Дискретно-континуальные системы: подходы, модели, программно-модельные комплексы

<div><p>Background</p><p>Diaphragm weakness is the main reason for respiratory dysfunction in patients with Pompe disease, a progressive metabolic myopathy affecting respiratory and limb-girdle muscles. Since respiratory failure is the major cause of death among adult patients, early identification of respiratory muscle involvement is necessary to initiate treatment in time and possibly prevent irreversible damage. In this paper we investigate the suitability of dynamic MR imaging in combination with state-of-the-art image analysis methods to assess respiratory muscle weakness.</p><p>Methods</p><p>The proposed methodology relies on image registration and lung surface extraction to quantify lung kinematics during breathing. This allows for the extraction of geometry and motion features of the lung that characterize the independent contribution of the diaphragm and the thoracic muscles to the respiratory cycle.</p><p>Results</p><p>Results in 16 3D+t MRI scans (10 Pompe patients and 6 controls) of a slow expiratory maneuver show that kinematic analysis from dynamic 3D images reveals important additional information about diaphragm mechanics and respiratory muscle involvement when compared to conventional pulmonary function tests. Pompe patients with severely reduced pulmonary function showed severe diaphragm weakness presented by minimal motion of the diaphragm. In patients with moderately reduced pulmonary function, cranial displacement of posterior diaphragm parts was reduced and the diaphragm dome was oriented more horizontally at full inspiration compared to healthy controls.</p><p>Conclusion</p><p>Dynamic 3D MRI provides data for analyzing the contribution of both diaphragm and thoracic muscles independently. The proposed image analysis method has the potential to detect less severe diaphragm weakness and could thus be used to determine the optimal start of treatment in adult patients with Pompe disease in prospect of increased treatment response.</p></div

Sediment Hydraulical Studies on the Control of Sediments. XI : Application of Vortex Tube Sand Trap to Storage Dams

The hydraulic problems of vortex tube sand trap with a jet flow gate and with a double-opened slit inlet are examined for its application to a storage dam. The behaviour of spiral flow in a vortex flow tube, inlet velocity to slit, and the efficiency of a linear sand trap in a modelled dam reservoir are tested more than 300 times using vortex flow tube with double-cylinder slit inlet. The grading at sediment terrace in a modelled reservoir is also examined after flushing sand

Relative AZLI concentrations in central and small airways of 2 patients for 3 different scenarios.

<p>Simulations of AZLI deposition in 2 patients, representing 3 scenarios of varied airway surface liquid thickness (ASL) and aerosol diameter. Severity of CF lung disease was determined by the CF-CT score (% of total CF-CT score). Scenario a = thin ASL with smallest aerosol diameter; scenario b = median ASL with median aerosol diameter; scenario c = thick ASL with largest aerosol diameter. <u>Part 1a, 1b and 1c:</u> Patient 1, mild CF lung disease: bronchiectasis 0.0%, airway wall thickening 0.0% and air trapping 11.1%. Patient 1 received concentrations > 10xMIC₉₀ in the central and small airways independent of ASL thickness and aerosol diameter (Part 1a, 1b, 1c). <u>Part 2a, 2c and 2c</u>: Patient 2, more severe lung disease: bronchiectasis 12.5%, airway wall thickening 11.1% and air trapping 38.9%. Patient 2 received concentrations > 10xMIC₉₀ in the central and small airways in scenario a and b (Part 2a and 2b), but AZLI concentrations < 10xMIC₉₀ in the small airways in scenario c (right upper and middle lobes) (Part 2c).</p

Comparison of CF-CT subscores per lobe.

<p>Comparison of CF-CT subscores per lobe, presented as % of max CF-CT score. Data are presented as median (range), unless otherwise indicated. White bars represent bronchiectasis score, light grey bars represent airway wall thickening score and dark grey bars represent air trapping score. RUL = right upper lobe (n = 22), RML = right middle lobe (n = 22), RLL = right lower lobe (n = 40), LUL = left upper lobe (n = 39), LLL = left lower lobe (n = 39).</p

Percentage area of small airways with AZLI <10xMIC₉₀.

<p>Percentage area of small airways with AZLI concentrations <10xMIC₉₀. Data are presented as median (range) for the different scenarios. White bars represent the smallest aerosol diameter (2.9 μm), light grey bars represent the median aerosol diameter (3.18 μm) and dark grey bars represent the largest aerosol diameter (4.35 μm). ASL = airway surface liquid.</p

Differences between lobes in AZLI concentrations.

<p>Differences between lobes in AZLI concentrations for the scenario of thick airway surface liquid with largest aerosol diameter. Data are presented as median (range), unless otherwise indicated. Significant differences in AZLI concentrations were found between all lobes, except for one pairwise comparison (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118454#pone.0118454.s003" target="_blank">S1 Table</a>). RUL = right upper lobe, RML = right middle lobe. RLL = right lower lobe, LUL = left upper lobe, LLL = left lower lobe.</p

Coupled mouthpiece/upper/lower airway model.

<p>Coupled mouthpiece/upper/lower airway model subdivided in multiple regions. Airways are segmented up to the 5^th-9^th generation.</p

Influence of inhalation technique on AZLI concentrations.

<p>Influence of inhalation technique on AZLI concentrations presented as percentage area of small airways with AZLI <10xMIC₉₀. Low breathing profile: tidal volume of 6 ml/kg (228 ml) and respiration rate of 14 breaths/min. Average breathing profile: tidal volume of 10 ml/kg (380 ml) and respiration rate of 18 breaths/min. High breathing profile: tidal volume of 14 ml/kg (532 ml) and respiration rate of 22 breaths/min. Data are presented as median (range) for the different scenarios. Light grey bars represent the scenario of median ASL (5 μm) with largest aerosol diameter (4.35 μm). The darker grey bars represent the scenario of thick ASL (7 μm) with median aerosol diameter (3.18 μm) and the darkest grey bars represent the scenario of thick ASL (7 μm) with largest aerosol diameter (4.35 μm). The scenarios of thin ASL with all diameters, median ASL with smallest and median diameter and thick ASL with smallest diameter are not represented as all breathing profiles resulted in AZLI concentrations above 10xMIC₉₀. ASL = airway surface liquid.</p

Chest wall and diaphragm contribution to overall lung volume change.

<p>The bar plot shows the amount of volume displaced by the costal surface (upper bars) and diaphragm surface (lower bars) for all subjects. Patients (<i>P01</i>—<i>P10</i>) and controls (<i>C01</i>—<i>C06</i>) are sorted within their group in descending order with respect to supine FVC (% of predicted).</p

Mesh representation of 3D lung segmentation.

<p>A 3D mesh of the lungs is presented in the left image. The surface is colored to distinguish between the different surface segments. On the right, the same mesh is shown after unfolding the individual surface segments into a plane. The orientation labels indicate the viewing direction.</p