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In the past, since the reperfusion part is less than 10% of the total vascular system composed of multiple inputs, such as lungs, the γ-variate function was used as a method of eliminating the reperfusion component. In this research, an analytical method that separates and evaluates all blood flow systems by modeling the impulse response of the blood flow system with multiple inputs was proposed. In addition, a calibration method to adjust the input/output waveform areas was also proposed. The proposed method was verified in a patient with lung cancer. The lung total blood volume using the contrast MR image and the global lung blood volume estimated from the pulmonary artery and the signal strength of the left atrium were also compared. Moreover, the lung field reperfusion percentage was compared with the cardiac output detected by Fast GE Cine.

The marching cubes (MC) algorithm is employed to generated triangular meshes for visualizing medical images, sculpture scans and mathematical surfaces. It sequentially traverses cuberille data composed of sampled points of a scalar volumetric data. This paper proposes a propagation-based MC algorithm that uses the open boundary loop concept. The open boundary loop is used to determine adjacent cells for the next iteration of the MC algorithm. After inserting each triangle, the open boundary loop is reevaluated. Simultaneously, it is ensured that all triangles are coherently oriented and there are no holes on the isosurface. Several tests are conducted to determine the performance of the algorithm in comparison with the original MC algorithm. Results from these tests indicate that, for large-scale problems, the proposed algorithm performs better than the original.

A 3D reconstruction method using feature points is presented and the parameters used to improve the reconstruction are discussed. The precision of the 3D reconstruction is improved by combining point clouds obtained from different viewpoints using structured light. A well-known algorithm for point cloud registration is the ICP (Iterative Closest Point) that determines the rotation and translation that, when applied to one of the point clouds, places both point clouds optimally. The ICP algorithm iteratively executes two main steps: point correspondence determination and registration algorithm. The point correspondence determination is a module that, if not properly executed, can make the ICP converge to a local minimum. To overcome this drawback, two techniques were used. A meaningful set of 3D points using a technique known as SIFT (Scale-invariant feature transform) was obtained and an ICP that uses statistics to generate a dynamic distance and color threshold to the distance allowed between closest points was implemented. The reconstruction precision improvement was implemented using meaningful point clouds and the ICP to increase the number of points in the 3D space. The surface reconstruction is performed using marching cubes and filters to remove the noise and to smooth the surface. The factors that influence the 3D reconstruction precision are here discussed and analyzed. A detailed discussion of the number of frames used by the ICP and the ICP parameters is presented.

Image registration is an efficient computational technique for diagnosis and diseases monitoring. Lungs airways diseases, such as chronic obstructive pulmonary disease (COPD) and asthma, require periodical checkups and past data comparison to estimate the patient condition. In this work, it is proposed an airways registration algorithm that is performed branch by branch. The branch registration combines the positive aspects from the conventional ICP and skeleton registration algorithms. The registration procedure requires two main modules: point correspondence determination, and transformation determination. The point correspondence determination is the most time consuming and it is performed in high speed using a 3D discrete Voronoi diagram. Copyright ©2015 IF AC.

The diaphragm is an important component of the respiratory pumping process. Orthogonal temporal sequences of MR images are acquired in free breathing without use of contrast. The vertical intersection between two orthogonal temporal sequences is determined, the diaphragmatic level in the vertical segment is determined and used to perform the temporal registration. Previous works used similar temporal registration algorithms to reconstruct the diaphragmatic surface. However, it is shown that the available information was not efficiently used. The proposed method massively performs temporal registrations, and then validates the determined temporal registrations. The images to be used in the diaphragmatic surface reconstruction are determined and its associated diaphragmatic levels are collected. Positions with inconsistencies have their diaphragmatic level determined by interpolation. The proposed algorithm is tested with MR image sequences obtained from a healthy subject.

In order to remain in a monotonic concentration-signal relationship, tracer with low concentration is usually administrated. A new tracer concentration quantification to determine the non-monotonic effect and to enable the correct interpretation of the MR signal intensity, is proposed. It is based on the evaluation of the MR signal intensity in time that might have multiple peaks. A new method for perfusion analysis is also proposed, that is based on the blood flow inside the vessels like the γ variate model and the extravasation as the two compartment model. Samples of processing results of the proposed method applied to patients with confirmed cancer and pulmonary embolus are presented.

The objective of this work is to use low precision laser sensor and create reasonably precise 3D reconstructions. The 3D reconstruction is executed by combining several point clouds obtained from different viewpoints. The proposed method was developed with three main steps: point cloud registration, error compensation and surface reconstruction. The ICP algorithm is improved to execute the point cloud registration: dynamic distance threshold, weighted distance, rigid body restriction and color information. It is shown that using this improved ICP, the number of point correspondences to evaluate the quadratic error converges to a value. The quadratic error can be determined independently of scene complexity. The point cloud errors are compensated using the consensus surface algorithm with signed distance. The surface is reconstructed using the marching cubes algorithm. Several results are shown to demonstrate the reliability of the proposed method.

The use of chromatographic impulse response (CIR) method with a coated open tubular capillary column has potential advantages in supercritical fluid chromatography. In this review, applications of the CIR method to measuring the thermodynamic properties such as diffusion coefficients, solubilities and partial molar volumes are presented. This survey gives the theoretical backgrounds for the CIR method with linear adsorption and nonlinear adsorption models. Furthermore, the brief theoretical backgrounds for using retention factors to determine solubilities and partial molar volumes are also provided. In addition, the data sources for the diffusion coefficients with an emphasis on the results published after 2004 and for the partial molar volumes in supercritical carbon dioxide are presented.

This work proposes a novel functionality for computerized tomography (CT) based investigation of diffuse lung diseases diagnosis that enables the evaluation of the disease with lung anatomical structures. Automated methods for segmenting several anatomy structures in chest CT are proposed: namely the lungs, airway trees and pulmonary vessels trees. The airway and pulmonary vessels trees are segmented using a failure and recovery algorithm. The algorithm checks intermediary results consistence, backtrack to a history position if a failure is detected. The quality of the result is improved while reducing the processing time even for subjects with lung diseases. The pulmonary vessels are segmented through the same algorithm with different seed points. The seed for the airway segmentation is within the tracheal tube, and the seed for the pulmonary vessels segmentation is within the heart. The algorithm is tested with CT images acquired from three distinct types of subjects: healthy, idiopathic interstitial pneumonias (IIPs) and chronic obstructive pulmonary disease (COPD). The main bronchus are found in the segmented airways and the associated lung lobes are determined. Combining the segmented lung lobes and the diffuse lung diseases classification, it is possible to quantify how much and where of each lobe is injured. The proposed algorithm was evaluated to be robust enough to segment the studied cases.

The solubilities of organometallic complexes in supercritical CO 2 were determined from retention factors measured by the chromatographic impulse response (CIR) method, in which a solute was pulse-injected into a supercritical CO 2 flowing in a polymer coated open capillary column, and the response curve, i.e. time change of solute concentration, was monitored at the exit of the column. The retention factor and binary diffusion coefficient were simultaneously obtained as two parameters so that the fitting error between response curves of solute species measured and calculated was minimized. The validities of the method and the apparatus employed in this study were verified by determining the solubilities of naphthalene, which have extensively been reported in the literature. Then, the solubilities of organometallic complexes such as ferrocene and cobalt (III) acetylacetonate in supercritical CO 2 were determined. The data determined in this study were in good agreement with the literature data. The solubilities were also correlated with the Chrastil equation including the three adjustable parameters.

We propose a new method for evaluating the lung field motion complexity in magnetic resonance (MR) image temporal sequences, where complexity is defined as the minimum number of respiratory movement patterns to represent the detected lung field motion. In the first part of this work, a method for high precision landmark determination and tracking on a temporal sequences of chest magnetic resonance images is proposed. The landmark determination and tracking algorithms are based on a hierarchical template matching algorithm. A stable matching is made with some additional rules to avoid mistracking. In the second part of this work, the optimum respiratory movement patterns are determined by minimizing the mean square error applied to the determined paths. The proposed algorithm was tested with 29 subjects, including healthy subjects and COPD (Chronic Obstructive Pulmonary Disease) patients. The paths obtained by the landmark tracking algorithm represent the movement of some parenchyma internal structures. The paths automatically obtained were analyzed and compared to paths manually obtained by a medical specialist. It is concluded that the respiratory movement patterns necessary to represent the paths determined manually and automatically for the same subjects were compatible. The results also show that COPD patients have two main respiratory movement patterns. Copyright © 2011 IFAC.

This work discusses the determination of the breathing patterns in time sequence of images obtained from magnetic resonance (MR) and their use in the temporal registration of coronal and sagittal images. The registration is made without the use of any triggering information and any special gas to enhance the contrast. The temporal sequences of images are acquired in free breathing. The real movement of the lung has never been seen directly, as it is totally dependent on its surrounding muscles and collapses without them. The visualization of the lung in motion is an actual topic of research in medicine. The lung movement is not periodic and it is susceptible to variations in the degree of respiration. Compared to computerized tomography (CT), MR imaging involves longer acquisition times and it is preferable because it does not involve radiation. As coronal and sagittal sequences of images are orthogonal to each other, their intersection corresponds to a segment in the three-dimensional space. The registration is based on the analysis of this intersection segment. A time sequence of this intersection segment can be stacked, defining a two-dimension spatio-temporal (2DST) image. The algorithm proposed in this work can detect asynchronous movements of the internal lung structures and lung surrounding organs. It is assumed that the diaphragmatic movement is the principal movement and all the lung structures move almost synchronously. The synchronization is performed through a pattern named respiratory function. This pattern is obtained by processing a 2DST image. An interval Hough transform algorithm searches for synchronized movements with the respiratory function. A greedy active contour algorithm adjusts small discrepancies originated by asynchronous movements in the respiratory patterns. The output is a set of respiratory patterns. Finally, the composition of coronal and sagittal image pairs that are in the same breathing phase is realized by comparing of respiratory patterns originated from diaphragmatic and upper boundary surfaces. When available, the respiratory patterns associated to lung internal structures are also used. The results of the proposed method are compared with the pixel-by-pixel comparison method. The proposed method increases the number of registered pairs representing composed images and allows an easy check of the breathing phase.

Infinite dilution binary diffusion coefficients, D12, of ferrocene, 1,1′-dimethylferrocene and ethylferrocene in hexane, cyclohexane and ethanol at 313.2 K and pressures from 0.2 to 19 MPa, in acetonitrile at 298.2–333.2 K and 0.2 MPa, and various metallic acetylacetonate, acac, complexes such as Co(acac)3, Ru(acac)3, Rh(acac)3, Pd(acac)2 and Pt(acac)2 mainly in ethanol at 313.2 K and 0.2 MPa were measured by the Taylor dispersion method. The D12 values in m2 s−1 for the three ferrocenes in the present study and those of ferrocene and 1,1′-dimethylferrocene in supercritical carbon dioxide in our previous studies were represented by the modified hydrodynamic equation over a wide range of viscosity: M0.5D12/T = 1.435 × 10−13η−0.8446 with average absolute relative deviation of 2.40% for 316 data points, where M is the solute molecular weight, T is the temperature in K, η is the solvent viscosity in Pa s. Although the D12 values for the acac complexes were roughly represented by the above hydrodynamic equation, the accuracies were lower because they were dependent on not solute molecular weight but the number of acac ligand in the complex molecules.

Binary diffusion coefficients, D12, of the metal acetylacetonates, palladium(II) acetylacetonate and cobalt(III) acetylacetonate, were measured from 308.2 to 343.2 K over the pressure range from 9 to 40 MPa at infinite dilution in supercritical carbon dioxide using the chromatographic impulse response method. The effects of pressure, temperature, density, and viscosity on D12 values were examined. It was observed that the D12 values of palladium(II) acetylacetonate and cobalt(III) acetylacetonate were larger than those of lipids with similar molecular weights, such as arachidonic acid and monoolein, respectively. Furthermore, the measured D12 data of each metal acetylacetonate were well correlated by the hydrodynamic equation D12/T as a function of carbon dioxide viscosity.

Binary diffusion coefficients D12 and retention factors k of ferrocene and 1,1′-dimethylferrocene at infinite dilution in supercritical (sc) carbon dioxide were measured by the chromatographic impulse response (CIR) method at temperatures from (308.2 to 323.2) K over a pressure range from (8.0 to 40.3) MPa for ferrocene and from (8.2 to 40.1) MPa for 1,1′-dimethylferrocene. The D12 data for ferrocene were also measured by the Taylor dispersion method with two injection procedures of ferrocene: ferrocene dissolved both in sc CO2 and in liquid hexane. The D12 values of ferrocene were not affected by the injection methods and agreed with those measured by the CIR method. As has been seen for various organic compounds measured in our previous reports, the D12 data for both metal complexes were correlated with the hydrodynamic equation D12/T = αηβ, where η is the CO2 viscosity and α and β are the constants determined by each solute. The retention factors were also correlated with CO2 density.

This work discusses a 4D lung reconstruction method from unsynchronized MR sequential images. The lung, differently from the heart, does not have its own muscles, turning impossible to see its real movements. The visualization of the lung in motion is an actual topic of research in medicine. CT (Computerized Tomography) can obtain spatio-temporal images of the heart by synchronizing with electrocardiographic waves. The FOV of the heart is small when compared to the lung's FOV. The lung's movement is not periodic and is susceptible to variations in the degree of respiration. Compared to CT, MR (Magnetic Resonance) imaging involves longer acquisition times and it is not possible to obtain instantaneous 3D images of the lung. For each slice, only one temporal sequence of 2D images can be obtained. However, methods using MR are preferable because they do not involve radiation. In this paper, based on unsynchronized MR images of the lung an animated B-Rep solid model of the lung is created. The 3D animation represents the lung's motion associated to one selected sequence of MR images. The proposed method can be divided in two parts. First, the lung's silhouettes moving in time are extracted by detecting the presence of a respiratory pattern on 2D spatio-temporal MR images. This approach enables us to determine the lung's silhouette for every frame, even on frames with obscure edges. The sequence of extracted lung's silhouettes are unsynchronized sagittal and coronal silhouettes. Using our algorithm it is possible to reconstruct a 3D lung starting from a silhouette of any type (coronal or sagittal) selected from any instant in time. A wire-frame model of the lung is created by composing coronal and sagittal planar silhouettes representing cross-sections. The silhouette composition is severely underconstrained. Many wire-frame models can be created from the observed sequences of silhouettes in time. Finally, a B-Rep solid model is created using a meshing algorithm. Using the B-Rep solid model the volume in time for the right and left lungs were calculated. It was possible to recognize several characteristics of the 3D real right and left lungs in the shaded model.

The hydrodynamic equation D / T = αη β , where D is the infinite dilution binary diffusion or self-diffusion coefficient, T is the temperature, η is the fluid viscosity, and α and β are constants, were demonstrated to be effective for predicting both binary diffusion and self-diffusion coefficients in high density fluids, i.e. liquid and supercritical states. When a solute was specified, the correlation well represented both binary diffusion and self-diffusion coefficients, irrespective of solvent over a wide solvent viscosity range. The solute-dependent constants α and β were determined for 12 solutes with average absolute deviation of 6.2% for 1006 data points.

Two kinds of tracer response measurements, by the Taylor dispersion method using a stainless-steel diffusion column and the chromatographic impulse response (CIR) method using a polymer-coated diffusion column, were carried out by using the curve fitting to determine infinite-dilution binary diffusion coefficients of vitamin K3 (2-methylnaphthalene-1,4-dione), as a medium polar compound, in supercritical CO2 at 308.2 K and pressures from 7.75 to 31.00 MPa. The response curves in the Taylor dispersion method showed more significantly tailing closer to the critical point, whereas those did not at conditions away from the critical point. However, the CIR method provided the response curves almost without tailing over an entire range of pressure studied. Consequently, in the CIR method the response curves were accurately reproduced with the determined values of two parameters, binary diffusion coefficient and retention factor. The determined values of diffusion coefficients showed a little slow-down in the near critical region. In the Taylor dispersion method, however, the response curves with tailing were poorly reproduced with the determined values of diffusion coefficients, which apparently led to a steep-down in the near critical region.

Binary diffusion coefficients D12 and retention factors k for dibenzo-24-crown-8 and 15-crown-5 ethers at 308.18 and 313.20 K, and vitamin K1 at 313.20 K were measured in supercritical carbon dioxide by the chromatographic impulse response technique, and the effects of molecular shapes on the D12 values were studied. At 313.2 K and 11.0 MPa the D12 value of 15-crown-5 was higher than that predicted from the D12 correlation with molecular weight MW over the range from 32 of methanol to 1138 of trinervonin reported in our previous studies, while the D12 value of dibenzo-24-crown-8, disk shape molecule with MW = 448.5, was almost in agreement with that of vitamin K1, long chain molecule with MW = 450.7, and with those predicted from the correlation.

Purpose To evaluate the effect of ventilatory impairment on MR signal intensity of the lung parenchyma. Materials and Methods Subjects were five normal volunteers (age = 30 ± 7.9 years, mean ± SD) and 19 male patients with chronic obstructive lung disease (COPD) (mean age = 70.4 ± 6.5 years). Coronal MR images were obtained over entire lung fields at full inspiration and full expiration with cardiac triggering on a 1.5T system. Changes in the mean lung intensity between the two respiratory states were normalized by each intercept of the linear regression lines of the signal changes, and the slope of the relationship was calculated. Computed tomography (CT) images were also obtained in COPD patients at full inspiration using a multidetector row CT scanner. Attenuation values less than −950 Hounsfield units (HU) (RA-950) represented the percentage of relative lung area on the CT. Results The mean slope of COPD patients (0.365 ± 0.074) was less steep than that of the normal subjects (0.570 ± 0.124, P < 0.001). In COPD patients, the slope correlated significantly with forced expiratory volume in one second (FEV1, r = 0.508, P = 0.026), but not with RA-950. Conclusion In COPD patients, lung signal change measured by MRI correlates with airflow obstruction, but not with volume of the emphysema measured by lung CT. J. Magn. Reson. Imaging 2007. © 2007 Wiley-Liss, Inc.

Dr. Aydin Akgerman greatly contributed to studies on diffusion in liquids and supercritical fluids, in particular, measurements by the Taylor dispersion method. Based on his work, this article describes recent progress in measurements for binary diffusion coefficients in supercritical fluids by using the chromatographic impulse response technique as well as the Taylor dispersion method, and in the predictive empirical correlations. The data reported in the literature and the proposed correlations are also briefly reviewed together with the research subjects to be investigated in future.

The chromatographic impulse response (CIR) method with curve fitting was employed for measuring binary diffusion coefficients D12 at infinite dilution for polar compounds such as benzoic acid and C1 to C3 mono-alcohols in supercritical (SC) carbon dioxide at 313.2 K and pressures higher than 9.5 MPa. The measured D12 values for the polar compounds were expressed with two correlations which well represent binary diffusion coefficients for non-polar and weak polar compounds, i.e. the correlation of D12/T as a function of CO2 viscosity and the Schmidt number correlation. Moreover, the slope was −0.5 in logarithmic plot of D12 versus solute molecular weight over the range of molecular weight from 32 to 1138 at 313.2 K and 11.0 MPa.

Infinite dilution binary diffusion coefficients D12 and retention factors k for γ-linolenic acid were measured by chromatographic impulse response technique in supercritical carbon dioxide over the ranges of temperature from 308 to 343 K and pressure from 9 to 30 MPa, together with those for the methyl and ethyl esters at 313 and 343 K and pressures from 8 to 16 MPa. In comparison with literature values for C18 free fatty acids and the esters, the differences in D12 data were almost indiscernible for each isomer group: α- and γ-linolenic acid, oleic and elaidic acids, oleic and elaidic acid methyl esters, and their ethyl esters. The number of carbon double bonds did not affect the D12 values significantly. Moreover, the differences in the values between free fatty acid and the ester forms were also small, whereas the D12 values increased in order of acid to ethyl ester to methyl ester. The validities of the predictive correlations we had proposed such as the D12/T–CO2 viscosity and the Schmidt number correlation were verified. The retention factor k values for the acid form were much higher than those for the methyl and ethyl esters. The k values were correlated with temperature and CO2 density for each compound, and the solute partial molar volumes were determined from the k–CO2 density correlation.

Infinite dilution binary diffusion coefficients D12 and retention factors k have been measured in supercritical carbon dioxide for the long-chain triglyceride triarachidonin at 313.2 K at (10 to 30...

To determine binary diffusion coefficients from tracer response measurements with a coiled capillary column (curved tube) at relatively high flow rates, a conversion formula to correct for the secondary flow effect was derived from the second central moment of the impulse response curve. Its practical expression was obtained analytically by the perturbation method up to λ10, where λ is the ratio of the tube radius to the coil radius. The reliability of the correction was evaluated by an alternative series of λ. As a result, the effective range of DeSc1/2

A noise elimination technique was applied to the determination of binary diffusion coefficients D 12 from the response curves having extremely low absorbance intensities in impulse response methods under supercritical conditions of carbon dioxide. The effectiveness of this technique was experimentally examined for the analyses of response curves through both the curve-fitting and the moment methods in two cases: the chromatographic impulse response method for phenol and β-carotene with a polymer-coated capillary column, and the Taylor dispersion method for acetone with an uncoated capillary column. Unreliable D 12 values were obtained from the moment method of the response curves at lower absorbance intensities, even treated with noise elimination. The curve-fitting method with the noise elimination treatment was quite effective for determining the D 12 values accurately, and was valid at the lowest absorbance intensities, on the order of 10 −4 absorbance unit of UV-Vis multi-detector, corresponding to the smallest quantity of the solute, i.e. 6×10 −5 , 6×10 −6 , and 5×10 −2 μ mol for phenol, β-carotene, and acetone, respectively, under conditions studied. Infinite dilution regions for binary diffusion coefficients were obtained by injecting various amounts: the binary diffusion coefficients showed constant values at concentrations less than 0.6, 0.004, and 0.08 mol m −3 for phenol, β-carotene, and acetone, respectively, in supercritical carbon dioxide at 313.2 K and 16–18 MPa.

This review describes impulse response techniques with a curve-fitting method to measure thermodynamic properties, such as binary diffusion coefficient, retention factor, and partial molar volume, under supercritical conditions. Theoretical background, parameter sensitivity, sources of experimental error, noise elimination technique, and the correction of apparent binary diffusion coefficients due to column coiling are discussed based on recent studies, together with data sources and predictive correlations for binary diffusion coefficients.

Infinite dilution binary diffusion coefficients and retention factors for the oleic acid family such as oleic acid, methyl- and ethyl esters, and mono-, di-, and triglycerides at 313.21 K and 8–30 MPa, and for other 13 lipids consisting of C18–C22 unsaturated fatty acid constituents at 313.21 K and 11 MPa were measured in carbon dioxide by a chromatographic impulse response method with a polymer coated capillary column. The binary diffusion coefficients and the retention factors for each compound decreased with increasing pressure. The binary diffusion coefficients could be represented by a Schmidt number correlation and by an empirical equation written in terms of temperature and CO 2 viscosity. The retention factors for each solute could be expressed in terms of CO 2 density. While the binary diffusion coefficients at 313.21 K and 11 MPa decreased with solute molecular weight, those for compounds having the same carbon numbers in each group, such as methyl ester, ethyl ester, and triglyceride, decreased with increasing the number of C–C double bonds.

The chromatographic impulse response technique with the curve fitting method is a useful tool to measure binary diffusion coefficient under supercritical conditions. Based on our recent measurement data, the effectiveness of the simple predictive correlations such as the D12-viscosity correlation and the Schmidt number correlation is presented. Moreover, the sensitivities of the parameters determined and sources of experimental error are discussed.

We have developed a system to classify cellular forms of fusion proteins with an enhanced yellow fluorescent protein (EYFP) into subcellular compartments using images by a fluorescent microscope. The system aims at image classification to accommodate the multiplicity of cellular forms. The cellular forms automatically searched for in the images are classified with excellent reliability using statistical pattern recognition. The patterns are extended models of the cellular forms which are the result of protein localization as seen in seven standard subcellular compartments, including in the apoptosis and the overexpression. The image itself is classified by the majority of cellular forms it contains so as to reflect the characteristics of cell population, rejecting cellular forms with low reliability and in the apoptosis. We have found that our system is 97.9% accurate in classifying cellular forms into subcellular compartments.

The sequence of the human genome has been determined. The next task is to determine the function of the genes. Classifying cellular forms of proteins encoded by human cDNA clones is a primary step toward understanding the biological role of proteins and their coding genes. We report here our ongoing work on an automatic system to facilitate this classification. Our system handles the transfection, incubation, acquisition of microscopic images of the cells, and the classification of forms there appearing in the images. Our system correctly classified proteins by their forms at a rate of 90% in feasibility studies. To cite this article: R. Minamikawa-Tachino et al., C. R. Biologies 326 (2003).

Binary diffusion coefficients D12 and partition ratios k at infinite dilution for β-carotene and α-tocopherol in supercritical carbon dioxide were measured at temperatures from 308.15 to 333.15 K and pressures from 9 to 30 MPa by a tracer response technique with a poly(ethylene glycol) coated capillary column. Both parameters, simultaneously determined by fitting the calculated response curve to that measured experimentally, were well represented with the correlations: the D12/T values were correlated with CO2 viscosity, and the k values were expressed with a function of temperature and CO2 density. However, the partial molar volumes obtained from the k values were not well consistent with those estimated using equation of states having the interaction parameters kij reported in the literature.

A tracer response technique with a poly(ethylene glycol) coated capillary column was employed to measure binary diffusion coefficient and partition ratio for the ω3 group of long chain unsaturated fatty acids such as docosahexaenoic acid, eicosapentaenoic acid and α-linolenic acid at infinite dilution in supercritical (SC) carbon dioxide at temperatures from 308.15 to 343.15 K and pressures from 9 to 30 MPa. The binary diffusion coefficients for each solute were expressed with the Schmidt number correlation as well as the correlation with temperature and CO2 viscosity. The partition ratios were correlated with temperature and CO2 density. Moreover, the partial molar volumes were obtained from the partition ratios for each solute.

The binary diffusion coefficient D12 and partition ratio k were measured for two ω6 group compounds, linoleic acid and arachidonic acid, at infinite dilution in carbon dioxide at temperatures from 308.15 K to 343.15 K and pressures from 9 MPa to 30 MPa by a tracer response technique with a poly(ethylene glycol)-coated capillary column. The measured D12 values were well represented by a correlation of D12/T versus CO2 viscosity and by the Schmidt number correlation for each solute, and the k values were well represented as a function of temperature and CO2 density. Partial molar volumes were also obtained from the k values.

Infinite-dilution binary diffusion coefficient D12 and partition ratio k for ubiquinone CoQ10 in carbon dioxide were measured by a tracer response technique with a poly(ethylene glycol)-coated capillary column at temperatures from 308.15 to 333.15 K and pressures from 8.5 to 30 MPa. D12 and k values were simultaneously determined from a measured response curve by the curve-fitting method. The fitting error between measured and calculated response curves increased with decreasing pressure, as had been the case in our previous studies on various solutes in supercritical CO2 by the Taylor dispersion method. The D12 values were correlated with temperature and CO2 viscosity and the k values with temperature and CO2 density. Moreover, partial molar volumes of CoQ10 in supercritical CO2 were obtained from the k values.

Binary diffusion coefficients ( D 12 ) for low volatile compounds such as Vitamin K 3 , ubiquinone (UQ-10), α-tocopherol, β-carotene, and phenol in supercritical carbon dioxide were measured by the Taylor dispersion method with two columns connected in series: a poly(ethylene glycol) (PEG) coated capillary column followed by a stainless steel uncoated capillary column, at 313.15 K and pressures from 9 to 30 MPa. The tracer species dissolved with a common organic solvent such as hexane or chloroform was injected to the diffusion column as a delta shot through an ordinary HPLC injector. The response curve measured at the exit of the first column, coated with PEG, was regarded as an input signal, and that measured at the exit of the second column made of the uncoated stainless steel tubing as the output signal. The tracer species and the organic solvent were separated during flowing in the first column. The output response signal was calculated from the input signal and the inverse Laplace transform of the transfer function through the convolution integral. The D 12 values were determined by fitting the calculated output curve to that measured experimentally. The measured D 12 values were fully consistent with those measured with the PEG coated capillary column for one point measurement reported [Ind. Eng. Chem. Res. 39 (2000) 4462]. This two-point measurements with the two columns were adequate for measuring D 12 values for low volatile compounds in supercritical fluids.

The purpose of this study was to quantitatively evaluate paradoxical diaphragmatic motion using magnetic resonance (MR) imaging. A total of 27 subjects were examined, including 12 normal young adults, six control individuals, and nine patients with emphysema. With subjects in the supine position, 30 sequential sagittal MR images of the entire right lung were obtained during tidal and deep slow breathing. Diaphragmatic movement between sequential images was estimated as the displacement area and the total diaphragmatic movement in a respiratory cycle was calculated. The paradoxical motion of the diaphragm, representing the inverted movement to increase or decrease lung area, since paradoxical movement ratio (Mpr=(total paradoxical diaphragmatic movement/total diaphragmatic movement)x100), was evaluated. In patients with emphysema, paradoxical diaphragmatic motion was observed on MR images during deep breathing. The mean Mpr in emphysematous patients during deep breathing was 10+/-4%, which was significantly higher than 0.5+/-0.2% in young adults (p

Several respiratory diseases, such as COPD and asthma, requires periodical checkups and past data comparison. While this kind of analysis is usually done by a medical expert, it depends greatly on the medical expertise and the image quality. Image registration, a technique which compares images volumes automatically using predefined computational algorithms, is a great tool to assist on diagnosis and disease surveillance. Most studies analyze the registration on 3D CT images slice-by-slice. However, by segmenting a 3D point clouds from the 3D CT volumes, it is possible to analyze the data in different and more accurate ways. This paper proposes a high speed algorithm improvement that calculates the rigid registration between two point clouds, adapting the Iterative Closest Point (ICP) algorithm to use 3D Voronoi diagrams for point correspondence determination, reducing the processing time greatly. A benchmark performance test is done with a point-by-point variation of the algorithm, showing that the proposed algorithm yield the same results with a considerable processing time reduction.

The objective of this work is to present an object 3D reconstruction method using the point color information. The object 3D reconstruction is performed by combining point clouds obtained from different viewpoints using two cameras and a structured light projector. The main task is the point cloud registration algorithm that matches two point clouds. A well known algorithm for point cloud registration is the ICP (Iterative Closest Point) that determines the rotation and translation that when applied to one of the point clouds, place both point clouds in accordance. The ICP algorithm executes iteratively two main steps: point correspondence determination and registration algorithm. The point correspondence determination is a module that if not executed properly can make the ICP to converge to a local minimum. To overcome such drawback an ICP that uses statistics to generate a dynamic distance and color threshold on the distance allowed between closest points is proposed and implemented. This approach allows subset matches, instead of matching all points from the point clouds. The surface reconstruction is performed using Marching Cubes and a consensus surface algorithm with signed distance compensates point cloud errors. In this paper the performance of the proposed method is analyzed and compared with the classical ICP.

In this work, segmentation is an intermediate step in the registration and 3D reconstruction of the lung. New MR imaging protocols have been used to enhance the lung internal structures and, consequently, the lung boundary is weakened. This fact turns the segmentation of lung MR images particularly difficult. The algorithm proposed herein uses morphological operators to segment sagittal and coronal lung MR images. The algorithm is tested with several sagittal and coronal temporal sequences of MR images. Using the resulting segmentation, lung masks are created to determine the region with high probability where the lung contour is. The masks were used in a temporal segmentation algorithm based on Hough transform to determine the lung boundary with higher precision. The results showed to be robust and consistent under the MR temporal image sets tested.

Infinite dilution binary diffusion coefficients, D12, of benzene in carbon dioxide were measured by the Taylor dispersion technique at temperatures from 308.15 to 328.15 K and pressures from 6 to 30 MPa. The diffusion coefficients were obtained by the method of fitting in the time domain from the response curves measured with a UV–vis multidetector by scanning from 220 to 280 nm at increments of 1 or 4 nm. The wavelength dependences on the binary diffusion coefficient and the uncertainty were examined. The detector linearity, in terms of the relationship between the absorbance intensity and the product of the peak area of the response curve and CO2 velocity, was found to fail at some characteristic absorption wavelengths such as 243, 248, 253, and 259 nm, even when the maximum absorbance intensities of the response curves were less than 0.5 and the fits were good. Although the D12 values obtained from the response curves measured at 253 nm were almost consistent with some literature data, the D12 values measured at wavelengths showing the detector linearity to be satisfactory, i.e., at 239 nm, were higher than those at 253 nm. The present D12 data at 239 nm were well represented by the Schmidt number correlation, except for those showing the anomalous decrease in a plot of D12 vs density in the density range from 250 to 500 kg·m−3.

Binary diffusion coefficients, D 12 , and partition ratios, k, for the poly(ethylene glycol) (PEG) layer to supercritical carbon dioxide for acetone and some solid solutes such as phenol, α-tocopherol, and β-carotene were measured with a PEG-coated capillary column by a tracer response technique. The D 12 values for acetone with the PEG-coated column were consistent with those measured by the Taylor dispersion method in which an uncoated capillary column was employed. The D 12 and k values for all of the solutes decrease simply with increasing pressure, and the D 12 values were represented by the Schmidt number correlation.

The authors evaluate paradoxical diaphragmatic motion using magnetic resonance (MR) imaging in patients with emphysema. The subjects were 12 healthy volunteers and 10 male patients with moderate to severe air flow obstruction. With subjects in the supine position, 30 sequential sagittal images of the bilateral lungs were obtained during quiet and forced breathing using a 1.5T MR unit with a body coil. The sequence was single shot fast spin echo (SSFSE) with half Fourier transformation. Subtraction images were made from the original images (by subtracting a given image from the preceding image), which visualized the chest wall motion as white or black bands on the edge of the lung fields. The authors evaluated both the original and subtraction images. MR imaging showed abnormal hemidiaphragmatic motion during forced breathing: the ventral portion of the hemidiaphragm moved downward while the dorsal part moved upward like a seesaw in 6 patients. MR images also revealed abnormal ribcage motion; the ventral ribcage moved anteriorly when the hemidiaphragm moved upward in 7 patients. No abnormal motion was observed in healthy volunteers. MR is a noninvasive and useful tool for evaluating the asynchronous respiratory motion in patients with emphysema.

Infinite-dilution binary diffusion coefficients of 2-propanone, 2-butanone, 2-pentanone, and 3-pentanone in carbon dioxide were measured by the Taylor dispersion method at temperatures from 308.15 to 328.15 K and pressures from 7.60 to 34.57 MPa. The D 12 values were obtained from the response curves by the method of fitting in the time domain. The accuracy in the fitting error was examined for each measurement. The measured D 12 data were found to be well correlated by the Schmidt number correlation, with AAD%=3.74% for all solutes.

Binary diffusion coefficients of acetone in carbon dioxide were measured by the Taylor dispersion method at 308.2 K and 7.9 to 40 MPa and at 313.2 K and 8.0 to 37 MPa. The D 12 values obtained from the response curves by the method of fitting in the time domain were more accurate than those obtained by the moment method. At pressures lower than about 8.3 MPa at 308.2 K or 9.1 MPa at 313.2 K, the accuracy in the D 12 values was found to decrease significantly with decreasing pressure by examining (peak area)×u a, cal, the values of S 10, the fitting error e, and u a, cal/u a, exp as a function of pressure. The D 12 values at pressures higher than 8.3 MPa at 308.2 K or 9.1 MPa at 313.2 K were well represented with the Schmidt number correlation. The D 12 data with larger fitting errors (e>0.01) showed larger deviations from the values predicted by this correlation.

Effective axial dispersion coefficients Dax in packed beds were measured by the chromatographic method at 313.2 K both for supercritical CO2 in the pressure range from 11 to 35 MPa and for organic solvents at atmospheric pressure. The Dax values were correlated with the Reynolds number, Schmidt number, binary diffusivity and bed void fraction. The correlation was consistent for all solvents, irrespective of pressure.

Lung perfusion analysis with sequential contrasted MRI is an important clinical tool. This work is part of larger research in which the objective of fusing lung perfusion analysis and lung anatomical structures. In this work, it is proposed a multimodality MR/CT lung fusion algorithm based on lung vessel determination that analyzes lung perfusion. 3D contrasted MR and 3D CT images are first normalized (slice thickness, resolution and pixel intensity), then lung features are determined and elastically registered. The registration algorithm was checked by mapping in both directions, from MR to CT and vice-versa. A MR perfusion analysis result is fused with a 3D CT segmented lung vessel tree.

This work addresses the reconstruction of an animated lung surface by using respiratory patterns determined in temporal sequences of images obtained from Magnetic Resonance (MR). The reconstruction is done without the use of any triggering information and any special gas to enhance the contrast and the images temporal sequences are acquired in free breathing. The real movement of the lung has never been seen directly, as it is totally dependent on its surrounding muscles and collapses without them. Comparing with Computerized Tomography (CT), MR imaging involves longer acquisition times but it is preferable because it does not involve ionizing radiation. The multiple registration is based on the analysis of the intersecting segments among multiple coronal and sagittal sequences, since they are orthogonal to each other. The concepts of 2D spatiotemporal (2DST) image, respiratory function, Hough transform, active countors and temporal registration are used. The multiple registration algorithm used here allows the determination of the lung surface, given a fixed sagittal (coronal) MR image, by initially applying the temporal registration multiple times, then performing a three dimensional intersection points matching and finally reconstructing the lung surface with the points obtained from the previous step. Applying this method to all images of a temporal sequence, an animated 3D lung model is obtained. Some results and conclusions are shown.