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Multiresolution segmentation of three-dimensional medical images using mathematical morphology techniques.

A semi-automatic method for three-dimensional segmentation of medical images is proposed. A multiresolution representation is achieved through the application of morphological filters, which assures causality for image extrema. This allows for a compact scale space representation, in which each extremum is assigned a scale value. Interactive selection of the interesting extrema of the image is carried out, aided by this scale information and other relevant features. Extrema selected are then used as markers in three-dimensional watersheds calculation. The system has been developed and tested under low cost platforms, and can be the base for totally automatic, knowledge based segmentation systems.

Artificial Intelligence↗

[Campaign in order to attract nursing students].

During the late 1940s there was a shortage of nurses in Denmark. The Danish Council of Nurses (DSR) initiated a campaign in order to attract nursing students. This and other campaigns show the dilemmas within the nursing profession in this period. At the same time discussions on the future of the nursing profession took place and ministerial committees worked on the establishment of a countrywide uniform training for nurses. The campaigns highlighted on one side the traditions in the nursing profession, i.e. the feminine ability for care, which is based upon the feminine distinctive character. On the other side the campaigns pointed towards the future nursing profession, which is based upon professionalism and knowledge based upon schooling.

Advertising↗

Age-related macular degeneration: the current understanding of the status of clinicopathology, diagnosis and management.

BACKGROUND: This paper represents an up-to-date review of the current thoughts regarding the etiopathogenesis and management of the various varieties of age-related macular degeneration (ARMD). METHODS: Included is a look at the epidemiology as well as the clinicopathologic basis for the development of the degenerative process. CONCLUSIONS: The clinicopathologic basis for development of ARMD is divided into drusen, lipofuscin development, solar radiation effects, photochemical damage and mediation by antioxidants, choroidal neovascularization, scarification, and retinal pigment epithelial detachment. The clinical presentation of both non-exudative and exudative ARMD is discussed with synopses of the mimickers of both outlined in the text. RESULTS: Current accepted methods of therapy are discussed including; laser intervention, surgical removal of membranes, and investigational modes of treatment including antioxidants. Specific management protocol is discussed based on the current knowledge base.

Aged↗

Diagnostics and a qualitative model.

First generation expert systems were using shallow knowledge based on heuristic information to solve a diagnostic problem. This approach has many disadvantages, which can be avoided by using deep knowledge. Diagnostic reasoning based on deep knowledge is called model-based diagnostics. Recently, the use of qualitative modeling in relation to deep knowledge in expert systems has become increasingly important. The main purpose of our contribution is to present the model-based diagnostic approach at a formal level. The originality of the presented formalization is the concept of the diagnostic space, the characterization of the minimal diagnoses, and the measurement. The formalization serves as the theoretical background to prove our view to the design of qualitative system models and to establish the diagnostic architecture called DISY. The qualitative system model in our diagnostic approach needs not to be specially adopted for use in the diagnostic domain. The only requirement is that it must simulate the system behavior expressed by normal or abnormal functioning of its components. Proposed DISY architecture is not complex and simply takes into an account the previous diagnostic result to obtain a new one from the additional observation-measurement (medical tests or examinations) of the system.

Decision Support Techniques↗

Information networks and their impact upon medicine.

There is an information explosion and geometric growth of knowledge in medicine. The individual physician finds himself having great difficulty coping with this ever increasing knowledge base. The recognition of a gap in such knowledge; while frustrating, may also have a direct impact upon patient care. Computer technology, information retrieval modalities, and teleprocessing between remote locations has been viewed as a partial solution to this issue. Microcomputers and their associated elements are able to be used as information retrieval devices tapping into vast reservoirs of data and information on all aspects of medicine. Physicians faced with this new technology generally have little or no training, experience or understanding of how best to harness the power of computers to meet their individual practice requirements. This article provides a basic overview of those computer concepts that relate specifically to information retrieval from large data bases to individual physician's offices, regardless of their location. The article explores the specific hardware and software components that are required for effective linkage into a computer based information network for medicine. The article concludes with an overview of the work done by the American Academy of Dermatology in this area to satisfy informational needs of its members in coping with the ever increasing knowledge base of medicine.

Computer Communication Networks↗

Evidence-based development of a diagnosis-dependent therapy planning system and its implementation in modern diagnostic software.

The prerequisite for structured individual therapy of craniomandibular dysfunctions is differential diagnostics. Suggestions for the structured recording of findings and their structured evaluation beyond the global diagnosis of "craniomandibular disorders" have been published. Only this structured approach enables computerization of the diagnostic process. The respective software is available for use in practice (CMDcheck for CMD screening, CMDfact for the differential diagnostics). Based on this structured diagnostics, knowledge-based therapy planning is also conceivable. The prerequisite for this would be a model of achieving consensus on the indicated forms of therapy related to the diagnosis. Therefore, a procedure for evidence-based achievement of consensus on suitable forms of therapy in CMD was developed first in multicentric cooperation, and then implemented in corresponding software. The clinical knowledge of experienced specialists was included consciously for the consensus achievement process. At the same time, anonymized mathematical statistical evaluations were used for control and objectification. Different examiners form different departments of several universities working independently of one another assigned the theoretically conceiveable therapeutic alternatives to the already published diagnostic scheme. After anonymization, the correlation of these assignments was then calculated mathematically. For achieving consensus in those cases for which no agreement initally existed, agreement was subsequently arrived at in the course of a consensus conference on the basis of literature evaluations and the discussion of clinical case examples. This consensus in turn finally served as the basis of a therapy planner implemented in the above-mentioned diagnostic software CMDfact. Contributing to quality assurance, the principles of programming this assistant as well as the interface for linking into the diagnostic software are documented and also published here.

Clinical Protocols↗

ABMS' Maintenance of Certification: the challenge of continuing competence.

The American Board of Medical Specialties, since its inception in 1933 as the Advisory Board for Medical Specialties, is concerned with the education, training and certification of physician specialists. Although not perfect, the initial certification process is quite good and accomplishes its intended purpose. However, initial certification is based on a primarily knowledge-based "snapshot." The newly developed Maintenance of Certification Program will evaluate the competencies, medical knowledge, patient care, interpersonal and communication skills, professionalism, practice-based learning and improvement and systems-based practices believed to be necessary and sufficient for certified physicians to have and maintain throughout their entire professional career. Furthermore, the process will focus on education and assessment to encourage continuous quality improvement in clinical practice.

Advisory Committees↗

Stability improvement of antibodies for extracellular and intracellular applications: CDR grafting to stable frameworks and structure-based framework engineering.

By combining the knowledge gained from an analysis of the biophysical properties of natural antibody variable domains, the effects of mutations obtained in directed evolution experiments, and the detailed structural comparison of antibodies, it has now become possible to engineer antibodies for higher thermodynamic stability and more efficient folding. This is particularly important when antibodies are to be used under conditions where the disulfide bonds cannot form, i.e., in intracellular applications (as "intrabodies"). We describe in detail two methods for the knowledge-based improvement of antibody stability and folding efficiency. While CDR grafting from a non-human to the most closely related human antibody framework is an established technique to reduce the immunogenicity of a therapeutic antibody, CDR grafting for stabilization implies the use of a more distantly related acceptor framework with superior biophysical characteristics. The use of such dissimilar frameworks requires particular attention to antigen contact residues outside the classical CDR definition and to residues capable of indirectly affecting the conformation of the antigen binding site. As a second alternative, the stability of a suboptimal framework can be improved by the introduction of point mutations designed to optimize key residue interactions. We describe the analysis methods used to identify such point mutations, which can be introduced all at once, while maintaining the framework features necessary for antigen binding. These rational approaches render the continued "rediscovery" of certain mutations by directed evolution unnecessary, but they can also be used in conjunction with such methods to discover even better molecules.

Animals↗

Method for segmenting chest CT image data using an anatomical model: preliminary results.

We present an automated, knowledge-based method for segmenting chest computed tomography (CT) datasets. Anatomical knowledge including expected volume, shape, relative position, and X-ray attenuation of organs provides feature constraints that guide the segmentation process. Knowledge is represented at a high level using an explicit anatomical model. The model is stored in a frame-based semantic network and anatomical variability is incorporated using fuzzy sets. A blackboard architecture permits the data representation and processing algorithms in the model domain to be independent of those in the image domain. Knowledge-constrained segmentation routines extract contiguous three-dimensional (3-D) sets of voxels, and their feature-space representations are posted on the blackboard. An inference engine uses fuzzy logic to match image to model objects based on the feature constraints. Strict separation of model and image domains allows for systematic extension of the knowledge base. In preliminary experiments, the method has been applied to a small number of thoracic CT datasets. Based on subjective visual assessment by experienced thoracic radiologists, basic anatomic structures such as the lungs, central tracheobronchial tree, chest wall, and mediastinum were successfully segmented. To demonstrate the extensibility of the system, knowledge was added to represent the more complex anatomy of lung lesions in contact with vessels or the chest wall. Visual inspection of these segmented lesions was also favorable. These preliminary results suggest that use of expert knowledge provides an increased level of automation compared with low-level segmentation techniques. Moreover, the knowledge-based approach may better discriminate between structures of similar attenuation and anatomic contiguity. Further validation is required.

Computer Simulation↗

Clinical assessment of hope.

In recent years, nurse researchers have given more attention to the role that hope plays in health and illness. While this research adds to the knowledge base about hope, that this knowledge may become too theoretical and difficult to apply in the clinical setting. Based on a study of hope conducted with community-based older adults, an analysis of the hope instruments used in this study, and ongoing clinical experiences, a guide for the clinical assessment of hope is proposed.

Health Status↗