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At least 253 records · Page 14Linked to original sources
PubMed2000

Global water resources: vulnerability from climate change and population growth.

The future adequacy of freshwater resources is difficult to assess, owing to a complex and rapidly changing geography of water supply and use. Numerical experiments combining climate model outputs, water budgets, and socioeconomic information along digitized river networks demonstrate that (i) a large proportion of the world's population is currently experiencing water stress and (ii) rising water demands greatly outweigh greenhouse warming in defining the state of global water systems to 2025. Consideration of direct human impacts on global water supply remains a poorly articulated but potentially important facet of the larger global change question.

Agriculture↗
PubMed1997

Tele-education: the virtual medical laboratory.

The virtual medical laboratory (VML) was conceived to provide an Internet-accessible resource, offering access for clinicians and scientists to an invaluable data archive at the institute of Laryngology and Otology, London. The Institute is home to the largest collection of temporal bone, laryngeal, skull and sinus sections in Europe. The skull and sinus collections include an extensive section consisting of animal material. These were contributions from zoos around the world. Over the last 50 years, samples have been carefully sectioned and stained by specialized technicians to produce histology slices of most regions of the head and neck. The aim of the project is to create a virtual medical laboratory, which will provide access to archived histological material as well as computerized tomography and magnetic resonance data. Central to this aim is the reconstruction of the internal anatomy of the temporal bone from two-dimensional histology slices, to create three-dimensional views that can be used for anatomical simulation and surgical training in otolaryngology. State-of-the-art three-dimensional reconstruction and rendering technology allows us to develop such a model. Computer-generated simulation could be made available to all hospitals in which otolaryngology is practised, via digital communication networks. We aim to develop core technology in our own specialty that is applicable to other fields of higher education, which have not been exposed to such modern teaching modalities. This has the potential to become an invaluable teaching resource for anatomists, surgeons and other scientists.

Computer Communication Networks↗
PubMed1998

Planning and cost analysis of digital radiography services for a network of hospitals (the Veterans Integrated Service Network).

This study analysed the design and cost of a picture archiving and communications system (PACS), computerized radiography (CR) and a wide-area network for teleradiology. The Desert Pacific Healthcare Network comprises 10 facilities, including four tertiary medical centres and one small hospital. Data were collected on radiologists' workloads, and patient and image flow within and between these medical centres. These were used to estimate the size and cash flows associated with a system-wide implementation of PACS, CR and teleradiology services. A cost analysis model was used to estimate the potential cost savings in a filmless radiology environment. ATM technology was selected as the communications medium between the medical centres. A strategic plan and business plan were successfully developed. The cost model predicted the cost-effectiveness of the proposed PACS/CR configuration within four to six years, if the base costs were kept low. The experience gained in design and cost analysis of a PACS/teleradiology network will serve as a model for similar projects.

California↗
PubMed2005

Cellular telephone interference with medical equipment.

OBJECTIVE: To assess the potential electromagnetic interference (EMI) effects that new or current-generation cellular telephones have on medical devices. MATERIAL AND METHODS: For this study, performed at the Mayo Clinic in Rochester, Minn, between March 9, 2004, and April 24, 2004, we tested 16 different medical devices with 6 cellular telephones to assess the potential for EMI. Two of the medical devices were tested with both new and old interface modules. The 6 cellular telephones chosen represent the different cellular technology protocols in use: Code Division Multiple Access (2 models), Global System for Mobile communications, Integrated Digital Enhanced Network, Time Division Multiple Access, and analog. The cellular telephones were tested when operating at or near their maximum power output. The medical devices, connected to clinical simulators during testing, were monitored by observing the device displays and alarms. RESULTS: Of 510 tests performed, the incidence of clinically important interference was 1.2%; EMI was Induced in 108 tests (21.2%). Interference occurred in 7 (44%) of the 16 devices tested. CONCLUSIONS: Cellular telephones can interfere with medical equipment. Technology changes in both cellular telephones and medical equipment may continue to mitigate or may worsen clinically relevant interference. Compared with cellular telephones tested in previous studies, those currently in use must be closer to medical devices before any interference is noticed. However, periodic testing of cellular telephones to determine their effects on medical equipment will be required.

Cell Phone↗
PubMed1997

Medical emergency aid through telematics: design, implementation guidelines and analysis of user requirements for the MERMAID project.

MERMAID is an EU financed telemedicine project with global reach and 24-hour, multilingual capability. It aspires to provide a model for the provision of health care services based on the electronic transmission of medical information, via ISDN based videoconferencing. This model will not be limited to medical diagnostics but it will encompass all cases where the actual delivery of health care services involves a patient who is not located where the provider is. Its implementation requires the commissioning of an expensive telecommunications infrastructure and the exploration of a number of solutions. In fact, all categories of telemedical applications (audio and video conferencing, multimedia communications, flat file and image transfer with low, medium and high bandwidth data requirements) will be considered while the full range of network choices (Digital land lines, Cellular/Wireless, Satellite and Broadband) will be tested in terms of cost/performance tradeoffs that are inherent to them and the developmental stage each of these options occupies in their in its life cycle. Finally, out that MERMAID utilises advanced land based line transmission technologies to aid the remote patient by making available the specialist care that is best suited in the particular case.

Emergency Medical Services↗
PubMed1987

Imaging forecast: tools of the future.

What will be the tools of radiology in the years ahead? If the manufacturing and government experts consulted by APPLIED RADIOLOGY are right, exciting years lie ahead. New imaging techniques, display capacity--including three-dimensional holograms--and digital image networks all await in the future.

Forecasting↗
PubMed1998

A convincing case for the provision of telemedicine services to ocean going vessels: the MERMAID paradigm.

MERMAID is an EU financed telemedicine project with global reach and 24-hour, multilingual capability. It aspires to provide a model for the provision of health care services based on the electronic transmission of medical information, via ISDN based videoconferencing. This model will not be limited to medical diagnostics but it will encompass all cases where the actual delivery of health care services involves a patient who is not located where the provider is. Its implementation requires the commissioning of an expensive telecommunications infrastructure and the exploration of a number of solutions. In fact, all categories of telemedical applications (audio and video conferencing, multimedia communications, flat file and image transfer with low, medium and high bandwidth data requirements) are considered while the full range of network choices (Digital land lines, Cellular/Wireless, Satellite and Broadband) are being tested in terms of cost/performance tradeoffs that are inherent to them and the developmental state each of these options occupies in their in its life cycle. Finally, out that MERMAID utilises advanced land based line transmission technologies to aid the remote patient by making available the specialist care that is best suited in the particular case.

Emergency Medical Services↗
PubMed2001

Georeferenced regional simulation and aquatic exposure assessment.

A simulation model system of the waste water pathways and the aquatic fate assessment is coupled to a discrete digitized river network. Temporal concentration distributions of down-the-drain chemicals are calculated from variable and uncertain input data and compared to monitoring data. The accuracy of the predictions are within a factor of three for the studied pilot catchments. Spatial distributions of the whole catchment give stochastic information on a regional basis for probabilistic risk assessments.

Computer Simulation↗
PubMedDate not supplied

[A telemedicine electrocardiography system based on the component-architecture soft].

The paper deals with a universal component-oriented architecture for creating the telemedicine applications. The worked-out system ensures the ECG reading, pressure measurements and pulsometry. The system design comprises a central database server and a client telemedicine module. Data can be transmitted via different interfaces--from an ordinary local network to digital satellite phones. The data protection is guaranteed by microchip charts that were used to realize the authentication 3DES algorithm.

Blood Pressure Determination↗
PubMed2002

Toward a quantitative analysis of skin lesion images.

Melanoma is the most dangerous form of skin cancer. Skin cancers, and particularly melanomas, can be easily cured if detected early. The regularity of the pigment network structure is a significant sign for early diagnosis of melanoma. We present here a quantitative analysis of the morphology of the pigment network structure. Our method is based on the extraction of the pigment network structure using digital image processing techniques. Once the network is extracted, it is possible to derive statistical indicators relative to its regularity or irregularity. We report experiments on a database of 14 images, showing the effectiveness of our method.

Diagnostic Imaging↗
PubMed1991

An initial assessment of the cost and utilization of the Integrated Academic Information System (IAIMS) at Columbia Presbyterian Medical Center.

The concept of "one stop information shopping" is becoming a reality at Columbia Presbyterian Medical Center (CPMC). The goal of our effort is to provide access to university and hospital administrative systems as well as clinical and library applications from a single workstation, which also provides utility functions such as word processing and mail. Since June 1987, CPMC has invested the equivalent of $23 million dollars to install a digital communications network that encompasses 18 buildings at seven geographically separate sites and to develop clinical and library applications that are integrated with the existing hospital and university administrative and research computing facilities. During June 1991, 2425 different individuals used the clinical information system, 425 different individuals used the library applications, and 900 different individuals used the hospital administrative applications via network access. If we were to freeze the system in its current state, amortize the development and network installation costs, and add projected maintenance costs for the clinical and library applications, our integrated information system would cost $2.8 million on an annual basis. This cost is 0.3% of the medical center's annual budget. These expenditures could be justified by very small improvements in time savings for personnel and/or decreased length of hospital stay and/or more efficient use of resources. In addition to the direct benefits which we detail, a major benefit is the ease with which additional computer-based applications can be added incrementally at an extremely modest cost.

Academic Medical Centers↗
PubMedDate not supplied

Progress in telepathology.

The basic principles, technical objectives and future aspects of telecommunication in pathology (telepathology) are discussed. Visual information, which is the usually the basic source of medical disease classification, and its transfer have to be distinguished from acoustic information, which is commonly of secondary, i.e. abstract nature. Visual telecommunication in pathology can be applied in five different aspects, namely: a) to create visual data bases, b) to be used in expert consultation, c) to combine morphological and clinical data, d) to quantitate morphological findings (DNA- measurements, etc.), and e) to install remote control microscopes. Depending upon the application, different technical prerequisites and constraints have to be taken into account: queries of visual data bases and expert consultations can be performed by use of "normal" telephone lines; combination of morphological and clinical data and quantitation of morphological data may need a digitized telephone network (ISDN), and the transfer of live images needed for application of remote control microscopes can only be performed by use of ISDN or broadband networks (optical fiber transmission systems, satellite communication, etc.). The experiences of various groups working in different aspects of telepathology are described.

Forecasting↗
PubMed1979

Spatial firing patterns of auditory neuron network modelling by computer simulation.

This communication examines, in digital computer simulated network, input signals and response patterns established at excitatory neurons' level i.e. the membrane potential of neuron soma. It is restricted to spatial patterns of the auditory neuron networks and time factor for nervous conduction and transmission is neglected compared with long maintained membrane potentials of neuron somas. The model analyzes the change in the spatial patterns of the membrane potential in the two dimensional networks of the auditory system. In order to evaluate the contribution of the various parameters, it is started that the simplest model has only one parameter, lateral inhibition. The other parameters are then added, one at a time, to successive models. The lateral inhibition is a necessary condition in the auditory nervous system if any sharpening of the response areas in the single neurons is to occur. A necessary condition for the validity of the model is that is should be applicable to the other senses such as vision and chemical patterns, taste. The threshold feature of auditory neurons aids in producing a sharpening in the neuron of the auditory relay nuclei. It does this clipping the spatial response patterns in one dimensional arrays of excitatory neurons. Recurrent inhibition seems a necessary condition in the sensory nervous system that any kinds of input signals are to be preserved over a wide range of stimulus intensity. In other words, this network has a wide dynamic range against any kinds of input signals. A simple self-recurrent negative feedback does not contribute to the sharpening, but more complex socalled averaged type does. A neuron network is capable of responding stably to stimuli with a wide range of intensity and with any kind of spatial patterns if there is a simple negative feedback mechanism. When there is no negative feedback, input signals soon disappear or saturate in the neuron network. Therefore, recurrent inhibition is the most important mechanism. Spontaneous activity appears to aid in the sharpening by providing a kind of contrast, that is by reducting the amount of activity in neurons adjacent to the excitatory area. Moreover, the effect of spontaneous activity in the model seems to make repples around the excitatory area and suggests that an introduction of activity at any stage of the networks, from whatever source for example reticulum formation and thalamus, might appreciably alter the response patterns at subsequent neuron network. This suggests that the mechanism of the consciousness that might be controlled by the thalamus and or reticular formation. These two dimensional neuron networks may be expanded to three dimensional neuron networks. The former might simulate the auditory nervous system while the latter might simulate the visual system.

Animals↗
PubMed1996

An improved shift-invariant artificial neural network for computerized detection of clustered microcalcifications in digital mammograms.

A shift-invariant artificial neutral network (SIANN) has been applied to eliminate the false-positive detections reported by a rule-based computer aided-diagnosis (CAD) scheme developed in our laboratory. Regions of interest (ROIs) were selected around the centers of the rule-based CAD detections and analyzed by the SIANN. In our previous study, background-trend correction and pixel-value normalization were used as the preprocessing of the ROIs prior to the SIANN. A ROI is classified as a positive ROI, if the total number of microcalcifications detected in the ROI is greater than a certain number. In this study, modifications were made to improve the performance of the SIANN. First, the preprocessing is removed because the result of the background-trend correction is affected by the size of ROIs. Second, image-feature analysis is employed to the output of the SIANN in an effort to eliminate some of the false detections by the SIANN. In order to train the SIANN to detect microcalcifications and also to extract image features of microcalcifications, the zero-mean-weight constraint and training-free-zone techniques have been developed. A cross-validation training method was also applied to avoid the overtraining problem. The performance of the SIANN was evaluated by means of ROC analysis using a database of 39 mammograms for training and 50 different mammograms for testing. The analysis yielded an average area under the ROC curve (A(z)) of 0.90 for the testing set. Approximately 62% of false-positive clusters detected by the rule-based scheme were eliminated without any loss of the true-positive clusters by using the improved SIANN with image feature analysis techniques.

Biophysical Phenomena↗
PubMed2005

Application of the Electrical Network Frequency (ENF) Criterion. A case of a digital recording.

One of the new methods of investigating the authenticity of evidential digital audio recordings uses the Electrical Network Frequency (ENF) Criterion. It is based on analysing the signal corresponding to the fundamental frequency of the current in the electrical network, which is present in a recording and comparing it with appropriate, reliable reference. Studies carried out at the Institute of Forensic Research in Cracow were aimed at validating this method, that is, assessing its usefulness in forensic examinations of evidential digital recordings in Poland. These studies enabled us to develop and implement a procedure for using the ENF Criterion method to assess the integrity of digital recordings and to establish when these recordings were made.

Journal Article↗
PubMedDate not supplied

A trial of cybernetic explanation of the development and regression of benign child epilepsy.

Using as an example the verification of a hypothetic mechanism of the course of benign child epilepsy the authors demonstrate a method of simulation investigations of neuron-like networks. The structure and possibilities of a digital system for network modelling are discussed, including the properties of the neuron-like element used presently for the experiments. The results of the simulation investigations described in the second part of the paper confirm the hypothesis that an attack of benign child epilepsy is a result of transgressing of the stability border by a fragment of the neuronal network with development in it of a self-exciting activity of a neuronal group.

Child↗