Optimal wavelength-space crossbar switches for supercomputer optical interconnects

We propose a most economical design of the Optical Shared MemOry Supercomputer Interconnect System (OSMOSIS) all-optical, wavelength-space crossbar switch fabric. It is shown, by analysis and simulation, that the total number of on-off gates required for the proposed N × N switch fabric can scale asymptotically as N ln N if the number of input/output ports N can be factored into a product of small primes. This is of the same order of magnitude as Shannon's lower bound for switch complexity, according to which the minimum number of two-state switches required for the construction of a N × N permutation switch is log2 (N!).

Assessment of radionuclide databases in CAP88 mainframe version 1.0 and Windows-based version 3.0

In this study the radionuclide databases for two versions of the Clean Air Act Assessment Package-1988 (CAP88) computer model were assessed in detail. CAP88 estimates radiation dose and the risk of health effects to human populations from radionuclide emissions to air. This program is used by several U.S. Department of Energy (DOE) facilities to comply with National Emission Standards for Hazardous Air Pollutants regulations. CAP88 Mainframe, referred to as version 1.0 on the U.S. Environmental Protection Agency Web site (http://www.epa.gov/radiation/assessment/CAP88/), was the very first CAP88 version released in 1988. Some DOE facilities including the Savannah River Site still employ this version (1.0) while others use the more user-friendly personal computer Windows-based version 3.0 released in December 2007. Version 1.0 uses the program RADRISK based on International Commission on Radiological Protection Publication 30 as its radionuclide database. Version 3.0 uses half-life, dose, and risk factor values based on Federal Guidance Report 13. Differences in these values could cause different results for the same input exposure data (same scenario), depending on which version of CAP88 is used. Consequently, the differences between the two versions are being assessed in detail at Savannah River National Laboratory. The version 1.0 and 3.0 database files contain 496 and 838 radionuclides, respectively, and though one would expect the newer version to include all the 496 radionuclides, 35 radionuclides are listed in version 1.0 that are not included in version 3.0. The majority of these has either extremely short or long half-lives or is no longer in production; however, some of the short-lived radionuclides might produce progeny of great interest at DOE sites. In addition, 122 radionuclides were found to have different half-lives in the two versions, with 21 over 3 percent different and 12 over 10 percent different.

A mainframe interfacing computer management system for the control of oral anticoagulant therapy

A unique computerized management system has been used to control the anticoagulation of over 400 patients at a large teaching hospital for the last eighteen months. The system is located on the main pathology computer which can be interfaced with the patient administration system (PAS). This enables files in the anticoagulant program to be linked with files in the PAS and files in the haematology database. This system has many advantages over a stand-alone microcomputer system and will form the basis for the next generation of computerized anticoagulant management systems.

Understanding implementation: the case of a computerized physician order entry system in a large Dutch university medical center

Most studies of the impact of information systems in organizations tend to see the implementation process as a "rollout" of technology, as a technical matter removed from organizational dynamics. There is substantial agreement that the success of implementing information systems is determined by organizational factors. However, it is less clear what these factors are. The authors propose to characterize the introduction of an information system as a process of mutual shaping. As a result, both the technology and the practice supported by the technology are transformed, and specific technical and social outcomes gradually emerge. The authors suggest that insights from social studies of science and technology can help to understand an implementation process. Focusing on three theoretical aspects, the authors argue first that the implementation process should be understood as a thoroughly social process in which both technology and practice are transformed. Second, following Orlikowski's concept of "emergent change," they suggest that implementing a system is, by its very nature, unpredictable. Third, they argue that success and failure are not dichotomous and static categories, but socially negotiated judgments. Using these insights, the authors have analyzed the implementation of a computerized physician order entry (CPOE) system in a large Dutch university medical center. During the course of this study, the full implementation of CPOE was halted, but the aborted implementation exposed issues on which the authors did not initially focus.

Computerized provider order entry systems

Computerized provider order entry (CPOE) systems are designed to replace a hospital's paper-based ordering system. They allow users to electronically write the full range of orders, maintain an online medication administration record, and review changes made to an order by successive personnel. They also offer safety alerts that are triggered when an unsafe order (such as for a duplicate drug therapy) is entered, as well as clinical decision support to guide caregivers to less expensive alternatives or to choices that better fit established hospital protocols. CPOE systems can, when correctly configured, markedly increase efficiency and improve patient safety and patient care. However, facilities need to recognize that currently available CPOE systems require a tremendous amount of time and effort to be spent in customization before their safety and clinical support features can be effectively implemented. What's more, even after they've been customized, the systems may still allow certain unsafe orders to be entered. Thus, CPOE systems are not currently a quick or easy remedy for medical errors. ECRI's Evaluation of CPOE systems--conducted in collaboration with the Institute for Safe Medication Practices (ISMP)--discusses these and other related issues. It also examines and compares CPOE systems from three suppliers: Eclipsys Corp., IDX Systems Corp., and Siemens Medical Solutions Health Services Corp. Our testing focuses primarily on the systems' interfacing capabilities, patient safeguards, and ease of use.

Using UNIX, Part 2

We talked about using 3 UNIX commands. In UNIX, there are many other options for using them. But for the most part, if you can use them like I have shown, you will be able to do everything you need. If you can learn these few points well, I think you will be better off than if I give you 50 options and leave you totally confused about when to do what. On some UNIX systems, an electronic version of the UNIX manual is on the system. This gives a lot more information about each command. However, it is a bit difficult to understand. If you want more information about any command, you can type man COMMAND, e.g., man ls. This will give you more ways to use the ls command. And remember, the command pwd tells what directory you are in, cd/directory changes to another directory, ls lists the contents of the directory you are in, ls more displays the directory contents 1 page at a time (the space bar gives you the next page), ls-al gives a detailed listing of the contents of the directory you are in, ls-al more displays them 1 page at a time (the space bar gives you the next page).

The role of clinical engineers in hospitals: essential or expedient?

This article explores the capabilities of those technicians and clinical engineers who manage biomedical equipment. Equipment technicians maintain the equipment in hospitals and may participate in some basic equipment management. Clinical engineers, on the other hand, may augment this management effort in equipment-intensive hospitals by designing the specifications and procedures needed to integrate equipments into properly working systems and to maintain them under local conditions. In addition, clinical engineers can improve equipment management by providing an engineering viewpoint to such areas as technology assessment, computer applications, quality improvement, and in-service education.

Information resources assessment of a healthcare integrated delivery system

While clinical healthcare systems may have lagged behind computer applications in other fields in the shift from mainframes to client-server architectures, the rapid deployment of newer applications is closing that gap. Organizations considering the transition to client-server must identify and position themselves to provide the resources necessary to implement and support the infrastructure requirements of client-server architectures and to manage the accelerated complexity at the desktop, including hardware and software deployment, training, and maintenance needs. This paper describes an information resources assessment of the recently aligned Pennsylvania regional Veterans Administration Stars and Stripes Health Network (VISN4), in anticipation of the shift from a predominantly mainframe to a client-server information systems architecture in its well-established VistA clinical information system. The multimethod assessment study is described here to demonstrate this approach and its value to regional healthcare networks undergoing organizational integration and/or significant information technology transformations.

Racing toward client-server solutions

If mainframe computing is like driving a reliable sedan, some experts say client-server computing is like driving a fast, maneuverable sports car. But until you understand and fine-tune a client-server system, performance can be disappointing.

Remote quantitation server for quality assurance in DNA ploidy analysis

OBJECTIVE

To remotely test a stepwise framework of quality control measures, developed according to the 1997 European Society of Analytical Cellular Pathology consensus on diagnostic DNA image cytometry, in two series of measurements by means of the quantitation server EUROQUANT.

STUDY DESIGN

In each of these series, 104 fine needle aspiration biopsies, imprints from breast cancer specimens and 28 rat liver imprints were measured twice at two different cytometry workstations. Further measurements on special rat liver specimens for evaluation of the stability of the machinery and of the preparation process were done at both workstations. Afterwards the measurement data from both machines were transferred to the quantitation server and analyzed automatically. Beside the classical DNA histograms, a set of further evaluations was performed to detect optical errors as well as inhomogeneities in the measurements. Running values for mean integrated optical density values, mean corrective factors and mean coefficients of variations of corrective factors were computed to control the stability of the entire methodology over time.

RESULTS

The study demonstrated the preconditions and outcome of server-based quality control in DNA ploidy analysis. The results show that such a remote analysis is feasible and comparable to local DNA ploidy analysis. It is also demonstrated how quality control tests reflect the process performance of ploidy analysis at its different levels.

CONCLUSION

Quality control must be an inherent part of the daily routine to allow a reliable diagnostic interpretation and ensure steadily high product quality.

Connectivity and control in the year 2000 and beyond

By now, most executives are familiar with the famous Year 2000 problem--and many believe that their companies have the situation well in hand. After all, it seems to be such a trivial problem--computer software that interprets "oo" to be the year 1900 instead of the year 2000. And yet armies of computer professionals have been working on it--updating code in payroll systems, distribution systems, actuarial systems, sales-tracking systems, and the like. The problem is pervasive. Not only is it in your systems, it's in your suppliers' systems, your bankers' systems, and your customers' systems. It's embedded in chips that control elevators, automated teller machines, process-control equipment, and power grids. Already, a dried-food manufacturer destroyed millions of dollars of perfectly good product when a computer counted inventory marked with an expiration date of "oo" as nearly a hundred years old. And when managers of a sewage-control plant turned the clock to January I, 2000 on a computer system they thought had been fixed, raw sewage pumped directly into the harbor. It has become apparent that there will not be enough time to find and fix all of the problems by January I, 2000. And what good will it do if your computers work but they're connected with systems that don't? That is one of the questions Harvard Business School professor Richard Nolan asks in his introduction to HBR's Perspectives on the Year 2000 issue. How will you prepare your organization to respond when things start to go wrong? Fourteen commentators offer their ideas on how senior managers should think about connectivity and control in the year 2000 and beyond.

Renewing information infrastructure at Hospital das Clínicas

In this paper we describe the process of renewing the Informatics infrastructure of Sao Paulo University Medical School Hospital, a very complex environment. Our proposal consists of a change in the paradigm of Informatics and the use of Information Technology in the hospital. That change aims at making information available to the hospital, its managers, health care workers and patients. The paradigm change is reflected in every aspect of the new infrastructure: human resources, methods, and organizational structure, as we intend to demonstrate in this paper. This process is expected to be concluded by the end of this year, yielding benefits regarding costs, efficiency, and better patient care.

Married to the mainframe

Despite the growth of client/server technologies, many healthcare organizations remain committed to their mainframe systems. But will mainframes remain good partners for years to come?

With costs and demands for expertise rising, health care is increasingly putting computer systems on ... remote control

Outside managers already have a grip on running the information systems that power and support health care. It's their largest market--and it's just getting started. Investment analysts see a boom in the making, fueled by accelerating costs and demands for expertise.

Information systems. T-minus 34 months and counting. The year 2000 has ominous implications for computer systems

The countdown has started to the year 2000, which has ominous implications for computer systems. Healthcare executives are discovering that changes in their industry further complicate solving the "century date" problem. Meanwhile, a survey of healthcare executives shows they are refocusing on the nuts and bolts of information technology and reining in their ambition to have it all at once.

Integrating pharmacokinetics into point-of-care information systems

Computer-based patient care information systems (PCIS) have emerged as an integral component of healthcare organisations. Currently, 4 models of PCIS exist: the centralised model, the hub-and-spoke model, the network model, and the distributed model. The centralised model has the advantage of a central patient database; however, a major disadvantage of this model is the inability to easily interface with other software packages. The hub-and-spoke model links satellite or feeder systems into a mainframe computer; thus, each satellite has the ability to work independently. This system is limited by the ability to interface satellite systems with the mainframe computer. The network model works via a local area network (LAN) using client server technology which allows for high speed data access and transfer. The network model does not provide an integrated view of patient information and can access only 1 host system at a time. The distributed model is similar to the network model in design but provides for data and system integration via relational databases. This allows for the creation of a central data repository and support for decision-support tools. Computer-assisted decision support has the potential to significantly improve clinical decision-making. Six types of computer-assisted decision-support have been defined: alerting, interpreting, assisting, critiquing, diagnosing and managing. Software representing each type of decision-support software has been incorporated into clinical practice; however, with the exception of drug interaction programs, widespread incorporation of decision-support software into PCIS is uncommon. Clinical pharmacokinetic programs are a category of pharmacy-related decision-support software, and current clinical pharmacokinetic software systems can be categorised as interpreting, assisting or critiquing decision-support. Despite the potential for significant clinical contributions, the integration of clinical pharmacokinetic software into PCIS is uncommon. Most packages are available only as stand alone programs or as a module of a pharmacy information system. These packages usually maintain their own centralised database and require special file transfer protocols for integration. Although PCIS are becoming more commonplace, the integration of commercial clinical pharmacokinetic packages into PCIS is limited. New technology using standardised and relational databases should allow for easier integration in the future.

A new approach to the implementation of direct care-provider order entry

Successful implementation of direct computer-based care-provider order entry traditionally relies on one of two different approaches development from scratch or installation of a commercial product. The former requires extensive resources; the latter, by its proprietary nature, limits extension of the system beyond capabilities supplied by the vendor. This paper describes an intermediate approach using the association of a locally-developed and controlled set of distributed microcomputer based applications and a commercial, mainframe-based order entry application used as an order transaction processing system. This combination provides both an intuitive user interface and a platform for implementing clinical decision-support tools.

Evolution of a legacy system to a Web patient record server: leveraging investment while opening the system

A layered system is under development to enhance our legacy system as a backend in a WEB-enabled system. Each layer of the system has defined functionality, leverages the investment in the layer below, and follows the strategy of reducing support requirements for workstations. The mainframe system provides administrative integration of sub-systems, security, and the central data repository for most information. The second layer is a graphical user interface (GUI) to the system for Windows platforms. Support needs are limited by relying chiefly on X-terminals and application servers. The "Intranet" layer is a WEB Server building upon the second layer gateways to provide platform-independent access to selected information and images. The fourth layer, under evaluation, will extend access to the central data repository for Internet users of web browsers that support private-key/public-key encryption.

Medical image processing utilizing neural networks trained on a massively parallel computer

While finding many applications in science, engineering, and medicine, artificial neural networks (ANNs) have typically been limited to small architectures. In this paper, we demonstrate how very large architecture neural networks can be trained for medical image processing utilizing a massively parallel, single-instruction multiple data (SIMD) computer. The two- to three-orders of magnitude improvement in processing time attainable using a parallel computer makes it practical to train very large architecture ANNs. As an example we have trained several ANNs to demonstrate the tomographic reconstruction of 64 x 64 single photon emission computed tomography (SPECT) images from 64 planar views of the images. The potential for these large architecture ANNs lies in the fact that once the neural network is properly trained on the parallel computer the corresponding interconnection weight file can be loaded on a serial computer. Subsequently, relatively fast processing of all novel images can be performed on a PC or workstation.

Application of high-performance computing to numerical simulation of human movement

We have examined the feasibility of using massively-parallel and vector-processing supercomputers to solve large-scale optimization problems for human movement. Specifically, we compared the computational expense of determining the optimal controls for the single support phase of gait using a conventional serial machine (SGI Iris 4D25), a MIMD parallel machine (Intel iPSC/860), and a parallel-vector-processing machine (Cray Y-MP 8/864). With the human body modeled as a 14 degree-of-freedom linkage actuated by 46 musculotendinous units, computation of the optimal controls for gait could take up to 3 months of CPU time on the Iris. Both the Cray and the Intel are able to reduce this time to practical levels. The optimal solution for gait can be found with about 77 hours of CPU on the Cray and with about 88 hours of CPU on the Intel. Although the overall speeds of the Cray and the Intel were found to be similar, the unique capabilities of each machine are better suited to different portions of the computational algorithm used. The Intel was best suited to computing the derivatives of the performance criterion and the constraints whereas the Cray was best suited to parameter optimization of the controls. These results suggest that the ideal computer architecture for solving very large-scale optimal control problems is a hybrid system in which a vector-processing machine is integrated into the communication network of a MIMD parallel machine.

A semiautomated image analysis procedure for the quantification of dental microwear II

Paleontologists often examine microscopic scratches and pits that form on teeth for indications of the diets of past animals. Most researchers count and measure scratches and pits from photomicrographs to identify microwear patterns for comparison among samples. This paper describes an affordable, available semiautomated image analysis procedure for microwear quantification. An image is downloaded from a scanning electron microscope frame buffer to a microcomputer, and the user identifies microwear features with a mouse-driven pointer. Microwear feature density, dimensions, and orientations are then computed and stored as ASCII files for subsequent data analysis.

Stereotactic gamma-thalamotomy with a computerized brain atlas: technical case report

Radiosurgical stereotactic thalamotomy was performed in a patient with parkinsonian tremor with a computerized stereotactic brain atlas, which was transformed to fit the patient's thin-sliced magnetic resonance image to select an optimal target in the nucleus ventralis intermedius of the thalamus. The patient's tremor and rigidity disappeared and have not appeared again for more than 1 year since the eighth postoperative month. A method for converting the presurgically planned stereotactic coordinates in the atlas coordinate system to the coordinates in the frame coordinate system is described.

One size doesn't fit all

As a company changes in scope and character, so must its information systems. Here is a case of a multitude of risks and gains by a large hospital supplier that was spun off from its parent and decided to convert from the world of a large mainframe computer to networked personal computers.

Annual managed care systems review. Behold the beast

Remember the story of the three blind men, each confronted by a different part of an elephant? Asked to describe the object in front of them, they each described the part they could touch. In his quest to survey more than 100 managed care systems vendors, author John R. Murray discovered that defining managed care is very much like describing an elephant without seeing the entire beast: Each company's definition is based on its niche and product offering to the market.