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At least 19 recordsLinked to original sources
PubMed1999

HL7 document patient record architecture: an XML document architecture based on a shared information model.

The HL7 SGML/XML Special Interest Group is developing the HL7 Document Patient Record Architecture. This draft proposal strives to create a common data architecture for the interoperability of healthcare documents. Key components are that it is under the umbrella of HL7 standards, it is specified in Extensible Markup Language, the semantics are drawn from the HL7 Reference Information Model, and the document specifications form an architecture that, in aggregate, define the semantics and structural constraints necessary for the exchange of clinical documents. The proposal is a work in progress and has not yet been submitted to HL7's formal balloting process.

Humans↗
PubMed1990

Myocardial fiber architecture in the human heart. Anatomical demonstration of modifications in the normal pattern of ventricular fiber architecture in a malformed adult specimen.

Ventricular myocardial fiber architecture has been considered an important factor in heart dynamics. Most anatomical studies however have focussed on the analysis of normal hearts. The present study compares ventricular myocardial fiber architecture patterns in dissections of 5 normal hearts and a malformed human heart with membranous ventricular septal defect, overriding right aorta, pulmonic stenosis, with absent pulmonary valve and hypertrophied right ventricle. Qualitative and quantitative changes in ventricular myocardial fiber architecture were noted in the malformed heart.

Adolescent↗
PubMed2000

[The craniofacial architectural factors predisposing to a skeletal Class II identified by Jean Delaire's architectural analysis].

The current state-of-the-art medical practice involves considering treatment both in terms of symptomatology and etiology. In the case of dento-facial deformities, treatment and prognosis must deal both with constitutional and functional anomalies. Most accurate diagnosis can be achieved using Jean Delaire's architectural cephalometric analysis. We illustrate the usefulness of this system using examples of class II skeletal malocclusions. Class II cranial malocclusion factors appear to be difficult to treat successfully. Maxillary and mandibular functional and constitutional anomalies are described. Functional deformities such as anterior rotation of the maxilla or posterior rotation of the mandibular ramus, can be successfully treated with early orthopedic care. Constitutional anomalies, such as excess length of the premaxilla or maxillary vertical excess, should frequently be treated in a combined orthodontic-surgical sequence as orthopedic care alone is ineffective. This explains the usefulness of Jean Delaire's architectural approach to obtain stable results in the treatment of maxillo-mandibular deformities.

Cephalometry↗
PubMed1990

[Buildings for mental patients: from the architecture of isolation to the architecture of integration].

Traditional psychiatric hospitals designed for several thousand patients are very far from contributing to rapid recovery of the patients. Current investigations have demonstrated that such hospitals should be replaced by small rehabilitation centers designed for a minor number of patients (several dozens). The architecture of new psychiatric hospitals should fully comply with the treatment purposes. Thus, the hospital should have little comfortable wards, a large number of rooms for recreation purposes as well as provide accommodation for meetings with relatives and friends. Psychiatric hospitals should represent small institutions of the familial type.

Facility Design and Construction↗
PubMed2001

Comparative architecture of transposase and integrase complexes.

Transposases and retroviral integrases promote the movement of DNA segments to new locations within and between genomes. These recombinases function as multimeric protein-DNA complexes. Recent success in solving the crystal structure of a Tn5 transposase--DNA complex provides the first detailed structural information about a member of the transposase/integrase superfamily in its active, DNA-bound state. Here, we summarize the reactions catalyzed by transposases and integrases and review the Tn5 transposase-DNA co-crystal structure. The insights gained from the Tn5 structure and other available structures are considered together with biochemical and genetic data to discuss features that are likely to prove common to the catalytic complexes used by members of this important protein family.

Binding Sites↗
PubMed1998

High-resolution magnetic resonance imaging: three-dimensional trabecular bone architecture and biomechanical properties.

The purpose of this study was to use high-resolution magnetic resonance (MR) imaging combined with image analysis to investigate the three-dimensional (3D) trabecular structure, anisotropy, and connectivity of human vertebral, femoral, and calcaneal specimens. The goal was to determine whether: (a) MR-derived measures depict known skeletal-site-specific differences in architecture and orientation of trabeculae; (b) 3D architectural parameters combined with bone mineral density (BMD) improve the prediction of the elastic modulus using a fabric tensor formulation; (c) MR-derived 3D architectural parameters combined with BMD improve the prediction of strength using a multiple regression model, and whether these results corresponded to the results obtained using higher resolution depictions of trabecular architecture. A total of 94 specimens (12 x 12 x 12 mm cubes) consisting of trabecular bone only were obtained, of which there were 7 from the calcaneus, 15 from distal femur, 47 from the proximal femur, and 25 from the vertebral bodies. MR images were obtained using a 1.5 Tesla MR scanner at a spatial resolution of 117 x 117 x 300 microm. Additionally, BMD was determined using quantitative computed tomography (QCT), and the specimens were nondestructively tested and the elastic modulus (YM) was measured along three orthogonal axes corresponding to the anatomic superior-inferior (axial), medial-lateral (sagittal), and anterior-posterior (coronal) directions. A subset of the specimens (n=67) was then destructively tested in the superior-inferior (axial) direction to measure the ultimate compressive strength. The MR images were segmented into bone and marrow phases and then analyzed in 3D. Ellipsoids were fitted to the mean intercept lengths, using single value decomposition and the primary orientation of the trabeculae and used to calculate the anisotropy of trabecular architecture. Stereological measures were derived using a previously developed model and measures such as mean trabecular width, spacing, and number were derived. Because the spatial resolution of MR images is comparable to trabecular bone dimensions, these measures may be subject to partial volume effects and were thus treated as apparent measures, such as BV/TV, Tb.Sp, Tb.N, and Tb.Th rather than absolute measures, as would be derived from histomorphometry. In addition, in a subset of specimens, the Euler number per unit volume was determined to characterize the connectivity of the trabecular network. There were significant differences in the BMD, trabecular architectural measures, elastic modulus, and strength at the different skeletal sites. The primary orientation axes for most of the specimens was the anatomic superior-inferior (axial) direction. Using the fabric tensor formulation, in addition to BMD, improved the prediction of YM (SI), while including some of the architectural parameters significantly improved the prediction of strength. In comparing MR-derived 3D measures with those obtained from 20 microm optical images (n=18; 9 vertebrae, 9 femur specimens), good correlations were found for the apparent Tb.Sp and Tb.N, moderate correlation was seen for the apparent BV/TV, and poor correlation was found for the apparent Tb.Th. Using these higher resolution images, the fabric tensor formulation for predicting the elastic modulus also showed improved correlation between the measured and calculated modulus in the axial (SI) direction. In summary, high-resolution MR images may be used to assess 3D architecture of trabecular bone, and the inclusion of some of the 3D architectural measures provides an improved assessment of biomechanical properties. Further studies are clearly warranted to establish the role of architecture in predicting overall bone quality, and the role of trabecular architecture measures in clinical practice. (ABSTRACT TRUNCATED)

Anatomy, Cross-Sectional↗
PubMed2003

On the design of a generic and scalable multilayer software architecture for data flow management in the intensive care unit.

OBJECTIVES: The current Intensive Care Information Systems (IC-ISs) collect and store monitoring data in on automated way and can replace all paper forms by an electronic equivalent, resulting in a paperless ICU. Future development of IC-ISs will now have to focus on bedside clinical decision support. The current IC-ISs are data-driven systems, with a two-layer software architecture. This software architecture is hardly maintainable and probably not the most optimal architecture to make the transition towards future systems with-decision support. The aim of this research was to address the design of an alternative software architecture based on new paradigms. METHODS: State-of-the art component, middleware and agent technology were deployed to design and implement a software architecture for ICU data flow management. RESULTS: An advanced multi-layer architecture for efficient data flow management in the ICU has been designed. The architecture is both generic and scalable, which means that it neither depends on a particular ICU nor on the deployed monitoring devices. Automatic device detection and Graphical User Interface generation are taken into account. Furthermore, a demonstrator has been developed as a proof that the proposed conceptual software architecture is feasible in practice. The core of the new architecture consists of Bed Decision Agents (BDAs). The introduction of BDAs, who perform specific dedicated tasks, improves the adaptability and maintainability of the future very complex IC-ISs. CONCLUSIONS: A software architecture, based on component, middleware and agent technology, is feasible and offers important advantages over the currently used two-layer software architecture.

Computer Systems↗
PubMedDate not supplied

Medical volume visualization on general-purpose parallel architectures.

Parallel volume visualization is of interest to a variety of application areas since current single-processor systems fall short in interactively rendering complex, large-sized datasets. This article presents a survey of volume-visualization methods on general-purpose parallel architectures, with special attention being paid to medical imaging applications. First, the various approaches to volume visualization are briefly discussed, followed by a description of relevant aspects of parallel architectures. Next, the implications of the various architectures are illustrated on the basis of a number of existing implementations of visualization algorithms on parallel architectures and their results. For parallel volume visualization, multiple instruction, multiple data (MIMD) architectures are found to be superior to single instruction, multiple data (SIMD) architectures. The latter type suffers from a lack of performance as well as flexibility. For most applications of interactive volume visualization, including the important area of medical imaging, shared memory MIMD architectures are preferred over distributed memory MIMD architectures. The ease of programming of shared memory architectures allows existing algorithms to be readily implemented without loss of performance or flexibility.

Algorithms↗
PubMed2000

Estimation of the architectural properties of cortical bone using peripheral quantitative computed tomography.

We assessed the volumetric bone mineral density (vBMD) and cross-sectional architecture of cortical bone at the distal radius by peripheral quantitative computed tomography (pQCT). The volumetric bone mineral density [integral bone mineral density (BMDi), trabecular bone mineral density (BMDt) and cortical with subcortical bone mineral density (BMDsc)] and the architectural parameters [cortical bone area (CBA), cortical thickness (C-th), moment of inertia (Im) and polar moment of inertia (Ip)] were measured in 115 healthy premenopausal women, 48 osteoporotic postmenopausal women and 78 age-matched healthy postmenopausal women. Age-matched healthy women had higher values of vBMD and architectural parameters at the distal radius than osteoporotic women. Premenopausal women had higher values of vBMD and architectural parameters at the distal radius than postmenopausal women. The differences in the architectural parameters between age-matched healthy women and osteoporotic women were more pronounced when only the high density area (threshold 0.70 cm(-1)) was included. However, the differences in architectural parameters between premenopausal women and postmenopausal women were significant using even the lowest threshold value of 0.50 cm(-1) in the calculation. Receiver operating characteristic (ROC) curves were constructed and the areas under the curves calculated to evaluate the discriminating power of vBMD and architectural parameters. Comparison of the different ROC curves showed no statistical significance. In conclusion, our results suggest that both the density and mass distribution of the radius were clearly different between the healthy women and osteoporotic women. The differences in architectural parameters were more useful for studying the pathophysiology of osteoporosis than for contributing to the diagnosis. Determination of the cross-sectional mass distribution of bone combined with BMD should offer more information than BMD alone in the study of the pathophysiology of osteoporosis.

Adult↗
PubMed2001

Quantitative ultrasound and trabecular architecture in the human calcaneus.

Relationships between quantitative ultrasound (QUS), density (bone volume density [BV/TV]), and trabecular architecture were investigated in 69 calcaneal cancellous bone cubes. Ultrasound signal velocity, phase velocity, attenuation, and broadband ultrasonic attenuation (BUA) measurements were made along the mediolateral axis. Density and architectural parameters were measured using microcomputed tomography (microCT). Density yielded the best correlations with QUS (r2 = 73-77%). Of the individual architectural parameters, correlations with QUS were highest for the Structure Model Index (SMI), a parameter quantifying the relative proportion of rods and plates (r2 = 57-63%). After adjustment for density, significant associations with QUS remained for SMI, trabecular spacing (Tb.Sp), and trabecular number (Tb.N), although the variance in QUS attributable uniquely to individual architectural parameters was at best 4%. In multivariate regression models, combinations of density and architectural parameters explained 76-82% of the variance in QUS, representing an r2 increase of, at most, 8% compared with using density alone. However, multivariate models using combinations of architectural parameters alone (i.e., density excluded) also had a good predictive ability for QUS (r2 = 73-81%). Thus, although these data show modest but significant density-independent relationships between QUS and trabecular architecture in the human calcaneus for the first time, the causal relationships behind the variation in acoustic properties remain obscure. Given the relative weakness and complexity of the emerging associations between QUS and architecture, it is prudent to regard QUS measurements in calcaneal bone primarily as an indicator of bone density.

Adult↗
PubMed2002

Risedronate preserves trabecular architecture and increases bone strength in vertebra of ovariectomized minipigs as measured by three-dimensional microcomputed tomography.

Risedronate reduces the risk of new vertebral fractures up to 70% within 1 year of treatment in patients with osteoporosis. Both increases in bone mass and preservation of bone architecture are thought to contribute to antifracture effects. Our objectives were to determine the effects of risedronate on trabecular bone mass and architecture and to determine the relative contributions of mass and architecture to strength in the vertebra of ovariectomized (OVX) minipigs. The minipigs were OVX at 18 months of age and were treated daily for 18 months with either vehicle or risedronate at doses of 0.5 mg/kg per day or 2.5 mg/kg per day. The three-dimensional (3D) bone architecture of the L4 vertebral cores of Sinclair S1 minipigs was evaluated by 3D microcomputed tomography (muCT). Compared with the OVX control, the vertebral bone volume (bone volume/tissue volume [BV/TV]) was higher in both treated groups (p < 0.05). The architectural changes were more significant at the 2.5-mg/kg dose and were more prevalent at the cranial-caudal ends compared with the midsection. At the higher dose, the trabecular thickness (Tb.Th), trabecular number (Tb.N), and connectivity were higher, and marrow star volume (Ma.St.V) and trabecular separation (Tb.Sp) were lower (p < 0.05). The trabecular separation variation index (TSVI), a new measure to approximate structural variations, was smaller in the 2.5-mg/kg-treated group (p < 0.05). In this group, a significant preservation of trabeculae orthogonal to the cranial-caudal axis was confirmed by a decrease in the degree of anisotropy (DA) and an increase in the percent Cross-strut (% Cross-strut; p < 0.05). Both normalized maximum load (strength) and normalized stiffness of the same vertebral cores were higher in the 2.5-mg/kg risedronate group compared with the OVX group (p < 0.05). BV/TV alone could explain 76% of the variability of the bone strength. The combination of bone volume and architectural variables explained >90% of the strength. The study showed that risedronate preserved trabecular architecture in the vertebra of OVX minipigs, and that bone strength is tightly coupled to bone mass and architecture.

Animals↗
PubMed2003

Documentation and three-dimensional modelling of human soleus muscle architecture.

The purpose of this study was to visualize and document the architecture of the human soleus muscle throughout its entire volume. The architecture was visualized by creating a three-dimensional (3D) manipulatable computer model of an entire cadaveric soleus, in situ, using B-spline solid to display muscle fiber bundles that had been serially dissected, pinned, and digitized. A database of fiber bundle length and angle of pennation throughout the marginal, posterior, and anterior soleus was compiled. The computer model allowed documentation of the architectural parameters in 3D space, with the angle of pennation being measured relative to the tangent plane of the point of attachment of a fiber bundle. Before this study, the only architectural parameters that have been recorded have been 2D. Three-dimensional reconstruction is an exciting innovation because it makes feasible the creation of an architectural database and allows visualization of each fiber bundle in situ from any perspective. It was concluded that the architecture is non-uniform throughout the volume of soleus. Detailed architectural studies may lead to the development of muscle models that can more accurately predict interaction between muscle parts, force generation, and the effect of pathologic states on muscle function.

Cadaver↗