Chest wall shape during forced expiratory maneuvers

1981 ◽  
Vol 50 (1) ◽  
pp. 84-93 ◽  
Author(s):  
C. G. Melissinos ◽  
M. Goldman ◽  
E. Bruce ◽  
E. Elliott ◽  
J. Mead
Keyword(s):  
Volume Change ◽  
Vital Capacity ◽  
Vertical Motion ◽  
Normal Subjects ◽  
Sectional Area ◽  
Potential Mechanism ◽  
Cross Sectional ◽  
Rib Cage ◽  
Abdominal Shape ◽  
Shape Changes

Abdominothoracic shape during the forced vital capacity was studied in 10 normal subjects using magnetometers to monitor anteroposterior diameters at the level of the manubrium, xiphoid, and epigastrium, lateral rib cage diameter at the xiphoid level, and vertical motion of the rib cage. Thoracic cross-sectional area change at the xiphoid level was found to lag lung volume change, due to an early paradoxical increase (or lack of change), of lower anteroposterior rib cage diameter. To the extent that the resulting rib cage deformation can influence the pleural pressure gradient, the observed shape changes provide a potential mechanism for early preferential emptying of the upper lobes and later more homogeneous emptying in forced, compared to slow, vital capacity maneuvers. Comparisons of shape changes during Valsalva and abdominal expiratory ("expulsive") maneuvers suggest that lower rib cage deformation may not simply be due to the action of rib cage muscles affecting predominantly the lateral rib cage but rather the results of diaphragmatic activity and the influence of abdominal shape on the lower rib cage.

Respiratory cross-sectional area-flux measurements of the human chest wall

1990 ◽  
Vol 68 (4) ◽  
pp. 1605-1614 ◽  
Author(s):  
R. Sartene ◽  
P. Martinot-Lagarde ◽  
M. Mathieu ◽  
A. Vincent ◽  
M. Goldman ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Tidal Volume ◽  
Chest Wall ◽  
Normal Subjects ◽  
Cross Sectional Area ◽  
7 Tesla ◽  
Sectional Area ◽  
Cross Sectional ◽  
Rib Cage ◽  
Orientation Effects

A new device that utilizes the voltages induced in separate coils encircling the rib cage and abdomen by a magnetic field is described for measurement of cross-sectional areas of the human chest wall (rib cage and abdomen) and their variation during breathing. A uniform magnetic field (1.4 X 10(-7) Tesla at 100 kHz) is produced by generating an alternating current at 100 kHz in two square coils, 1.98 m on each side, parallel to the planes of the areas to be measured and placed symmetrically cephalad and caudad to these planes at a mean distance of 0.53 m. We demonstrated that the accuracy of the device on well-defined surfaces (squares, circles, rectangles, ellipses) was within 1% in all cases. Observed errors are due primarily to small inhomogeneities of the magnetic field and variation of the orientation of the coil relative to the field. Using a second magnetic field (80 kHz) perpendicular to the first, we measured the errors due to nonparallel orientation during quiet breathing and inspiratory capacity maneuvers. In 10 normal subjects, orientation effects were less than 2% for the rib cage and less than 0.7% for the abdomen. In five of these subjects, orientation effects at functional residual capacity in lateral and seated postures were generally less than or equal to 5%, but estimated tidal volume during spontaneous breathing was comparable to measurements in the supine posture. In five curarized patients, we assessed the linearity of volume-motion relationships of the rib cage and abdomen, comparing cross-sectional area and circumference measurements. Departures from linearity using cross-sectional areas were only one-third of those using circumferences. In seven normal subjects we compared cross-sectional area measurements with respiratory inductive plethysmography (RIP) and found comparable estimates of lung volume change over a wide range of relative rib cage contributions to tidal volume (-5 to 105%), with slightly higher standard deviations for the RIP (SD = 10% for RIP; SD = 4% for cross-sectional area).

Relationship between lung volume and tracheal area as assessed by acoustic reflection

1988 ◽  
Vol 64 (3) ◽  
pp. 1050-1054 ◽  
Author(s):  
L. J. Brooks ◽  
P. J. Byard ◽  
R. C. Helms ◽  
J. M. Fouke ◽  
K. P. Strohl
Keyword(s):  
Young Adults ◽  
Body Size ◽  
Lung Disease ◽  
Lung Volume ◽  
Vital Capacity ◽  
Significant Positive Correlation ◽  
Lung Parenchyma ◽  
Sectional Area ◽  
Cross Sectional ◽  
Acoustic Reflection

To determine whether airway size correlates with measures of lung or body size, we used the acoustic reflection technique to calculate tracheal cross-sectional area in 103 healthy young adults. Men have significantly larger tracheas than women [2.48 ± 0.08 vs. 1.91 ± 0.05 (SE) cm2, P less than 0.001]. Within each sex, there is no correlation between tracheal size and body size or maximal expiratory flows. There is a significant positive correlation between tracheal area and vital capacity in males only (r = 0.36, P less than 0.01). These results support the concept of dysanapsis, relatively independent growth of the airways and lung parenchyma, as well as sex-related differences in airway size and growth. Inherent airway size may be a factor in the development and/or progression of lung disease.

Alveolar pressure-airflow characteristics in humans breathing air, He-O2, and SF6-O2

1981 ◽  
Vol 51 (4) ◽  
pp. 1033-1037 ◽  
Author(s):  
A. S. Slutsky ◽  
J. M. Drazen ◽  
C. F. O'Cain ◽  
R. H. Ingram
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Coefficient Of Friction ◽  
Transpulmonary Pressure ◽  
Normal Subjects ◽  
Sectional Area ◽  
Alveolar Pressure ◽  
Flow Conditions ◽  
Cross Sectional ◽  
The Coefficient Of Friction

In a system of rigid tubes under steady flow conditions, the coefficient of friction [CF = 2 delta P/(rho V2/A2)] (where delta P is pressure drop, rho is density, V is flow, and A is cross-sectional area) should be a unique function of Reynolds' number (Re). Recently it has been shown that at any given Re, the value of CF using transpulmonary pressure (PL) was lower when breathing He-O2 compared with air (Lisboa et al., J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 48: 878–885, 1980). One explanation for this discontinuity is that PL includes the pressure drop due to tissue viscance, which is independent of V, and thus would lead to an overestimate of CF on air compared with He-O2 at any Re. We tested this hypothesis by measuring V related to alveolar pressure, rather than PL, in normal subjects breathing air, He-O2, and SF6-O2. In each subject, for a given Re, CF was greatest breathing SF6-O2 and lowest breathing He-O2, similar to results using PL. Thus tissue viscance is not the sole cause of the discontinuous plot of CF vs. Re, and this phenomenon must be due to other factors, such as changing geometry or nonsteady behavior.

Mechanical coupling of upper and lower canine rib cages and its functional significance

1988 ◽  
Vol 64 (2) ◽  
pp. 620-626 ◽  
Author(s):  
T. X. Jiang ◽  
M. Demedts ◽  
M. Decramer
Keyword(s):  
Nerve Stimulation ◽  
Phrenic Nerve ◽  
Cross Sectional Area ◽  
Abdominal Pressure ◽  
Sectional Area ◽  
Phrenic Nerve Stimulation ◽  
Cross Sectional ◽  
Rib Cage ◽  
Lower Canine ◽  
The Relationship

We studied rib cage distortability and reexamined the mechanical action of the diaphragm and the rib cage muscles in six supine anesthetized dogs by measuring changes in upper rib cage cross-sectional area (Aurc) and changes in lower rib cage cross-sectional area (Alrc) and the respective pressures acting on them. During quiet breathing in the intact animal the rib cage behaved as a unit (Aurc: 14.6 +/- 7.9 vs. Alrc: 15.1 +/- 9.6%), whereas considerable distortions of the rib cage occurred during breathing after bilateral phrenicotomy (Aurc: 21.0 +/- 5.1 vs. Alrc: 7.0 +/- 4.8%). These distortions were even more pronounced during phrenic nerve stimulation and separate stimulation of the costal and crural parts of the diaphragm (e.g., phrenic nerve stimulation; Aurc: -7.1 +/- 5.1 vs. Alrc: 6.9 +/- 3.5%). During the latter maneuvers the upper rib cage deflated along the relationship between upper rib cage dimensions and pleural pressure obtained during passive deflation, whereas the lower rib cage inflated close to the relationship between lower rib cage dimensions and abdominal pressure obtained during passive inflation. The latter relationship is expected to differ between costal and crural stimulation, since costal action has both an appositional and insertional component and crural action only has an appositional component. The difference between costal and crural stimulation, however, was relatively small, and the slopes were only slightly steeper for the costal than for the crural stimulation (2.9 +/- 1.2 vs. 2.2 +/- 1.0%.(ABSTRACT TRUNCATED AT 250 WORDS)

Opening the Nasal Valve with External Dilators Reduces Congestive Symptoms in Normal Subjects

2005 ◽  
Vol 19 (2) ◽  
pp. 215-219 ◽  
Author(s):  
Jenny Latte ◽  
David Taverner
Keyword(s):  
Visual Analog Scale ◽  
Nasal Congestion ◽  
Normal Subjects ◽  
Cross Sectional Area ◽  
Ordinal Scale ◽  
Sectional Area ◽  
Nasal Valve ◽  
Analog Scale ◽  
Cross Sectional ◽  
Valve Area

Background We examined whether the use of two different external nasal dilator devices influenced the size of the nasal valve area and symptoms of nasal congestion. Methods This was a randomized blind-allocation, open three-way crossover study of Breathe Right, Side Strip Nasal Dilators, and placebo. We studied 12 healthy subjects (10 female, 2 male; age range 26–56 years). Measures of total volume and total minimum cross-sectional area were collected. Subjective symptoms were collected using a visual analog scale and an ordinal scale. Results With both products, there was significant increase in the size of the minimum cross-sectional area compared to placebo, p = 0.004. This is supported by the decrease in the subjective reports of congestion; on the visual analog scale, compared to placebo p = 0.012 and the ordinal scale, compared to placebo, p = 0.004. Conclusion Both devices significantly increase the size of the nasal valve area and reduce congestion in normal subjects.

An Anechoic Space at the Carpal Tunnel Inlet is a Consistent Ultrasonographic Entity which Accommodates Tendon Displacement during Finger Flexion

2016 ◽  
Vol 21 (02) ◽  
pp. 222-228
Author(s):  
Bing Howe Lee ◽  
Chin Hock Goh ◽  
Amitabha Lahiri
Keyword(s):  
Median Nerve ◽  
Carpal Tunnel ◽  
Prevalence Rate ◽  
Normal Subjects ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Finger Flexion ◽  
Normal Individuals ◽  
Asymptomatic Volunteers

Background: We consistently observed the presence of anechoic spaces on standard ultrasonographic imaging of the carpal tunnel inlet in normal subjects. These spaces change in size during finger flexion and have not been characterized in a large sample of normal individuals. Ultrasonographic quantification of these spaces may indicate the available space in the region of the carpal tunnel, which allows the normal motion of tendons and the median nerve. Methods: Transverse ultrasonographic images of the carpal tunnel inlet from 33 asymptomatic volunteers were obtained at Position A (fingers in extension) and B (fingers in flexion). Cross-sectional area (CSA), perimeter and position of anechoic space relative to median nerve were recorded. Results: Analysis showed a 75.4% prevalence rate of a single anechoic space. Two discrete patterns were observed. 89.1% had a decrease in CSA and perimeter of anechoic space from Position A to B while 10.9% exhibited an increase. Mean position of the anechoic space is ulnar (7.49 ± 3.57 mm) and dorsal (2.18 ± 1.28 mm) to the median nerve. Conclusions: A consistent anechoic space at the carpal tunnel inlet is seen in 75.4% of normal hands and can be quantified (cross sectional area 11.75 ± 7.36 mm2). It allows for the accommodation of flexor tendons during finger flexion.

Human rib cage distortability

1996 ◽  
Vol 81 (1) ◽  
pp. 437-447 ◽  
Author(s):  
K. Chihara ◽  
C. M. Kenyon ◽  
P. T. Macklem
Keyword(s):  
Normal Subjects ◽  
Cross Sectional ◽  
Transdiaphragmatic Pressure ◽  
Rib Cage ◽  
Gastric Pressure ◽  
The Difference ◽  
Normal Men

In five normal men, we divided the rib cage into lung-apposed [pulmonary rib cage (RCp)] and diaphragm-apposed [abdominal rib cage (RCab)] compartments and calculated their absolute cross-sectional areas (Arc,p and Arc,ab) by anteroposterior and lateral dimensions measured by magnetometry. Distortion was quantified as the displacement of RCp and RCab produced by diaphragmatic twitches away from the relaxed configuration. We measured transdiaphragmatic pressure as the difference between gastric and esophageal pressures. Distortability was expressed as percent distortion per transdiaphragmatic pressure and varied among individuals from 0.02 to 0.23%/cmH2O. The pressure acting to restore the distorted rib cage back to its relaxed shape (Plink) varied from 0.1 to 31.3 cmH2O/%distortion. Distortion correlated positively (r = 0.92) and Plink per percent distortion negatively (r = -0.90) with RCab compliance during the relaxation maneuver (delta Arc, ab/delta gastric pressure). We conclude that rib cage distortability varies widely among normal subjects and is closely linked to RCab compliance.

scholarly journals Volume displaced by diaphragm motion in emphysema

2001 ◽  
Vol 91 (5) ◽  
pp. 1913-1923 ◽  
Author(s):  
Bhajan Singh ◽  
Peter R. Eastwood ◽  
Kevin E. Finucane
Keyword(s):  
Functional Residual Capacity ◽  
Vital Capacity ◽  
Cross Sectional Area ◽  
X Rays ◽  
Sectional Area ◽  
Cross Sectional ◽  
Lung Capacity ◽  
Residual Capacity ◽  
Lateral Chest ◽  
Diaphragm Motion

To examine the effect of hyperinflation on the volume displaced by diaphragm motion (ΔVdi), we compared nine subjects with emphysema and severe hyperinflation [residual volume (RV)/total lung capacity (TLC) 0.65 ± 0.08; mean ± SD] with 10 healthy controls. Posteroanterior and lateral chest X rays at RV, functional residual capacity, one-half inspiratory capacity, and TLC were used to measure the length of diaphragm apposed to ribcage (Lap), cross-sectional area of the pulmonary ribcage, ΔVdi, and volume beneath the lung-apposed dome of the diaphragm. Emphysema subjects, relative to controls, had increased Lap at comparable lung volumes (4.3 vs. 1.0 cm near predicted TLC, 95% confidence interval 3.4–5.2 vs. 0–2.1), pulmonary rib cage cross-sectional area (emphysema/controls 1.22 ± 0.03, P < 0.001 at functional residual capacity), and ΔVdi/ΔLap (0.25 vs. 0.14 liters/cm, P < 0.05). During a vital capacity inspiration, relative to controls, ΔVdi was normal in five (1.94 ± 0.51 liters) and decreased in four (0.51 ± 0.40 liters) emphysema subjects, and volume beneath the dome did not increase in emphysema (0 ± 0.36 vs. 0.82 ± 0.80 liters, P < 0.05). We conclude that ΔVdi can be normal in emphysema because 1) hyperinflation is shared between ribcage and diaphragm, preserving Lap, and 2) the diaphragm remains flat during inspiration.

Sex differences in growth patterns of the airways and lung parenchyma in children

1984 ◽  
Vol 56 (5) ◽  
pp. 1204-1210 ◽  
Author(s):  
R. D. Pagtakhan ◽  
J. C. Bjelland ◽  
L. I. Landau ◽  
G. Loughlin ◽  
W. Kaltenborn ◽  
...  
Keyword(s):  
Sex Differences ◽  
Vital Capacity ◽  
Total Lung Capacity ◽  
Somatic Growth ◽  
Lung Parenchyma ◽  
Growth Patterns ◽  
Sectional Area ◽  
Cross Sectional ◽  
Lung Capacity ◽  
Rates Of Growth

Seventeen boys and 19 girls, 8–15 yr in age, were studied to ascertain, in the two sex groups, the predictors of airway size [assessed by measurement of tracheal cross-sectional area (CSA) and maximal expiratory flows (Vmax)] and the relative rates of growth of the major divisions of the airways and lung parenchyma. In boys, total lung capacity (TLC) accounted for 77% of the variance of CSA and for 66% of the variability of Vmax. In contrast, somatic growth and maturation in girls accounted for only 45% of the variance of CSA and for 64% of the variability of Vmax; TLC was relatively unimportant. In boys, but not in girls, TLC-corrected CSA was significantly and inversely related to height and to TLC. In girls, TLC-corrected Vmax at 50 and 75% of forced vital capacity were directly related to height. These observations suggest different patterns of airway-parenchymal-somatic growth relationships in the two sexes. Furthermore, parenchymal growth appears to be the best determinant of airway growth in boys. In girls, other factors, perhaps genetic in nature, besides growth of parenchyma, may help determine airway size.

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

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