0.05). Anodal tDCS increased chest wall area of intermuscular coherence from 0.04 ± 0.09 prestimulation to 0.18 ± 0.19 poststimulation for vital capacity ( P < 0.05). Sham tDCS and cathodal tDCS had no effect on coherence during lung volume excursions. Chest wall kinematics were not affected by tDCS. Our findings indicate that lung volume excursions about the midrange of vital capacity elicit a greater area of chest wall intermuscular coherence compared with lung volume excursions spanning the entire range of vital capacity in healthy adults. Our findings also demonstrate that brief tDCS may modulate the cortical control of the chest wall muscles in a stimulation- and lung volume excursion task-dependent manner but does not affect chest wall kinematics in healthy adults.

Gravity effects on regional lung ventilation determined by functional EIT during parabolic flights

2001 ◽  
Vol 91 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Inéz Frerichs ◽  
Taras Dudykevych ◽  
José Hinz ◽  
Marc Bodenstein ◽  
Günter Hahn ◽  
...  
Keyword(s):  
Lung Volume ◽  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Lung Ventilation ◽  
Tidal Breathing ◽  
Parabolic Flights ◽  
Regional Lung ◽  
Residual Capacity ◽  
The Right ◽  
Regional Lung Ventilation

Gravity-dependent changes of regional lung function were studied during normogravity, hypergravity, and microgravity induced by parabolic flights. Seven healthy subjects were followed in the right lateral and supine postures during tidal breathing, forced vital capacity, and slow expiratory vital capacity maneuvers. Regional 1) lung ventilation, 2) lung volumes, and 3) lung emptying behavior were studied in a transverse thoracic plane by functional electrical impedance tomography (EIT). The results showed gravity-dependent changes of regional lung ventilation parameters. A significant effect of gravity on regional functional residual capacity with a rapid lung volume redistribution during the gravity transition phases was established. The most homogeneous functional residual capacity distribution was found at microgravity. During vital capacity and forced vital capacity in the right lateral posture, the decrease in lung volume on expiration was larger in the right lung region at all gravity phases. During tidal breathing, the differences in ventilation magnitudes between the right and left lung regions were not significant in either posture or gravity phase. A significant nonlinearity of lung emptying was determined at normogravity and hypergravity. The pattern of lung emptying was homogeneous during microgravity.

Partitioning of Lung and Chest-wall Mechanics Before and After Lung-volume-reduction Surgery

1998 ◽  
Vol 158 (1) ◽  
pp. 306-310 ◽  
Author(s):  
AMAL JUBRAN ◽  
FRANCO LAGHI ◽  
MALINDA MAZUR ◽  
SAIRAM PARTHASARATHY ◽  
EDWARD R. GARRITY ◽  
...  
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Volume Reduction ◽  
Lung Volume Reduction Surgery ◽  
Lung Volume Reduction ◽  
Chest Wall Mechanics ◽  
Before And After

Effects of increased +Gz on chest wall mechanics in humans

1995 ◽  
Vol 78 (3) ◽  
pp. 997-1003 ◽  
Author(s):  
M. Estenne ◽  
A. Van Muylem ◽  
W. Kinnear ◽  
M. Gorini ◽  
V. Ninane ◽  
...  
Keyword(s):  
Chest Wall ◽  
Minute Ventilation ◽  
Normal Subjects ◽  
Abdominal Pressure ◽  
Transdiaphragmatic Pressure ◽  
Parabolic Flights ◽  
Linear Effect ◽  
Chest Wall Mechanics ◽  
Abdominal Compliance ◽  
Tidal Changes

We studied the effects of head-to-foot acceleration (+Gz) on chest wall mechanics in five normal subjects seated in a human centrifuge. Results were compared with those previously obtained in the same subjects in microgravity during parabolic flights. In all subjects, end-expiratory abdominal pressure (Pga) and volume (Vab) increased with Gz. On average, end-expiratory Pga increased from 7.4 +/- 1.7 cmH2O at + 1 Gz to 14.9 +/- 2.8 cmH2O at + 3 Gz and end-expiratory Vab increased by 0.32 +/- 0.06 liter between + 1 and + 3 Gz. On the other hand, the abdominal contribution to tidal volume (Vab/VT) and abdominal compliance decreased from 34.7 +/- 5.9% and 52 +/- 6 ml/cmH2O at + 1 Gz to 29.3 +/- 5.1% and 26 +/- 4 ml/cmH2O at + 3 Gz, respectively. Changes in end-expiratory Pga were linear between 0 and + 3 Gz, but changes in end-expiratory Vab, Vab/VT, and abdominal compliance were greater in microgravity than in hypergravity. In contrast to weightlessness, which did not alter minute ventilation and tidal changes in Pga and transdiaphragmatic pressure, these variables increased with increasing Gz. These results indicate that, although changes in Gz have a linear effect on abdominal transmural pressure, hypergravity and weightlessness do not have symmetrical effects on chest wall mechanics.

scholarly journals STUDIES OF LUNG VOLUME

1918 ◽  
Vol 27 (1) ◽  
pp. 87-94 ◽  
Author(s):  
A. Garvin ◽  
Christen Lundsgaard ◽  
Donald D. Van Slyke
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Vital Capacity ◽  
Normal Lung ◽  
Lung Volumes ◽  
Total Lung Volume ◽  
Normal Limits ◽  
Male Patients ◽  
Total Capacity ◽  
Residual Air

1. The total capacity, middle capacity, and residual air have been determined in 31 adult male patients suffering from tuberculosis of the lungs. 2. The chest volumes have been determined in each case and the normal lung volumes calculated by means of the ratios worked out in a previous paper. 3. In nine patients with incipient tuberculosis, the total lung volume was found within normal limits, whereas the vital capacity was diminished as a result of an increased residual air. The increase in the residual air was due to less complete expiration, caused partly by diminished movement of the diaphragm, partly by diminished compression of the chest wall. The diminished movement of the diaphragm was, as a rule, most marked on the most affected side. Whether these decreased movements are due to a reflex or to stiffness of the lung tissue we could not determine. The middle capacity was found practically normal. 4. In twenty-two cases of moderately advanced, and advanced tuberculosis, the total lung volume was in most cases markedly decreased. The vital capacity was substantially decreased, principally as a result of the diminished total capacity. The residual air was, as a rule, normal, although in a few cases an increase in residual air also contributed to the decrease in the vital capacity. The middle capacity, on which we do not want to put too much stress, was normal in some patients and considerably diminished in others.

Relation between changes of rib cage circumference and lung volume

1965 ◽  
Vol 20 (6) ◽  
pp. 1179-1186 ◽  
Author(s):  
Emilio Agostoni ◽  
Piero Mognoni ◽  
Giorgio Torri ◽  
Franco Saracino
Keyword(s):  
Volume Change ◽  
Lung Volume ◽  
Supine Position ◽  
Vital Capacity ◽  
Geometrical Approach ◽  
Total Change ◽  
Lung Volumes ◽  
Rib Cage ◽  
Average Change ◽  
Volume Range

The static relation between lung volume and rib cage circumference has been determined over the vital capacity range in standing, sitting, and supine position. The average change of circumference over the expiratory reserve volume in the three positions was, respectively, 20.7, 30.5, and 26.5% of the total change. The patterns of the volume-circumference curves have been discussed in terms of the different mechanical features of the rib cage and of the abdomen-diaphragm according to the lung volume and the position. The volume displacement of the rib cage, DeltaVrc, and of the abdomen-diaphragm, DeltaV(ab + di), at different lung volumes, have been calculated by a geometrical approach. These results agreed with determinations of DeltaV(ab + di) over the tidal volume range obtained by immobilizing the rib cage at resting volume. Over the expiratory reserve volume, DeltaVrc, in the three positions, was, respectively, 18.9, 27.8, and 40.7% of the lung volume change; over the vital capacity, DeltaVrc was, respectively, 39.6, 37.1, and 41.1. effect of position and lung volume on the rib cage circumference; volume displacement of the rib cage and of the abdomen-diaphragm Submitted on September 14, 1964

Effect of respiratory muscle tension on lung volume

1992 ◽  
Vol 73 (6) ◽  
pp. 2283-2288 ◽  
Author(s):  
T. A. Wilson ◽  
A. De Troyer
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Airway Pressure ◽  
Linear Prediction ◽  
Muscle Tension ◽  
Muscle Length ◽  
Respiratory Muscles ◽  
Active Tension ◽  
Airway Opening ◽  
Measured Change

The chest wall is modeled as a linear system for which the displacements of points on the chest wall are proportional to the forces that act on the chest wall, namely, airway opening pressure and active tension in the respiratory muscles. A standard theorem of mechanics, the Maxwell reciprocity theorem, is invoked to show that the effect of active muscle tension on lung volume, or airway pressure if the airway is closed, is proportional to the change of muscle length in the relaxation maneuver. This relation was tested experimentally. The shortening of the cranial-caudal distance between a rib pair and the sternum was measured during a relaxation maneuver. These data were used to predict the respiratory effect of forces applied to the ribs and sternum. To test this prediction, a cranial force was applied to the rib pair and a caudal force was applied to the sternum, simulating the forces applied by active tension in the parasternal intercostal muscles. The change in airway pressure, with lung volume held constant, was measured. The measured change in airway pressure agreed well with the prediction. In some dogs, nonlinear deviations from the linear prediction occurred at higher loads. The model and the theorem offer the promise that existing data on the configuration of the chest wall during the relaxation maneuver can be used to compute the mechanical advantage of the respiratory muscles.

Chest wall muscle atrophy as a contributory factor for forced vital capacity decline in systemic sclerosis-associated interstitial lung disease

Rheumatology ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 250-255
Author(s):  
Takashi Nawata ◽  
Yuichiro Shirai ◽  
Mikito Suzuki ◽  
Masataka Kuwana
Keyword(s):  
Interstitial Lung Disease ◽  
Lung Disease ◽  
Chest Wall ◽  
Muscle Atrophy ◽  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Pulmonary Function Tests ◽  
Potential Contribution ◽  
Muscle Area ◽  
Chest Wall Muscle

Abstract Objective To investigate the potential contribution of accessory respiratory muscle atrophy to the decline of forced vital capacity (FVC) in patients with SSc-associated interstitial lung disease (ILD). Methods This single-centre, retrospective study enrolled 36 patients with SSc-ILD who underwent serial pulmonary function tests and chest high-resolution CT (HRCT) simultaneously at an interval of 1–3 years. The total extent of ILD and chest wall muscle area at the level of the ninth thoracic vertebra on CT images were evaluated by two independent evaluators blinded to the patient information. Changes in the FVC, ILD extent, and chest wall muscle area between the two measurements were assessed in terms of their correlations. Multiple regression analysis was conducted to identify the independent contributors to FVC decline. Results Interval changes in FVC and total ILD extent were variable among patients, whereas chest wall muscle area decreased significantly with time (P=0.0008). The FVC change was negatively correlated with the change in ILD extent (r=−0.48, P=0.003) and was positively correlated with the change in the chest wall muscle area (r = 0.53, P=0.001). Multivariate analysis revealed that changes in total ILD extent and chest wall muscle area were independent contributors to FVC decline. Conclusion In patients with SSc-ILD, FVC decline is attributable not only to the progression of ILD but also to the atrophy of accessory respiratory muscles. Our findings call attention to the interpretation of FVC changes in patients with SSc-ILD.

The Effects of Increased Abdominal Pressure on Lung and Chest Wall Mechanics During Laparoscopic Surgery

1995 ◽  
Vol 81 (4) ◽  
pp. 744-750 ◽  
Author(s):  
Brenda G. Fahy ◽  
George M. Barnas ◽  
John L. Flowers ◽  
Sheryl E. Nagle ◽  
Mary J. Njoku
Keyword(s):  
Laparoscopic Surgery ◽  
Chest Wall ◽  
Abdominal Pressure ◽  
Chest Wall Mechanics
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