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Results for “computational frameworks”

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At least 271 records · Page 15Linked to original sources

PubMed2002

[CRANIO--development of a system for computer- and robot-assisted craniotomy].

In the framework of the DFG project CRANIO, we are dealing with the problems of computer-assisted planning and robot-assisted realization of craniotomy, with optional skull reconstruction. A CT dataset was obtained from a phantom skull model and basic operation planning as well as different registration methods were performed. As one option it is possible to mill a contour on the skull or even to remove the entire area with a robot-guided microsurgical milling tool. In this context, work space tests were performed with a hexapod parallel robot. The milling of any contour geometry could be realized with different tool angles using the existing CRIGOS robot system without additional axes.

Computer Simulation↗

PubMed2000

Federation of the Person Identification Service between enterprises.

The Person Identification Service (PIDS) is a standard that has been adopted by the Object Management Group for managing identities of persons within a particular domain. That standard includes an interface that supports the ability to connect multiple PIDS servers together in a federated manner. The specification leaves great flexibility as to how to accomplish the federation. In this paper, we examine some of the federated approaches being considered by the Government Computer-based Patient Record Framework (G-CPR) project and discuss their advantages and disadvantages and the details of a specific, scalable approach to federation.

Government Agencies↗

PubMed1991

Population density and development potential in rural Zimbabwe: an assessment based on the 1969 and 1982 censuses.

"Based on 1969 and 1982 census data, this paper examines the spatial association between high rural population density and development potential in Zimbabwe and its significance for national development policy. A 1982 grid cell density map was compiled on the same geographical frame as an existing 1969 density map, yielding an intercensal density change map. A land classification map and a composite map of development constraints were rasterized on the same spatial framework and subjected to computer analysis. Areas of critically high (and generally increasing) densities showed strong spatial associations with areas of severe development constraints...."

Africa↗

PubMed2002

[Registration statistical program for the Rehabilitation Center for Patients with Cleft Lip and Palate in Uzbekistan].

The authors suggest an information computer support within the framework of a complex system for the diagnosis and treatment of patients with cleft lip and palate. This program will ensure operative information exchange for specialists of various spheres. Such information, united in the data base, will become the base for creation of a universal system of complex rehabilitation of patients with cleft lip and palate.

Cleft Lip↗

PubMed1996

A desktop image processing system for computer-assisted orthopedic surgery (DISOS).

Within the framework of our research activities in orthopedic surgery a PC-based imageprocessing system for the processing of x-ray computer-tomographic data has been developed. The system is used as a work platform for the investigations concerning interaction modalities, strategies and techniques for an efficient planning and execution of surgical interventions in orthopedic surgery by means of individual templates. The method of individual templates has been presented in /1,2/ and will not be subject of this paper.

Computer Peripherals↗

PubMed1998

Constrained optimization for neural map formation: a unifying framework for weight growth and normalization.

Computational models of neural map formation can be considered on at least three different levels of abstraction: detailed models including neural activity dynamics, weight dynamics that abstract from the neural activity dynamics by an adiabatic approximation, and constrained optimization from which equations governing weight dynamics can be derived. Constrained optimization uses an objective function, from which a weight growth rule can be derived as a gradient flow, and some constraints, from which normalization rules are derived. In this article, we present an example of how an optimization problem can be derived from detailed nonlinear neural dynamics. A systematic investigation reveals how different weight dynamics introduced previously can be derived from two types of objective function terms and two types of constraints. This includes dynamic link matching as a special case of neural map formation. We focus in particular on the role of coordinate transformations to derive different weight dynamics from the same optimization problem. Several examples illustrate how the constrained optimization framework can help in understanding, generating, and comparing different models of neural map formation. The techniques used in this analysis may also be useful in investigating other types of neural dynamics.

Animals↗

PubMed1995

Coevolutionary computation.

This article proposes a general framework for the use of coevolution to boost the performance of genetic search. It combines coevolution with yet another biologically inspired technique, called lifetime fitness evaluation (LTFE). Two unrelated problems--neural net learning and constraint satisfaction--are used to illustrate the approach. Both problems use predator-prey interactions to boost the search. In contrast with traditional "single population" genetic algorithms (GAs), two populations constantly interact and co-evolve. However, the same algorithm can also be used with different types of co-evolutionary interactions. As an example, the symbiotic coevolution of solutions and genetic representations is shown to provide an elegant solution to the problem of finding a suitable genetic representation. The approach presented here greatly profits from the partial and continuous nature of LTFE. Noise tolerance is one advantage. Even more important, LTFE is ideally suited to deal with coupled fitness landscapes typical for coevolution.

Algorithms↗

PubMedDate not supplied

Consumer informatics in chronic illness.

OBJECTIVE: To explore the informatic requirements in the home care of chronically ill patients. DESIGN: A number of strategies were deployed to help evoke a picture of home care informatics needs: A detailed questionnaire evaluating informational needs and assessing programmable technologies was distributed to a clinic population of parents of children with cancer. Open ended questionnaires were distributed to medical staff and parents soliciting a list of questions asked of medical staff. Parent procedure training was observed to evaluate the training dialog, and parents were observed interacting with a prototype information and education computer offering. RESULTS: Parents' concerns ranged from the details of managing day to day, to conceptual information about disease and treatment, to management of psychosocial problems. They sought information to solve problems and to provide emotional support, which may create conflicts of interest when the material is threatening. Whether they preferred to be informed by a doctor, nurse, or another parent depended on the nature of the information. Live interaction was preferred to video, which was preferred to text for all topics. Respondents used existing technologies in a straightforward way but were enthusiastic about the proposed use of computer technology to support home care. Multimedia solutions appear to complement user needs and preferences. CONCLUSION: Consumers appear positively disposed toward on-line solutions. On-line systems can offer breadth, depth and timeliness currently unattainable. Patients should be involved in the formation and development process in much the same way that users are involved in user-centered computer interface design. A generic framework for patient content is presented that could be applied across multiple disorders.

Adaptation, Psychological↗

PubMed1999

A framework and tools for authoring, editing, documenting, sharing, searching, navigating, and executing computer-based clinical guidelines.

With the spread of managed care and integrated delivery networks, an increased emphasis has been placed on the cost-effectiveness of clinical practices. The need has been recognized to use guidelines to support education, and to integrate them into clinical practice. A specification for guideline representation that would facilitate computer-based clinical guideline sharing has been developed by the InterMed Collaboratory. Called GLIF (GuideLine Interchange Format), this specification and its proposed extensions have been the basis for our implementation of a framework and suite of integrated software tools for guideline authoring and editing, packaging in XML, Internet distribution, navigation, eligibility determination, and automatic execution.

Eligibility Determination↗

PubMed1999

Merging multiple institutions: information architecture problems and solutions.

Amalgamating organizations face great challenges when trying to merge their formerly separate information systems. An architectural approach is essential in order to understand the business process and data implications of the new organization's business decisions and application choices. HL7 is useful as a common messaging standard, but does not help to reconcile conflicting local identifier coding systems. The Information Services department has an important role in catalyzing decisions about inconsistent business processes and conflicting universal coding systems within an enterprise framework.

Computer Systems↗

PubMed2001

End-user support: a necessary issue in the implementation and use of EPR systems.

A successful integration of an IT-system is dependent not only of the quality of the information and the user interface features of the system but also of the organizations ability to support the users learning process. As IT is becoming more and more pervasive in the Health Care sector as such there is a need for a systematic approach to the question on how to support end-users. Based on an empirical study of an implementation process in a Danish Primary Health Care Services the concept of end-user support is discussed and it is argued that there is a need for a distinction between different kinds of support depending of the type of activity involved. First the organizations strategy for learning when the system was implemented is described. The evaluation of the learning strategy revealed that there was a need for different kinds of knowledge involving qualitatively different kinds of learning. Second the area of end-user support is discussed and it is argued that the common understanding of end-user support as something provided by DP staff, vendors or manuals are to narrow. Third a more differentiated way of thinking of support that link the need for different kind of knowledge and learning processes to different kinds of support is proposed. Finally Activity Theory is put forward as a possible basis that provide the opportunity of discussing issues belonging to different kinds of end-user support within an integrated framework.

Computer User Training↗

PubMedDate not supplied

Medical informatics and the science of cognition.

Recent developments in medical informatics research have afforded possibilities for great advances in health care delivery. These exciting opportunities also present formidable challenges to the implementation and integration of technologies in the workplace. As in most domains, there is a gulf between technologic artifacts and end users. Since medical practice is a human endeavor, there is a need for bridging disciplines to enable clinicians to benefit from rapid technologic advances. This is turn necessitates a broadening of disciplinary boundaries to consider cognitive and social factors pertaining to the design and use of technology. The authors argue for a place of prominence for cognitive science. Cognitive science provides a framework for the analysis and modeling of complex human performance and has considerable applicability to a range of issues in informatics. Its methods have been employed to illuminate different facets of design and implementation. This approach has also yielded insights into the mechanisms and processes involved in collaborative design. Cognitive scientific methods and theories are illustrated in the context of two examples that examine human-computer interaction in medical contexts and computer-mediated collaborative processes. The framework outlined in this paper can be used to refine the process of iterative design, end-user training, and productive practice.

Cognitive Science↗

PubMed1992

[Acute abdominal pain--standardized findings as diagnostic support. Results of a prospective multicenter intervention study and testing of a computer-assisted diagnosis system].

Despite powerful diagnostic tools (e.g. ultrasound, special laboratory investigations), the diagnosis of acute abdominal pain is still a considerable problem. Several studies in the UK have shown that the diagnostic accuracy can be improved by structured and standardized history taking and clinical examination and by computer-aided diagnosis. In the framework of a concerted action of the European Community we have conducted a prospective multicenter interventional trial comparing two consecutive phases: a) a baseline phase in clinical routine without additional intervention, b) a test phase with structured and standardized history and clinical examination (questionnaire, documentation programme). In addition, a computer-aided diagnostic system developed in the UK was applied to the cases in the test phase. Outcome criteria were the diagnostic accuracy of the initial and the final examiner, the perforated appendix rate, the negative appendectomy rate, the negative laparotomy rate and the rates of diagnostic errors with missing indication to operation and of delayed urgent operations. No differences could be found between the phases with respect to the outcome criteria. In the baseline phase (test phase) diagnostic accuracy was 59% (59%), diagnostic accuracy after investigation (senior examiner) was 77% (78%), perforated appendix rate was 11% (16%), negative appendectomy rate was 13% (15%), negative laparotomy rate was 7% (8%), the rate of missed urgent indications to operation was 1.1% (1.9%) and the rate of delayed urgent operations was 3.4% (2.4%). Major differences between the centers were recorded. Computer-aided diagnosis resulted in a diagnostic accuracy of 51%. The introduction of structured and standardized history taking and clinical examination has not brought any improvement of the good results in clinical routine. It is doubtful, whether existing systems of computer-aided diagnosis are able to significantly decrease the still remaining error rate of 20%.

Abdomen, Acute↗

PubMed2001

Reinventing patient-centered computing for the twenty-first century.

Despite evidence over the past decade that patients like and will use patient-centered computing systems in managing their health, patients have remained forgotten stakeholders in advances in clinical computing systems. We present a framework for patient empowerment and the technical realization of that framework in an architecture called CareLink. In an evaluation of the initial deployment of CareLink in the support of neonatal intensive care, we have demonstrated a reduction in the length of stay for very-low birthweight infants, and an improvement in family satisfaction with care delivery. With the ubiquitous adoption of the Internet into the general culture, patient-centered computing provides the opportunity to mend broken health care relationships and reconnect patients to the care delivery process. CareLink itself provides functionality to support both clinical care and research, and provides a living laboratory for the further study of patient-centered computing.

Humans↗

PubMed1998

A proposed bioactive conformation of peptide T.

The conformational profiles of Peptide T, (5-8)Peptide T, [Abu5](4-8)Peptide T and (4-8)Peptide T were computed independently to assess the geometrical characteristics of the bioactive conformation of Peptide T. The conformational profiles of the peptides were computed within the molecular mechanics framework using an effective dielectric constant of 80. The conformational space was thoroughly sampled using an iterative simulated annealing protocol. The bioactive conformation was assessed by pairwise cross comparisons of each of the unique low energy conformations found for each of the different analogs studied. After a putative bioactive conformation was selected, in order to further validate our hypothesis the conformational profile of the potent compound cyclo(Thr-Thr-Asn-Tyr-Thr-Asp) was computed and the putative bioactive conformation was found. The conformation exhibits a pseudo beta-turn involving the side chain of Thr5 and the carbonyl oxygen of Tyr7 forming a C12 ring.

Amino Acid Sequence↗

PubMedDate not supplied

A neurocomputational approach to delusions.

Neuronal networks process information in parallel. The cortex can be viewed as a computational surface that creates and maintains dynamic maps of representations of important sensorimotor and higher-level aspects of the environment and the organism. Its functions can be modeled by a particular type of neural network, the self-organizing feature map. Most importantly, representations of information in the cortex and in these maps have been demonstrated to change dynamically according to the salience and frequency of the input. This feature is referred to as neuroplasticity. The fact that general operational characteristics of computational maps in the cortex can be fine-tuned according to specific processing needs is referred to as neuromodulation. Within this framework of cortical maps and their computational models, acute and chronic delusions are discussed in terms of neuromodulation and neuroplasticity. This neurocomputational approach provides new insights into the phenomena in question, is detailed enough to allow empirical testing, and has therapeutic implications.

Brain↗

PubMed1981

A computer model for epidermal cellular interactions.

A model has been constructed of an assembly of mammalian epidermal cells. The model, simulated by computer, has served as a framework by which experiments can be performed "in machina". Relationships between the various parameters considered have been established. Hypotheses referring to the time at which cells leave the basal layer, and to the simultaneous occurrence of folded basal layer and of a significant number of vertical mitosis in some hyperplastic conditions have been implemented and examined.

Animals↗

PubMed1993

Virtual trajectory and stiffness ellipse during multijoint arm movement predicted by neural inverse models.

We predict the virtual trajectories and stiffness ellipses during multijoint arm movements by computer simulations. A two-link manipulator with four single-joint muscles and two double-joint muscles is used as a model of the human arm. Physical parameters of the model are derived from several experimental data. Among them, special emphasis is put on low values of the dynamic hand stiffness recently measured during single-joint and multijoint movements. The feedback-error-learning scheme to acquire the inverse dynamics model and the inverse statics model is utilized for this prediction. The virtual trajectories are much more complex than the actual trajectories. This indicates that planning the virtual trajectory is as difficult as solving the inverse dynamics problem for medium and fast movements, and simply falsifies the advocated computational advantage of the virtual trajectory control hypothesis. Thus, we conclude that learning inverse models is essential even in the virtual trajectory control framework. Finally, we propose a new computational model to learn the complicated shape of the virtual trajectories by integrating the virtual trajectory control and the feedback-error-learning scheme.

Arm↗