Chest wall and lung volume estimation by optical reflectance motion analysis

1996 ◽  
Vol 81 (6) ◽  
pp. 2680-2689 ◽  
Author(s):  
S. J. Cala ◽  
C. M. Kenyon ◽  
G. Ferrigno ◽  
P. Carnevali ◽  
A. Aliverti ◽  
...  
Keyword(s):  
Chest Wall ◽  
Motion Analysis ◽  
Lung Volume ◽  
Close Correlation ◽  
Volume Estimation ◽  
Three Dimensions ◽  
Regression Equations ◽  
Optical Reflectance ◽  
Dimensional Measurements ◽  
Point Data

Cala, S. J., C. M. Kenyon, G. Ferrigno, P. Carnevali, A. Aliverti, A. Pedotti, P. T. Macklem, and D. F. Rochester. Chest wall and lung volume estimation by optical reflectance motion analysis. J. Appl. Physiol. 81(6): 2680–2689, 1996.—Estimation of chest wall motion by surface measurements only allows one-dimensional measurements of the chest wall. We have assessed an optical reflectance system (OR), which tracks reflective markers in three dimensions (3-D) for respiratory use. We used 86 (6-mm-diameter) hemispherical reflective markers arranged circumferentially on the chest wall in seven rows between the sternal notch and the anterior superior iliac crest in two normal standing subjects. We calculated the volume of the entire chest wall and compared inspired and expired volumes with volumes obtained by spirometry. Marker positions were recorded by four TV cameras; two were 4 m in front of and two were 4 m behind the subject. The TV signals were sampled at 100 Hz and combined with grid calibration parameters on a personal computer to obtain the 3-D coordinates of the markers. Chest wall surfaces were reconstructed by triangulation through the point data, and chest wall volume was calculated. During tidal breathing and vital capacity maneuvers and during CO2-stimulated hyperpnea, there was a very close correlation of the lung volumes (Vl) estimated by spirometry [Vl(SP)] and OR [Vl(OR)]. Regression equations of Vl(OR) ( y) vs. Vl(SP) ( x,btps in liters) for the two subjects were given by y = 1.01 x − 0.01 ( r = 0.996) and y = 0.96 x + 0.03 ( r = 0.997), and by y = 1.04 x + 0.25 ( r = 0.97) and y = 0.98 x + 0.14 ( r = 0.95) for the two maneuvers, respectively. We conclude spirometric volumes can be estimated very accurately and directly from chest wall surface markers, and we speculate that OR may be usefully applied to calculations of chest wall shape, regional volumes, and motion analysis.

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.

The use of hydroxyproline analyses to predict the nutritional value of the protein in different animal tissues

1972 ◽  
Vol 27 (3) ◽  
pp. 475-481 ◽  
Author(s):  
Z. Dvořák
Keyword(s):  
Amino Acids ◽  
Nutritional Value ◽  
Amino Acid Content ◽  
Close Correlation ◽  
Regression Equations ◽  
Animal Tissues ◽  
Chemical Score ◽  
Limiting Amino Acids ◽  
Net Protein ◽  
Total Amino Acids

1. The amounts of available cystine and tyrosine in the protein of different animal tissues showed a close correlation with the level of hydroxyproline, and may be estimated from hydroxyproline values by regression equations.2. Estimates of ‘chemical score’ have been calculated from the content of hydroxyproline determined in a series of samples for which net protein utilization (NPU) for rats had also been determined. Chemical scores calculated as percentages of the total ‘essential+semiessential’ amino acid content of each material correlated closely with NPU, whereas scores calculated as percentages of total amino acids did not. ‘Methionine+cystine’ were calculated to be first limiting amino acids in every sample.

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.

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.

scholarly journals Retrospective accuracy analysis of MRI based lesion size measurement in neuroblastic tumors: which sequence should we choose?

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Sebastian Gassenmaier ◽  
Ilias Tsiflikas ◽  
Simon Maennlin ◽  
Cristian Urla ◽  
Steven W. Warmann ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Tumor Size ◽  
Three Dimensional ◽  
Lesion Size ◽  
Three Dimensions ◽  
Neuroblastic Tumor ◽  
Significant Difference ◽  
Dimensional Measurements ◽  
Neuroblastic Tumors ◽  
Mri Measurements

Abstract Background MR imaging of neuroblastic tumors is widely used for assessing the effect of chemotherapy on tumor size. However, there are some concerns that MRI might falsely estimate lesion diameters due to calcification and fibrosis. Therefore, the aim of our study was to compare neuroblastic tumor size based on MRI measurements to histopathology measurements of the resected specimens as standard of reference. Methods Inclusion criteria were diagnosis of a neuroblastic tumor, MR imaging within 100 days to surgery and gross total resection without fragmentation of the tumor between 2008 and 2019. Lesion diameters were measured by two radiologists according to RECIST 1.1 in axial plane in T2w turbo spin echo (TSE), diffusion-weighted imaging (DWI), and in T1w pre- and postcontrast sequences. Furthermore, the largest lesion size in three-dimensions was noted. The largest diameter of histopathology measurements of each specimen was used for comparison with MRI. Results Thirty-seven patients (mean age: 5 ± 4 years) with 38 lesions (neuroblastoma: n = 17; ganglioneuroblastoma: n = 11; ganglioneuroma: n = 10) were included in this retrospective study. There was excellent intra-class correlation coefficient between both readers for all sequences (> 0.9) Tumor dimensions of reader 1 based on axial MRI measurements were significantly smaller with the following median differences (cm): T1w precontrast − 1.4 (interquartile range (IQR): 1.8), T1w postcontrast − 1.0 (IQR: 1.9), T2w TSE: -1.0 (IQR: 1.6), and DWI -1.3 (IQR: 2.2) (p < 0.001 for all sequences). However, the evaluation revealed no significant differences between the three-dimensional measurements and histopathology measurements of the resected specimens regardless of the applied MRI sequence. Conclusions Axial MRI based lesion size measurements are significantly smaller than histopathological measurements. However, there was no significant difference between three-dimensional measurements and histopathology measurements of the resected specimens. T2w TSE and T1w postcontrast images provided the lowest deviation and might consequently be preferred for measurements.

Chest wall and trunk muscle activity during inspiratory loading

1992 ◽  
Vol 73 (6) ◽  
pp. 2373-2381 ◽  
Author(s):  
S. J. Cala ◽  
J. Edyvean ◽  
L. A. Engel
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Normal Subjects ◽  
Systematic Difference ◽  
Erector Spinae ◽  
Inspiratory Pressure ◽  
Emg Activity ◽  
Consistent Difference ◽  
Lung Volumes ◽  
Resistive Loading

We measured the electromyographic (EMG) activity in four chest wall and trunk (CWT) muscles, the erector spinae, latissimus dorsi, pectoralis major, and trapezius, together with the parasternal, in four normal subjects during graded inspiratory efforts against an occlusion in both upright and seated postures. We also measured CWT EMGs in six seated subjects during inspiratory resistive loading at high and low tidal volumes [1,280 +/- 80 (SE) and 920 +/- 60 ml, respectively]. With one exception, CWT EMG increased as a function of inspiratory pressure generated (Pmus) at all lung volumes in both postures, with no systematic difference in recruitment between CWT and parasternal muscles as a function of Pmus. At any given lung volume there was no consistent difference in CWT EMG at a given Pmus between the two postures (P > 0.09). However, at a given Pmus during both graded inspiratory efforts and inspiratory resistive loading, EMGs of all muscles increased with lung volume, with greater volume dependence in the upright posture (P < 0.02). The results suggest that during inspiratory efforts, CWT muscles contribute to the generation of inspiratory pressure. The CWT muscles may act as fixators opposing deflationary forces transmitted to the vertebral column by rib cage articulations, a function that may be less effective at high lung volumes if the direction of the muscular insertions is altered disadvantageously.

SU-E-J-104: Is It Necessary to Do 4D-CT for Chest Wall EBRT? A Motion Analysis

2011 ◽  
Vol 38 (6Part8) ◽  
pp. 3466-3466
Author(s):  
Y Xu ◽  
G Ingram ◽  
S Lam ◽  
L Chong
Keyword(s):  
Chest Wall ◽  
Motion Analysis ◽  
4D Ct
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