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Computer aided design, interactive software, man-machine interaction, software prototyping, modeling, Electronic computers. Computer science, and QA75.5-76.95

Computer aided design (CAD) systems, or more generally interactive software, are today being developed for various application areas like VLSI-design, mechanical structure design, avionics design, cartographic design, architectual design, office automation, publishing, etc. Such tools are becoming more and more important in order to be productive and to be able to design quality products. One important part of CAD-software development is the man-machine interface (MMI) design.

Humans, Pedigree, Data Collection, Database Management Systems, Genetic Diseases, Inborn, and Software

This work examines some of the problems encountered in developing small and large database application systems involving human genetics data collection efforts that include data on individuals as well as family pedigree data. Rapid prototyping of a database application requires software tools to produce the application with little or no programming. Features of MEGADATS-4 that provide for rapid prototyping and for producing stand-alone applications are examined.

Database Management Systems, Medical Informatics Applications, Programming Languages, Software Design, Information Systems, and Software

AIDA consists of a set of software tools to allow for fast development and easy-to-maintain Medical Information Systems. AIDA supports all aspects of such a system both during development and operation. It contains tools to build and maintain forms for interactive data entry and on-line input validation, a database management system including a data dictionary and a set of run-time routines for database access, and routines for querying the database and output formatting. Unlike an application generator, the user of AIDA may select parts of the tools to fulfill his needs and program other subsystems not developed with AIDA. The AIDA software uses as host language the ANSI-standard programming language MUMPS, an interpreted language embedded in an integrated database and programming environment. This greatly facilitates the portability of AIDA applications. The database facilities supported by AIDA are based on a relational data model. This data model is built on top of the MUMPS database, the so-called global structure. This relational model overcomes the restrictions of the global structure regarding string length. The global structure is especially powerful for sorting purposes. Using MUMPS as a host language allows the user an easy interface between user-defined data validation checks or other user-defined code and the AIDA tools. AIDA has been designed primarily for prototyping and for the construction of Medical Information Systems in a research environment which requires a flexible approach. The prototyping facility of AIDA operates terminal independent and is even to a great extent multi-lingual. Most of these features are table-driven; this allows on-line changes in the use of terminal type and language, but also causes overhead. AIDA has a set of optimizing tools by which it is possible to build a faster, but (of course) less flexible code from these table definitions. By separating the AIDA software in a source and a run-time version, one is able to write implementation-specific code which can be selected and loaded by a special source loader, being part of the AIDA software. This feature is also accessible for maintaining software on different sites and on different installations.

Drug Information Services, Netherlands, Hospital Information Systems, Pharmacy Service, Hospital, and Software

The CENTRASYS system for the Hospital Pharmacy, developed as part of a research project of the Department of Medical Informatics is described. The role of AIDA, a fourth-generation software package, as a prototyping tool is discussed. It is concluded that AIDA facilitates prototyping and is also very suitable as a vehicle for systems in operation. It is further concluded that prototyping is of great help in the developmental phase of a project, but that great care has to be taken during evaluation of the prototypes: minimize the number of test sites and try to avoid that users become dependent on the system, because every prototype needs further tuning before it really becomes an operational system.

Evaluation Studies as Topic, Hospital Information Systems, Pharmacy Service, Hospital, Primary Health Care, Software Design, and Software

A system for hospital pharmacies (CENTRASYS) and a system for primary health care (ELIAS), both developed using prototyping and a fourth-generation tool (AIDA), are introduced. Differences in development strategies are analyzed and conclusions are drawn with respect to the use of AIDA for management, development and operation of the systems. The use of AIDA increases development speed enormously, enabling a productivity of over 40 lines per day, which is more than twice the amount that is accepted as reasonable.

Animals, Cricetinae, Netherlands, Pilot Projects, Software Design, User-Computer Interface, Information Systems, Primary Health Care, and Software

In this article the development of a computer system for General Practice, ELIAS, is described. The use of the 4th-generation software toolkit AIDA proved to be very helpful in increasing the speed of development as well as the quality of the ELIAS software. The programming support that AIDA offered, not only in increasing the rate of development but also in the flexible way in which parts of the system and the database can be adjusted (in prototyping as well as in the operational system) and its self-documenting functions, contributed to the ease of development. The consistent lay-out of the frames and uniform screen-handling, the opportunity of data validation and the availability of help information at every item in screen frames--all facilitated by AIDA--rendered ELIAS a very user-friendly system.

Man-machine systems, human factors, underseas systems, prototyping, system analysis, guidance systems, Electronic computers. Computer science, and QA75.5-76.95

Important man-machine interface (MMI) issues concerning a submarine command and weapon control system (CWCS) such as crew organization, automation level and decision support are discussed in this paper. Generic submarine CWCS functions and operating conditions are outlined. Detailed, dynamic and real-time prototypes were used to support the MMI design. The prototypes are described and experience with detailed prototyping is discussed. Some of the main interaction principles are summarized and a restricted example of the resulting design is given. Our design experience and current work have been used to outline future perspectives of MMI design in naval CWCSs. The need for both formal and experimental approaches is emphasized.

Blood Glucose Self-Monitoring, Diabetes Mellitus blood, Diabetes Mellitus physiopathology, Diet, Diabetic, Exercise, Humans, Insulin physiology, Microcomputers, Numerical Analysis, Computer-Assisted, Prognosis, Blood Glucose metabolism, Diabetes Mellitus drug therapy, Expert Systems, Insulin administration dosage, and Therapy, Computer-Assisted

This paper describes the principles and prototyping of a computer-based system being developed to assist in the management of diabetes mellitus. Unlike other approaches based upon mathematical modelling or the use of computer algorithms, this system adopts one derived from artificial intelligence, seeking to incorporate the dynamics of glucose and insulin in a manner which reflects their clinical importance. The resultant logical model (qualitative algebra) defines the relationships between changes in insulin dose and site and time of injection and glycaemic response. In this manner the computer-based system, implemented in Prolog, can be used to provide advice concerning insulin therapy by means of making qualitative predictions of patient outcome of blood glucose profile resulting from alternative insulin regimens.

Adult, Decision Making, Computer-Assisted, Humans, Pulmonary Gas Exchange, Signal Processing, Computer-Assisted, Carbon Dioxide blood, Expert Systems, Respiratory Insufficiency therapy, Software, and Ventilators, Mechanical

The KUSIVAR is an expert system for mechanical ventilation of adult patients suffering from respiratory insufficiency. Its main objective is to provide guidance in respirator management. The knowledge base includes both qualitative, rule-based knowledge and quantitative knowledge expressed in the form of mathematical models (expert control) which is used for prediction of arterial gas tensions and optimization purposes. The system is data driven and uses a forward chaining mechanism for rule invocation. The interaction with the user will be performed in advisory, critiquing, semi-automatic and automatic modes. The system is at present in an advanced prototype stage. Prototyping is performed using KEE (Knowledge Engineering Environment) on a Sperry Explorer workstation. For further development and clinical use the expert system will be downloaded to an advanced PC. The system is intended to support therapy with a Siemens-Elema Servoventilator 900 C.

Efficiency, Models, Theoretical, Planning Techniques, United States, and Hospital Information Systems

One way automation can increase efficiency is through rapid prototyping, particularly of user interfaces. AI and logic programming, argues this author, offer good user interface tools and a suitable prototyping environment.

Magnetic Resonance Imaging, Tomography, Emission-Computed, Tomography, X-Ray Computed, Ultrasonography, Image Processing, Computer-Assisted methods, Software, Software Design, and User-Computer Interface

A comprehensive software package, called ANALYZE, has been developed (1) which permits detailed investigation and evaluation of multidimensional biomedical images. ANALYZE can be used with 3-D imaging modalities based on x-ray computed tomography, radionuclide emission tomography, ultrasound tomography, and magnetic resonance imaging. The software is written entirely in "C" and runs on standard UNIX workstations. The ANALYZE package features integrated, complimentary tools for fully interactive display, manipulation and measurement of multidimensional image data. The software architecture permits systematic enhancements and upgrades which has fostered development of a readily expandable package. It provides an effective shell for custom software prototyping and turnkey applications. This paper provides a general description of this software as well as specific details on the methodology employed to develop it, both conceptual and technical. Applications of the software are illustrated.

Amino Acid Sequence, Chemical Phenomena, Chemistry, Protein Conformation, Information Systems, and Proteins

An object-oriented database system has been developed which is being used to store protein structure data. The database can be queried using the logic programming language Prolog or the query language Daplex. Queries retrieve information by navigating through a network of objects which represent the primary, secondary and tertiary structures of proteins. Routines written in both Prolog and Daplex can integrate complex calculations with the retrieval of data from the database, and can also be stored in the database for sharing among users. Thus object-oriented databases are better suited to prototyping applications and answering complex queries about protein structure than relational databases. This system has been used to find loops of varying length and anchor positions when modelling homologous protein structures.

The aim of this study was to evaluate and improve the menu interface design of an existing expert system. The system provided expertise concerned with evaluating human response to environments and was implemented onto a computer with a simple tree menu system. Two laboratory based experiments were carried out in which alternative menu interface designs were developed rapidly and compared with the original design. User acceptance tests which incorporated objective and subjective measures were iteratively used to evaluate and improve the interface designs. The results of these experiments indicated that, for the particular system under study, a graphic based design which displayed 58 options divided into levels on a single screen was preferred by users over the original menu interface which displayed one menu at a time with seven options per screen. The final interface remains to be tested under field conditions.

Hospital Information Systems, Microcomputers, North Carolina, Software, Computer Communication Networks, Information Systems, Medical Records Systems, Computerized, and User-Computer Interface

Many hospitals today have implemented widely disparate information systems on mainframe and mini-computer hardware. The advent of network technology in hospitals has made it possible to access information in these systems. Unfortunately, the user interfaces to applications on these system are unique and difficult to learn, which makes them unsuitable for use by clinical services. In this paper we describe the development using rapid prototyping object-oriented programming tools of a Physician's Workstation which integrates information from five different applications running on three separate computer systems.

Clinical Laboratory Information Systems, Critical Care, Decision Making, Computer-Assisted, Denmark, Diagnosis, Computer-Assisted, Expert Systems, Finland, Microcomputers, Monitoring, Physiologic, Sweden, Therapy, Computer-Assisted, User-Computer Interface, and Artificial Intelligence

A Nordic research and development programme, 'KBS in Medicine' (KUSIN-MEDICINE), was run in 1986-89. Its main goal was to acquire an understanding of applying knowledge-based techniques in medicine and of the limitations of present-day artificial intelligence (AI) methodologies. The programme comprised four experimental installation sites (Tampere in Finland, Uppsala and Linköping in Sweden, and Aalborg in Denmark) each prototyping in one or more medical domains. The programme was financed by the Nordic Fund for Technological and Industrial Development, by national funds for applied research and by a number of industries. Prototype decision support systems were produced in the following domains: intensive care (Tampere, Uppsala, Linköping, Aalborg), clinical chemistry (Tampere, Uppsala) and clinical neurophysiology (Aalborg in collaboration with Turku and Uppsala). These served to transfer this technology to industry and helped to identify limitations of this technology.

Computer Graphics, Programming Languages, Hospital Information Systems, Medical Records Systems, Computerized, and User-Computer Interface

The PRIST-2 system has been designed as an interactive and high-productivity tool for the rapid prototyping and development of medical applications. Three major issues were addressed in this research project which derived from the evolution of a previous 4th generation software package, called PRIST (patient record information system tool): a high transportability on different hardware and operating systems, a conversational and interactive user-interface and user-independence Relational Data Base Management System (RDBMS). Although we developed PRIST-2 on the top of the ORACLE RDBMS, it does not depend on SQL commercial products because the ORACLE features have been directly used only for SQL relational data base management. The application design methodology implemented in the system architecture allows an interactive and formal description of the application constraints in terms of the semantic data model rather than in terms of the data structure. The translation of the conceptual constraints into SQL tables is performed by several pre-defined routines. In the PC based release (MS/DOS, OS/2, Xenix operating systems), the Graphic-User Interface (GUI) has been developed using Microsoft Windows Software Development Kit. The UNIX release will use a GUI developed on top of the X-Windows environment.

Adult, Breast Neoplasms pathology, Carcinoma pathology, Computer Systems, Decision Theory, Decision Trees, Diagnosis, Computer-Assisted, Expert Systems, Female, Humans, Programming Languages, Decision Support Techniques, Medical Informatics, and Software Design

The concept of object-oriented design and programming has recently received a great deal of attention from the software engineering community. This paper highlights the realisable benefits of using the object-oriented approach in the design and development of clinical decision support systems. These systems seek to build a computational model of some problem domain and therefore tend to be exploratory in nature. Conventional procedural design techniques do not support either the process of model building or rapid prototyping. The central concepts of the object-oriented paradigm are introduced, namely encapsulation, inheritance and polymorphism, and their use illustrated in a case study, taken from the domain of breast histopathology. In particular, the dual roles of inheritance in object-oriented programming are examined, i.e., inheritance as a conceptual modelling tool and inheritance as a code reuse mechanism. It is argued that the use of the former is not entirely intuitive and may be difficult to incorporate into the design process. However, inheritance as a means of optimising code reuse offers substantial technical benefits.

Drug Prescriptions, Medical Records Systems, Computerized, Nursing, Ambulatory Care, Artificial Intelligence, and Practice Guidelines as Topic

As we understand the process of ambulatory care better, the need to effectively implement standards of practice becomes more apparent. To facilitate successful use of practice guidelines, we have integrated an artificial intelligence system of Medical Logic Modules into our computerized medical record. A rule shell allows rapid development and prototyping of rules which can be practice reminders, information gathering utilities, or standing orders. A set of utilities allows non-programmer clinicians to develop and maintain the rule set. We will demonstrate these enhancements in the context of the comprehensive patient record.

Cost-Benefit Analysis, Decision Making, Organizational, Decision Support Techniques, Models, Structural, Planning Techniques, Product Line Management economics, Professional Staff Committees economics, Professional Staff Committees organization administration, United States, Industry organization administration, and Product Line Management methods

Extended development cycles put companies at risk through loss of sales, margins, market share, and credibility as innovators. The author suggests constructing early-stage models to provide a dress rehearsal for new products and help companies develop products in less time.

Rapid prototyping or 'virtual prototyping' of human-machine interfaces offers the possibility of putting the human operator 'in the loop' without the effort and cost associated with conventional man-in-the-loop simulation. Advocates suggest that rapid prototyping is compatible with conventional systems development techniques. It is not clear, however, exactly how rapid prototyping could be used in relation to conventional human factors engineering analyses. Therefore, an investigation of the use of the VAPS virtual prototyping system was carried out in five organizations. The results show that a variety of task analysis approaches can be used to initiate rapid prototyping. Overall, it appears that rapid prototyping facilitates an iterative approach to the development of the human-machine interface, and that is most applicable to the early stages of systems development, rather than to detailed design.

Computer Communication Networks, Computer Systems, Databases, Bibliographic, Databases, Factual, Information Storage and Retrieval, National Library of Medicine (U.S.), United States, Academic Medical Centers, Integrated Advanced Information Management Systems, and Unified Medical Language System

The paper describes a prototype information environment designed to link network-based information resources in an integrated fashion and thus enhance the information capabilities of an academic medical center. The prototype was implemented on a single Macintosh computer to permit exploration of the overall "information architecture" and to demonstrate the various desired capabilities prior to full-scale network-based implementation. At the heart of the prototype are two components: a diverse set of information resources available over an institutional computer network and an information sources map designed to assist users in finding and accessing information resources relevant to their needs. The paper describes these and other components of the prototype and presents a scenario illustrating its use. The prototype illustrates the link between the goals of two National Library of Medicine initiatives, the Integrated Academic Information Management System (IAIMS) and the Unified Medical Language System (UMLS).

Clinical Protocols, Semantics, Database Management Systems organization administration, Hospital Information Systems organization administration, Software Design, and User-Computer Interface

A 4th generation tool, called PRIST-2, is presented that has been designed as an interactive environment for the rapid prototyping of clinical applications in a large-scale Hospital Information System project. We adopted an SQL-based commercial Relational Data Base Management Systems (RDBMS) to guarantee portability on different hardware and operating systems. Relational databases, however, are characterized by a simple data structure and do not incorporate the application semantics required to ensure a high degree of data independence. To reach this goal, we propose an extension to the relational model, adding some of the main characteristics of the Object Oriented Data Base Management Systems (OODBMS) approach, such as "types" and "encapsulation".

Computer Literacy, Humans, Mid-Atlantic Region, Organizational Culture, Organizational Innovation, User-Computer Interface, Ambulatory Care Information Systems statistics numerical data, Attitude to Computers, Managed Care Programs, and Physicians psychology

Kaiser Permanente Mid-Atlantic States has developed a fully integrated outpatient information system which currently runs on an IBM ES9000 on a VM platform written in MUMPS. The applications include Lab, Radiology, Transcription, Appointments. Pharmacy, Encounter tracking, Hospitalizations, Referrals, Phone Advice, Pap tracking, Problem list, Immunization tracking, and Patient demographics. They are department specific and require input and output from a dumb terminal. We have developed a physician's work station to access this information using PC compatible computers running Microsoft Windows and a custom Microsoft Visual Basic 2.0 environment which draws from these 14 applications giving the physician a comprehensive view of all electronic medical records. Through rapid prototyping, voluntary participation, formal training and gradual implementation we have created an enthusiastic response. 95% of our physician PC users access the system each month. The use ranges from 0.2 to 3.0 screens of data viewed per patient visit. This response continues to drive the process toward still greater user acceptance and further practice enhancement.

Computer Systems, Humans, Physicians, Hospital Information Systems statistics numerical data, Medical Records Systems, Computerized statistics numerical data, and Software Design

The M.D. Rounds Report program was developed and implemented in June of 1992 as an adjunct to the HELP System at Rex Hospital. The program facilitates rapid access to information on allergies and current medications, laboratory results, radiology reports and therapist notes for a list of patients without physicians having to make additional menu or submenu selections. In planning for an upgrade of the program, utilization statistics and user feedback provided valuable information in terms of frequency of access, features used and unused, and the value of the program as a reporting tool in comparison to other online results reporting applications. A brief description of the functionality of the M.D. Rounds Report, evaluation of the program audit trail and user feedback, planned enhancements to the program, and a discussion of the prototyping and monitoring experience and the impact on future physician subsystem development will be presented.

Humans, Medical Records Systems, Computerized, Microcomputers, Ambulatory Care Information Systems, Family Practice, and User-Computer Interface

ISAAC (Integrated System Architecture for Advanced Primary Care) is a project aiming at developing information technology and telematic support in the specific field of General Practice--and more broadly in the Primary Health Care sector--within the health care systems of different European Countries. The project aims at improving the work of the General Practitioners through the development of a useful and usable medical workstation for day-to-day patient care. Moreover ISAAC has the goal of prototyping an integration architecture for the improvement of the communications between the ISAAC workstation and heterogeneous application environments, namely other components of the health care system. This paper deals with a general description of the design along with a discussion of the adopted approach to fulfill the integration requirements.

Clinical Protocols, Data Display, Database Management Systems, Databases, Factual, Humans, Medical Oncology, Software Design, Computer Graphics, Expert Systems, Neoplasms therapy, and User-Computer Interface

We describe a graphic user interface for an expert system in oncology. The main objectives of our work has been to facilitate the adaptation of the system to different clinical environments and potentiate the factors which more directly determine the acceptance of the system by its users. We present the design principles derived from the features of the clinical domain chosen and from the objectives of the system. These principles are reflected on the design of the screen and of the interaction and in the style of integration of the interface with the other components of the system. Underlying the application we describe is a graphic user interface management system which provides facilities for the fast prototyping and integration of interfaces. We describe here those features of this tool which make the practical application of the design principles we consider possible.

Humans, Patient Care Team, Program Evaluation, Computer Systems, Documentation, and Hospital Information Systems

The implementation of a comprehensive bedside documentation system is a major project that demands careful analysis and planning. Since the cost of a typical bedside system can easily exceed $3 million, a design oversight could have disastrous effects on the benefits of the system.

Computer Graphics and Clinical Laboratory Information Systems

The computing strategy in our laboratories evolved from research in Artificial Intelligence, and is based on powerful software tools running on high performance desktop computers with a graphical user interface. This allows most tasks to be regarded as design problems rather than implementation projects, and both rapid prototyping and an object-oriented approach to be employed during the in-house development and enhancement of the laboratory information systems. The practical application of this strategy is discussed, with particular reference to the system designer, the laboratory user and the laboratory customer. Routine operation covers five departments, and the systems are stable, flexible and well accepted by the users. Client-server computing, currently undergoing final trials, is seen as the key to further development, and this approach to Pathology computing has considerable potential for the future.

Chemistry, Clinical, Critical Care, Humans, and Clinical Laboratory Information Systems

Interoperability may be defined as the ability of knowledge-based systems to function together in a symbiotic manner. Cooperativity implies interoperability but with the added benefit that the output quality of the cooperative network exceeds the overall performance of the participating sub-systems. A number of candidate architectures to support interoperability and cooperativity between medical knowledge-based systems in laboratory medicine domains are now becoming available. Using rapid prototyping techniques, we have demonstrated the feasibility of one of these approaches by carrying out pilot implementations in two unrelated laboratory medicine domains (an internal consistency checking system for validating patients' results in the laboratory and a system for generating alarms and alerts in high dependency units based on laboratory data). The results of this study are discussed in the context of the available techniques so as to provide a basis for further development of cooperative systems in laboratory medicine.

Computer Systems, Software, and Systems Integration

Computer scientists working in medical informatics have to face the problem that software offered by industry is more and more adopted for clinical use by medical professionals. A new challenge arises of how to combine commercial solutions with typical medical software that already exists for some years and proved to be reliable with these off-the-shelf solutions [1]. With the HERMES project, this new challenge was accepted and possible solutions to integrate existing legacy systems with state-of-the-art commercial solutions have been investigated. After a period of prototyping to assess possible alternative solutions, a system based on an indirect client-server model was implemented with help of the industry. In this paper, its architecture is described together with the most important features currently covered. Based on the HERMES architecture, both systems for clinical data analysis and patient care (cardiology) are currently developed.

Ambulatory Care Information Systems, Computer Communication Networks, and Computer Systems

PWS is a physician's workstation research prototype developed to explore the use of information management tools by physicians in the context of patient care. The original prototype was implemented in a client/server architecture using a broadcast message server. As we expanded the scope of the prototyping activities, we identified the limitations of the broadcast message server in the areas of scalability, security, and interoperability. To address these issues, we reimplemented PWS using the Open Software Foundation's Distributed Computing Environment (DCE). We describe the rationale for using DCE, the migration process, and the benefits achieved. Future work and recommendations are discussed.

Artificial Intelligence, Computer Communication Networks, Database Management Systems, Delivery of Health Care, Humans, Information Storage and Retrieval, Software Design, User-Computer Interface, Computer Systems, Integrated Advanced Information Management Systems, and Software

The development of medical workstations for the support of patient care, the assessment of care, management support, and education is just at its beginning. During the Working Conference on the Health care Professional Workstation held in Washington DC, June 1993, several aspects of such workstations were discussed, but it was also recognized that prototyping or learning by experience could be a rich source to further promote the progress in this field. Eight such prototypes or already operational medical workstations were demonstrated and a preliminary user assessment was done to obtain a first insight in the advantages and the type of criteria of such evaluations. It was concluded that such assessments were of great value to (i) give feedback to the designers of medical workstations, (ii) indicate areas of strength and for further research, and (iii) to offer criteria to potential users of such workstations for making decisions on using such systems. The assessment criteria deal with functionality, architecture, user interfaces, communications and integration, and data and knowledge management.

Humans, Skull anatomy histology, Image Processing, Computer-Assisted, Skull diagnostic imaging, and Tomography, X-Ray Computed

A study was undertaken to determine the dimensional accuracy of anatomical replicas derived from X-ray 3D computed tomography (CT) images and produced using the rapid prototyping technique of stereolithography (SLA). A dry bone skull and geometric phantom were scanned, and replicas were produced. Distance measurements were obtained to compare the original objects and the resulting replicas. Repeated measurements between anatomical landmarks were used for comparison of the original skull and replica. Results for the geometric phantom demonstrate a mean difference of +0.47 mm, representing an accuracy of 97.7-99.12%. Measurements of the skull produced a range of absolute differences (maximum +4.62 mm, minimum +0.1 mm, mean +0.85 mm). These results support the use of SLA models of human anatomical structures in such areas as pre-operative planning of complex surgical procedures. For applications where higher accuracy is required, improvements can be expected by utilizing smaller pixel resolution in the CT images. Stereolithographic models can now be confidently employed as accurate, three-dimensional replicas of complex, anatomical structures.

Decision Support Techniques, Expert Systems, Systems Integration, Artificial Intelligence, Clinical Laboratory Information Systems, Decision Making, Computer-Assisted, Programming Languages, and Reminder Systems

This article reviews the efforts of HBO & Company in the production of a first phase clinical alerting system based on the Arden Syntax. The alerting system was integrated with a clinical data repository and clinical workstation to process returning laboratory results. Investigations with expert systems resulted in a C language alerting system. GUI prototyping of an authoring environment led to a Smalltalk language authoring system. Future development is expected to broaden the system scope and address the evolution of the Arden Syntax.

Computer Security, General Surgery, Humans, Information Systems, User-Computer Interface, Computer Communication Networks, Computer Systems, Data Display, and Medical Records Systems, Computerized

We have experimented with developing a prototype Surgeon's Workstation which makes use of the World Wide Web client-server architecture. Although originally intended merely as a means for obtaining user feedback for use in designing a "real" system, the application has been adopted for use by our Department of Surgery. As they begin to use the application, they have suggested changes and we have responded. This paper illustrates some of the advantages we have found for prototyping with Web-based applications, including security aspects.

Computer-Assisted Instruction, Education, Medical, General Surgery education, Humans, Computer Simulation, Surgical Procedures, Operative, and Telemedicine

We are seeing the emergence of medical applications for virtual reality (VR). These include telepresence surgery, three-dimensional (3-D) visualization of anatomy for medical education, VR surgical simulators, and virtual prototyping of surgical equipment and operating rooms. Today, approximately 90% of the knowledge a physician requires can be obtained through electronic means, such as diagnostic sensors and imaging modalities, directly seeing the patient with a video camera for medical consultation, or using electronic medical records. In addition, with telepresence, a therapy can be effected electronically, regardless of the physical location of the patient. Therefore, it makes sense to send the electronic information or manipulation, rather than sending the patient or blood samples, to obtain tests or to produce a cure. In that these applications are mediated through the computer interface, they are the embodiment of VR as the major force for change in the field of medicine. The Green Telepresence Surgery System consists of two components, the surgical workstation and the remote worksite. At the remote site are a 3-D camera system and responsive manipulators with sensory input. At the workstation are a 3-D monitor and dexterous handles with force feedback. The next generation in medical education can learn anatomy from a new perspective by "flying" inside and around the organs, using sophisticated computer systems and 3-D visualization. The VR surgical simulator is a stylized recreation of the human abdomen with several essential organs. Using this, students and surgeons can practice surgical procedures with virtual scalpels and clamps. To support these advanced technologies, the operating room and hospital of the future will first be designed and tested in virtual reality, allowing multiple iterations of equipment and surgical rooms before they are actually built. Insofar as all these technologies are based on digital information, they are the building blocks for the digital physician of the 21st century.

The objective of this study is to establish a protocol for the technical and clinical evaluation of a workstation for the planning of stereotactic neurosurgical interventions that has been developed in the framework of a joint European research project. Although several such workstations have been proposed before, they lacked the final and most important step, that of clinical validation. They failed to rigorously prove that their product was useful. The authors present a new method that is applicable to the evaluation of a wide range of medical technologies. Their protocol basically assesses the clinical relevance of the user requirements that are at the root of the development of the new technology. The evaluation consists of two stages. During functional specification, iterative prototyping is used to establish the clinical requirements and to assure the quality of the final product. A case study design is used in a second stage that assesses the clinical usability. A before-after study gives a first indication of cost effectiveness and improvement of health care quality.

Computer Graphics, Heart diagnostic imaging, Humans, Magnetic Resonance Imaging, Reproducibility of Results, Respiratory System anatomy histology, Software, Software Design, Tomography, X-Ray Computed, Image Processing, Computer-Assisted methods, and User-Computer Interface

The utility of three-dimensional (3D) medical imaging is hampered by difficulties in extracting anatomical regions and making measurements in 3D images. Presently, a user is generally forced to use time-consuming, subjective, manual methods, such as slice tracing and region painting, to define regions of interest. Automatic image-analysis methods can ameliorate the difficulties of manual methods. This paper describes a graphical user interface (GUI) system for constructing automatic image-analysis processes for 3D medical-imaging applications. The system, referred to as IMPROMPTU, provides a user-friendly environment for prototyping, testing and executing complex image-analysis processes. IMPROMPTU can stand alone or it can interact with an existing graphics-based 3D medical image-analysis package (VIDA), giving a strong environment for 3D image-analysis, consisting of tools for visualization, manual interaction, and automatic processing. IMPROMPTU links to a large library of 1D, 2D, and 3D image-processing functions, referred to as VIPLIB, but a user can easily link in custom-made functions. 3D applications of the system are given for left-ventricular chamber, myocardial, and upper-airway extractions.

Hospital Records, Image Processing, Computer-Assisted, Software, and Radiotherapy, Computer-Assisted instrumentation

Purpose: We have developed a software tool for interactively verifying treatment plan implementation. The Electronic View Box (EVB) tool copies the paradigm of current practice but does so electronically. A portal image (online portal image or digitized port film) is displayed side by side with a prescription image (digitized simulator film or digitally reconstructed radiograph). The user can measure distances between features in prescription and portal images and "write" on the display, either to approve the image or to indicate required corrective actions. The EVB tool also provides several features not available in conventional verification practice using a light box.
Methods and Materials: The EVB tool has been written in ANSI C using the X window system. The tool makes use of the Virtual Machine Platform and Foundation Library specifications of the NCI-sponsored Radiation Therapy Planning Tools Collaborative Working Group for portability into an arbitrary treatment planning system that conforms to these specifications. The present EVB tool is based on an earlier Verification Image Review tool, but with a substantial redesign of the user interface. A graphical user interface prototyping system was used in iteratively refining the tool layout to allow rapid modifications of the interface in response to user comments.
Results: Features of the EVB tool include 1) hierarchical selection of digital portal images based on physician name, patient name, and field identifier; 2) side-by-side presentation of prescription and portal images at equal magnification and orientation, and with independent grayscale controls; 3) "trace" facility for outlining anatomical structures; 4) "ruler" facility for measuring distances; 5) zoomed display of corresponding regions in both images; 6) image contrast enhancement; and 7) communication of portal image evaluation results (approval, block modification, repeat image acquisition, etc.).
Conclusion: The EVB tool facilitates the rapid comparison of prescription and portal images and permits electronic communication of corrections in port shape and positioning.

Aerospace Medicine, Auditory Perception, Computer Graphics, Computer Peripherals, Computer Simulation, Data Display, Environment Design, Humans, Military Personnel psychology, Touch physiology, Visual Perception physiology, Aircraft, Electroencephalography instrumentation, Signal Processing, Computer-Assisted, and User-Computer Interface

The term Fusion Interface is defined as a class of interface which integrally incorporates both virtual and non-virtual concepts and devices across the visual, auditory and haptic sensory modalities. A fusion interface is a multi-sensory virtually-augmented synthetic environment. A new facility has been developed within the Human Engineering Division of the Armstrong Laboratory dedicated to exploratory development of fusion-interface concepts. One of the virtual concepts to be investigated in the Fusion Interfaces for Tactical Environments facility (FITE) is the application of EEG and other physiological measures for virtual control of functions within the flight environment. FITE is a specialized flight simulator which allows efficient concept development through the use of rapid prototyping followed by direct experience of new fusion concepts. The FITE facility also supports evaluation of fusion concepts by operational fighter pilots in a high fidelity simulated air combat environment. The facility was utilized by a multi-disciplinary team composed of operational pilots, human-factors engineers, electronics engineers, computer scientists, and experimental psychologists to prototype and evaluate the first multi-sensory, virtually-augmented cockpit. The cockpit employed LCD-based head-down displays, a helmet-mounted display, three-dimensionally localized audio displays, and a haptic display. This paper will endeavor to describe the FITE facility architecture, some of the characteristics of the FITE virtual display and control devices, and the potential application of EEG and other physiological measures within the FITE facility.

evolutionary prototyping, Information technology, T58.5-58.64, Electronic computers. Computer science, and QA75.5-76.95

The failure of many Information Systems (IS) designed for use by managers may be due to the fact that traditional IS methodologies were used in their development. In this paper we describe an organisation's efforts, over a period of four years, to develop an IS for use by senior management and show how traditional methodologies have impeded the involvement of the intended users of the system from the development process resulting in poor specification of user requirements and inflexible systems. From this experience we verify the superiority of an evolutionary prototyping methodology for the development of these types of systems.

Automation economics, Costs and Cost Analysis, Humans, Language, United States, Vocabulary, Speech, Speech Perception, Telecommunications trends, Telephone economics, User-Computer Interface, and Voice

As the telecommunications industry evolves over the next decade to provide the products and services that people will desire, several key technologies will become commonplace. Two of these, automatic speech recognition and text-to-speech synthesis, will provide users with more freedom on when, where, and how they access information. While these technologies are currently in their infancy, their capabilities are rapidly increasing and their deployment in today's telephone network is expanding. The economic impact of just one application, the automation of operator services, is well over $100 million per year. Yet there still are many technical challenges that must be resolved before these technologies can be deployed ubiquitously in products and services throughout the worldwide telephone network. These challenges include: (i) High level of accuracy. The technology must be perceived by the user as highly accurate, robust, and reliable. (ii) Easy to use. Speech is only one of several possible input/output modalities for conveying information between a human and a machine, much like a computer terminal or Touch-Tone pad on a telephone. It is not the final product. Therefore, speech technologies must be hidden from the user. That is, the burden of using the technology must be on the technology itself. (iii) Quick prototyping and development of new products and services. The technology must support the creation of new products and services based on speech in an efficient and timely fashion. In this paper I present a vision of the voice-processing industry with a focus on the areas with the broadest base of user penetration: speech recognition, text-to-speech synthesis, natural language processing, and speaker recognition technologies. The current and future applications of these technologies in the telecommunications industry will be examined in terms of their strengths, limitations, and the degree to which user needs have been or have yet to be met. Although noteworthy gains have been made in areas with potentially small user bases and in the more mature speech-coding technologies, these subjects are outside the scope of this paper.

Humans, Larynx, Artificial, Tomography, X-Ray Computed, Trachea anatomy histology, Trachea diagnostic imaging, Models, Biological, and Tracheostomy

The availability of an accurate three-dimensional (3-D) model of the tracheostoma and trachea of the laryngectomy patient would be of great help in prototyping of endotracheal prostheses. Stereolithography has been described for skull and jaw models but never for soft-tissue reconstructions of the trachea. CT was performed on tracheostomas of 8 patients. The CT data were used to make 3-D models by means of stereolithography. Inverted CT data were used to create air contour models of the same tracheostomas. Eight soft-tissue and 8 air contour models were reconstructed from CT data, showing accuracy and great detail. In this paper we present a previously unreported application of the stereolithography technique. Measurements and prosthesis prototyping, which are impossible to perform on tracheostomas in patients, can now be executed safely. We are using the 3-D tracheostoma models in our research project to develop an endotracheal fixation method for tracheostomal valves.

Computer Security, Equipment Failure, Software, Computer Communication Networks, and Computer Systems

SQLGEN is a framework for rapid client-server relational database application development. It relies on an active data dictionary on the client machine that stores metadata on one or more database servers to which the client may be connected. The dictionary generates dynamic Structured Query Language (SQL) to perform common database operations; it also stores information about the access rights of the user at log-in time, which is used to partially self-configure the behavior of the client to disable inappropriate user actions. SQLGEN uses a microcomputer database as the client to store metadata in relational form, to transiently capture server data in tables, and to allow rapid application prototyping followed by porting to client-server mode with modest effort. SQLGEN is currently used in several production biomedical databases.

Face anatomy histology, Face diagnostic imaging, Humans, Image Processing, Computer-Assisted, Radiography, Skull anatomy histology, Skull diagnostic imaging, Computer Simulation, Diagnostic Imaging methods, Face surgery, Skull surgery, and Surgery, Plastic

Via an inverse approach to that of the Renaissance painter's treatment of perspective, the third dimension must be obtained from flat radiological information in order to reconstitute (virtually and materially) the volumes which it analyses. These images are analysed mathematically by computer. The applications are and will be numerous, especially in cranio-maxillo-facial surgery. Surgical simulation, without claiming to assess their soft tissue repercussions, section and virtually reposition bone segments: symmetrization and correction of hypotrophy are easy to visualize; computer-assisted surgical teaching applications (endoscopic surgery) are discussed. Multimodal images superimpose information from various sources: operative views and pre-recorded images are available to the surgeon and guide him in his "surgical navigation". Prototyping of skeletal anatomical specimens (prior to tumour or soft tissue specimens) provides the therapist with a precise preoperative spatial configuration of the abnormalities to be corrected, and the reconstructions to be performed. These developments, and others to come, are the sole objective of 3D imaging, beautiful in itself, but ineffective alone.

Software Design, Computer Communication Networks standards, Hospital Information Systems standards, Software standards, and Systems Integration

Componentized software promises easier, more fine-grained integration of disparate software systems. Variations of the technology can help to achieve tight coupling among disparate programs on the clinical workstation or across wide area networks. HL7 members have been designing extensions to the protocol for the exchange of healthcare information using Microsoft OLE and CORBA technologies. Extensive prototyping has been performed, including the simultaneous interconnection of sixteen different vendor systems exchanging demographic data and lab results. The first release of this standard will be notable in that the specifications for OLE and CORBA will be entirely isomorphic, they will be based directly, on HL7 version 2.3, and they may easily be implemented in systems that are not written using object-oriented programming tools. As HL7 version 3 is developed on an object-oriented model of healthcare information, the same approach will be used so information about the objects may be shared using CORBA and OLE.

Computer Graphics, Computer Systems, Humans, Hypermedia, Image Processing, Computer-Assisted, User-Computer Interface, Brain Mapping, Computer Communication Networks, and Software

The Web provides a rapid prototyping environment for building platform-independent graphical user interfaces. A Web-based console can be implemented as a suite of CGI scripts that generate HTML code, manipulate files, execute system commands, and invoke external tools. Often these tools share data by reading and writing flat files, which must be explicitly maintained by the CGI programmer. In a repository system, meta-data about each file object are maintained in a database, and access to all data is regulated by a layer of control services. This paper describes the design and implementation of a Web-based Repository Manager (WRM), which provides an application programmer's interface for controlling applications, generating HTML documents, handling Web forms, and managing multi-media data. The WRM is being used to develop a console for the Brain Mapping Framework, a system for visualizing cortical stimulation data obtained during neurosurgery.

General Surgery, Internship and Residency, Methods, Software, Systems Integration, Attitude to Computers, Computer Communication Networks, Computer Systems, Hospital Information Systems statistics numerical data, and Medical Records Systems, Computerized statistics numerical data

Construction of applications using the World Wide Web architecture and Hypertext Markup Language (HTML) documents is relatively simple. We are exploring this approach with an application, called PolyMed now in use by surgical residents for one year. We monitored use and obtained user feedback to develop new features and eliminate undesirable ones. The system has been used to keep track of over 4,200 patients. We predicted, several advantages and disadvantages to this approach to prototyping clinical applications. Our experience confirms some advantages (ease of development and customization, ability to exploit non-Web system components, and simplified user interface design) and disadvantages (lack of database management services). Some predicted disadvantages failed to materialize (difficulty modeling a clinical application with hypertext and inconveniences associated with the "connectionless" nature of the Web). We were disappointed to find that while integration of external Web applications (such as Medline) into our application was easy, our users did not find it useful.

Computer software and QA76.75-76.765

To naturally and conveniently express numerical algorithms, considerable expressive power is needed in the languages in which they are implemented. The language Matlab is widely used by numerical analysts for this reason. Expressiveness or ease-of-use can also result in a loss of efficiency, as is the case with Matlab. In particular, because numerical analysts are highly interested in the performance of their algorithms, prototypes are still often implemented in languages such as Fortran. In this article we describe a language design that is intended to both provide expressiveness for numerical computation, and at the same time provide performance guarantees. In our language, EQ, we attempt to include both syntactic and semantic features that correspond closely to the programmer's model of the problem, including unordered equations, large-granularity state transitions, and matrix notation. The resulting language does not fit into standard language categories such as functional or imperative but has features of both paradigms. We also introduce the notion of language dependability, which is the idea that a language should guarantee that certain program transformations are performed by all implementations. We first describe the interesting features of EQ, and then present three examples of algorithms written using it. We also provide encouraging performance results from an initial implementation of our language.

Two-photon excitation of carriers in boron E'-center-containing borosilicate glasses results in a photoencoding of selectively etchable regions. Using a turbulent etching process followed by polishing, we have demonstrated a number of patterning capabilities for microtechnology applications such as ultrafast capillary electrophoresis chips and rapid prototyping of diffractive optical elements.

Present-day computational fluid dynamics (CFD) techniques can be used to analyze the behavior of fluid flow in a variety of pumps. CFD can be a powerful tool during the design stage for rapid virtual prototyping of different designs, analyzing performance parameters, and making design improvements. Computational flow solutions provide information such as the location and size of stagnation zones and the local shear rate. These parameters can be correlated to the extent of hemolysis and thrombus formation and are critical to the success of a blood pump. CFD-ACE, an advanced commercial CFD code developed by CFD Research Corporation, has been applied to fluid flows in rotary machines, such as axial flow pumps and inducers. Preprocessing and postprocessing tools for efficient grid generation and advanced graphical flow visualization are integrated seamlessly with CFD-ACE. The code has structured multiblock grid capability, non-Newtonian fluid treatment, a variety of turbulence models, and an Eulerian-Lagrangian particle tracking model. CFD-ACE has been used successfully to study the flow characteristics in an axial flow blood pump. An unstructured flow solver that greatly automates the process of grid generation and speeds up the flow simulation is under development.
(© 1996 International Society for Artificial Organs.)

Biocompatible Materials, Blood Flow Velocity physiology, Computer Simulation, Heart-Assist Devices adverse effects, Hemolysis, Pressure, Equipment Design trends, and Heart-Assist Devices standards

Present-day computational fluid dynamics (CFD) techniques can be used to analyze the behavior of fluid flow in a variety of pumps. CFD can be a powerful tool during the design stage for rapid virtual prototyping of different designs, analyzing performance parameters, and making design improvements. Computational flow solutions provide information such as the location and size of stagnation zones and the local shear rate. These parameters can be correlated to the extent of hemolysis and thrombus formation and are critical to the success of a blood pump. CFD-ACE, an advanced commercial CFD code developed by CFD Research Corporation, has been applied to fluid flows in rotary machines, such as axial flow pumps and inducers. Preprocessing and postprocessing tools for efficient grid generation and advanced graphical flow visualization are integrated seamlessly with CFD-ACE. The code has structured multiblock grid capability, non-Newtonian fluid treatment, a variety of turbulence models, and an Eulerian-Langrangian particle tracking model. CFD-ACE has been used successfully to study the flow characteristics in an axial flow blood pump. An unstructured flow solver that greatly automates the process of grid generation and speeds up the flow simulation is under development.

Anatomy, Cross-Sectional, Humans, Quality Control, Software, User-Computer Interface, Computer Communication Networks, Image Processing, Computer-Assisted, and Radiology Information Systems

Internet access to mixed text/image databanks is finding application in the medical world. An example is a database of medical X-rays and associated data consisting of demographic, socioeconomic, physician's exam, medical laboratory and other information collected as part of a nationwide health survey conducted by the government. Another example is a collection of digitized cryosection images, CT and MR taken of cadavers as part of the National Library of Medicine's Visible Human Project. In both cases, the challenge is to provide access to both the image and the associated text for a wide end user community to create atlases, conduct epidemiological studies, to develop image-specific algorithms for compression, enhancement and other types of image processing, among many other applications. The databanks mentioned above are being created in prototype form. This paper describes the prototype system developed for the archiving of the data and the client software to enable a broad range of end users to access the archive, retrieve text and image data, display the data and manipulate the images. System design considerations include; data organization in a relational database management system with object-oriented extensions; a hierarchical organization of the image data by different resolution levels for different user classes; client design based on common hardware and software platforms incorporating SQL search capability, X Window, Motif and TAE (a development environment supporting rapid prototyping and management of graphic-oriented user interfaces); potential to include ultra high resolution display monitors as a user option; intuitive user interface paradigm for building complex queries; and contrast enhancement, magnification and mensuration tools for better viewing by the user.

The effect of key shape on a touchscreen simulation of a flat touch-sensitive keypad was investigated by rapid prototyping. A software prototype was developed of a hardware keypad that controlled chemical analysis equipment. The prototype was used to answer some basic ergonomics questions concerning the design of the device keys. In a target selection task, keys shaped as equilateral triangles were most precise, and least precise was a compound shape comprising of a rectangular lower part and a triangular 'hat' as the upper part. No significant differences in the times taken to complete the task were found. It is suggested that the use of a touchscreen prototype is suitable when designing flat-keypad layouts. Due to the visual nature of flat keypad use, where perception of the target must counter reduced tactile feedback, the design of shapes to aid the selection of keys is of paramount importance. It is concluded that rapid prototyping of hardware with graphical designs and touchscreens is a powerful tool for the ergonomic design of interfaces.

Concurrent Engineering, Integrated Product Development, Prototyping, Quality Function Deployment, Design for Manufacturing, Case histories and web-based tutorial, Manufactures, and TS1-2301

This paper provides a comprehensive insight into current trends and developments in Concurrent Engineering for integrated development of products and processes with the goal of completing the entire cycle in a shorter time, at lower overall cost and with fewer engineering design changes after product release. The evolution and definition of Concurrent Engineering are addressed first, followed by a concise review of the following elements of the concurrent engineering approach to product development: Concept Development: The Front-End Process, identifying Customer Needs and Quality Function Deployment, Establishing Product Specifications, Concept Selection, Product Architecture, Design for Manufacturing, Effective Rapid Prototyping, and The Economics of Product Development. An outline of a computer-based tutorial developed by the authors and other graduate students funded by NASA ( accessible via the world-wide-web ). is provided in this paper. A brief discussion of teamwork for successful concurrent engineering is included, t'ase histories of concurrent engineering implementation at North American and European companies are outlined with references to textbooks authored by Professor Menon and other writers. A comprehensive bibliography on concurrent engineering is included in the paper.

Cholesterol, Guideline Adherence, Humans, Computer Communication Networks, Database Management Systems, Hyperlipidemias therapy, and Practice Guidelines as Topic

DMS is a Web-based disease-management system, which facilitates easy access for users and close connection to hospital information systems, based on clinical practice guidelines. Currently we are prototyping DMS in the area of hyperlipidemia management. However our approach is general. For each office visit, DMS generates an encounter form with recommendations based on the National Cholesterol Education Program (NCEP) guidelines. In between visits, DMS provides email notifications to clinicians about delinquent laboratory studies and recommendations for patient management based on recently available information. By reviewing previous efforts for implementing NCEP guidelines and some of the pitfalls that were encountered, we first constructed DMS for hyperlipidemia management. A detailed description of DMS is provided in this paper.

Adult, Aged, Female, Humans, Image Processing, Computer-Assisted, Male, Middle Aged, ROC Curve, Radiography, Calcaneus diagnostic imaging, Calcaneus injuries, and Fractures, Bone diagnostic imaging

The purpose of this study was to evaluate and compare the diagnostic performance of stereolithography vs workstation-based three-dimensional (3D) reformations in intra-articular calcaneal fractures. A total of 30 intra-articular calcaneal fractures were examined using standard radiographs, coronal CT scans, and 2D and 3D reformations. The CT data were transferred to an outside institution, and stereolithograms were produced from photopolymer resin employing a laser beam system. 3D reformations and stereolithograms were analyzed in a blinded fashion by two staff radiologists. Receiver-operating-characteristic (ROC) curves were obtained for six clinically significant fracture components. Standard radiographs, coronal CT scans, and 2D reformations served as the standard of reference. The area under the ROC curves for 3D reformations and stereolithograms were 1.0 and 0.98 for abnormal tuber angles, 0.91 and 0.91 for anterior and middle talo-calcaneal joint involvement, 0. 90 and 0.95 for involvement of the posterior talo-calcaneal joint, 0. 65 and 0.78 for the presence of a lateral bulge, 0.80 and 0.81 for the involvement of the calcaneocuboidal joint, and 0.62 and 0.67 for the presence of a "tongue-type" fracture. No statistically significant difference was demonstrated for the two methods (Wilcoxon signed-rank test, p = 0.138). Based on our results stereolithograms did not prove to be statistically superior to workstation-based 3D reformations. Stereolithograms may still be useful for teaching purposes and for surgical planning at a thinking-efficacy level.

Adult, Biomedical Engineering instrumentation, Biomedical Engineering methods, Cephalometry instrumentation, Cephalometry methods, Craniosynostoses pathology, Evaluation Studies as Topic, Femur anatomy histology, Hip Prosthesis, Humans, Image Processing, Computer-Assisted instrumentation, Infant, Magnetic Resonance Imaging methods, Tomography, X-Ray Computed methods, Image Processing, Computer-Assisted methods, Lasers, and Models, Anatomic

Rapid prototyping techniques, originally developed for building components from computer aided designs in the motor industry, are now being applied in medicine to build models of human anatomy from high resolution multiplanar imaging data such a computed tomography (CT). The established technique of stereolithography and the more recent selective laser sintering (SLS), both build up an object layer by layer. Models have applications in surgical planning, for the design of customised implants and for training. Preliminary experience of using the SLS technique for medical applications is described, addressing questions regarding image processing, data transfer and manufacture. Pilot models, built from nylon, included two skills (a child with craniosynoslosis and an adult with hypertetorism) and a normal femur which was modelled for use in a bioengineering test of an artificial hip. The dimensions of the models were found to be in good agreement with the CT data from which they were built-for the child's skull the difference between the model and the CT data was less than 1.0 +/- 0.5 mm in each direction. Our experience showed that, with care, a combination of existing software packages may be used for data conversion. Ideally, image data of high spatial resolution should be used. The pilot models generated sufficient clinical interest for the technique to be pursued in the orthopaedic field.

Computer Graphics, Humans, Image Processing, Computer-Assisted, Mandible diagnostic imaging, Pilot Projects, Reproducibility of Results, Mandible anatomy histology, Models, Anatomic, and Tomography, X-Ray Computed methods

We investigate the accuracy of complex anatomical replicas derived from X-ray computed tomography data linked to the rapid prototyping technique of stereolithography. Data processing by specific softwares (segmentation, three-dimensional interpolation) allows direct interfacing with the stereolithography apparatus to build a resin replica with reproduction of internal cavities. Our preliminary results about surface and dimensional accuracies suggest that the reproduction of complex anatomical structures by stereolithography is reliable enough to be used for surgical planning, for custom-made implants and for surgical anatomy teaching.

Adolescent, CD-ROM, Female, Health Promotion, Humans, Male, Program Evaluation, Software, United Kingdom, Computer-Assisted Instruction, and Sex Education methods

This article describes an interactive prototyping model for development of four computer software modules for British youth on sexual issues. An iterative cycle of development, user review and feedback, and subsequent modification and retesting was used with approximately 150 young adults, with particular attention to presentation style, screen design, usability, relevance of material, enjoyment, and learning. The software was designed to be realistically accommodated in school settings, to be used as a reference tool by students working alone or in a group teaching situation. Feedback from youth and adults attests to the feasibility of development, implementation, and instructional usefulness. Interactive prototyping proved essential in the face of skepticism from teachers concerning young people's information needs and acceptance of a computerized educational approach.

Three-dimensional periodic microstructures of aluminum oxide, which are important for creating photonic band-gap structures (PBGs), were fabricated by laser rapid prototyping by means of laser-induced direct-write deposition from the gas phase. The structures consisted of layers of parallel rods forming a face-centered tetragonal lattice with lattice constants of 66 and 133 micrometers. These structures showed transmission minima centered around 4 terahertz (75 micrometers) and 2 terahertz (150 micrometers), respectively. PBGs will allow precise control of the optical properties of materials, including lasers without threshold.

Adult, Costs and Cost Analysis, Female, Humans, Male, Pelvic Bones surgery, Preoperative Care, Time Factors, Tomography, X-Ray Computed economics, Tomography, X-Ray Computed methods, User-Computer Interface, Computer Simulation, Models, Anatomic, and Pelvic Bones diagnostic imaging

X-ray or CT images allows only a limited three-dimensional orientation in presurgical planning. Especially for the planning of internal hemipelvectomies with custom-made endoprosthesis and for peri-acetabular osteotomies a high-grade orientation is necessary. This orientation is improved by a 3D CT-controlled manufactured 1:1 model of the pelvis. This enables and exact classification of defect and deformity, planning of resection planes, design of the suitable custom-made implant and simulation of the operation technique as preoperative quality control.

Child, Facial Asymmetry diagnostic imaging, Facial Asymmetry surgery, Facial Bones diagnostic imaging, Facial Bones injuries, Female, Humans, Image Processing, Computer-Assisted methods, Male, Computer-Aided Design, Facial Bones surgery, Magnetic Resonance Imaging, Models, Anatomic, and Tomography, X-Ray Computed

The rapid advances in computer technology, often driven by the demands of industry, have created new possibilities in surgery which previous generations of surgeons could only have imagined. Improved imaging with computerised tomography (CT) has been followed by magnetic resonance imaging (MRI) and, more recently, it has become possible to reformat the data as three-dimensional images. Computer technology has new moved forward with the advent of rapid prototyping techniques (RPT) which allow both the production of models of the hard tissues and custom-made prostheses from computerised scanning data. In this article we review the development and current technologies available in RPT and the applications of this advance in surgery and illustrate this with two case reports.

Humans, Diagnostic Imaging methods, Image Processing, Computer-Assisted, Microcomputers, and Software

A 32-bit PC-based 3D medical image processing software package is presented. Its basic functions are the display and manipulation of medical images and the inclusion of user-written processing routines in C language. This software runs on inexpensive hardware and is easy to learn. It means the current needs of many research teams working in medical image processing.

Biomedical Engineering, Computer-Aided Design, Female, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Middle Aged, Models, Anatomic, Prosthesis Design, Thorax anatomy histology, and Heart, Artificial

The failure of the orthotopic implantation of a totally implantable artificial heart (TAH) was due mainly to anatomic mismatches in the conduits of the conventional TAH system. To overcome this anatomic incompatibility, a custom design and fabrication process was designed using the rapid prototyping (RP) technique. After three dimensional reconstruction of magnetic resonance imaging of the thoracic cavity and vascular remnants of the recipient, study of anatomic fit was done using the reconstructed thoracic model and three dimensional computer aided design (CAD) model. The direction of the inflow and outflow conduits of the blood sac was changed with a Unigraphics CAD. The RP model of the designed chamber was fabricated and examined for anatomic compatibility. Through this approach, the minute directional mismatch of the inflow and outflow conduits was improved. Thus, a new custom designed moving actuator Korean TAH with CAD and RP techniques was developed.

Computer Systems, Humans, Internet standards, Software standards, Systems Integration, Practice Guidelines as Topic, and Programming Languages

Much work has been done in the area of web-based clinical practice guidelines. Issues such as representation, description, architectures, and implementation have been explored previously. Most if not all of these web-based applications rely exclusively on HTML, the HyperText Markup Language. In the process of prototyping a guideline service to be used in a diabetes operations improvement project, we developed a model for a guideline engine that makes use of the Extensible Markup Language (XML), both as an interface to the engine and as a vehicle for delivering structured guideline content. We feel that XML may offer advantages in implementing guideline services that are difficult (if not impossible) to accomplish with HTML alone.

Cerebrospinal Fluid physiology, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Neurosurgery education, Patient Care Planning, Research, Resins, Synthetic, Rheology, Teaching Materials, Cerebral Ventricles anatomy histology, Computer-Aided Design, and Models, Anatomic

As part of our research into the fluid hydrodynamics of the human ventricular system, a fused deposition model of the human ventricular system was made using magnetic resonance imaging (MRI) data. This article describes the manufacturing of a positive cast of the ventricles as a first step in the construction of a hollow model. After decryption of the original MRI file (ACR-Nema format), the MRI slices were reassembled semiautomatically and a rapid prototyping station produced a resin model. Because of its ease and speed, this method harbors great potential for teaching purposes, research, and preoperative planning in complex three-dimensional soft tissue targets.

Biological circuitry in the brain that has been associated with the Parzen method of classification inspired an analog CMOS binary pattern classifier. The circuitry resides on three separate chips. The first chip computes the closeness of a test vector to each training vector stored on the chip where "vector closeness" is defined as the number of bits two vectors have in common above some thresholds. The second chip computes the closeness of the test vector to each possible category where "category closeness" is defined as the sum of the closenesses of the test vector to each training vector in a particular category. Category closenesses are coded by currents which feed into an "early bird" winner-take-all circuit on the third chip that selects the category closest to the test vector. Parzen classifiers offer superior classification accuracy than the common nearest neighbor Hamming networks. A high degree of parallelism allows for O(1) time complexity and the chips are tillable for increased training vector storage capacity. Proof-of-concept chips were fabricated through the MOSIS chip prototyping service and successfully tested.

Computer systems in today's society require an increasing amount of embedded software and hardware systems. Their application has introduced new problems for the software engineer combined with the complexity of such systems. In particular, the early stages of the software development process are vital for the successful implementation of computer systems. High order Petri nets are introduced and extended as a powerful formalism for the specification and analysis of concurrent systems. A tool called SystemSpecs has been applied that supports rapid system prototyping with such nets. This survey article provides techniques for early systems analysis that can be used as a real time system prototype for customer presentations. Small examples are extracted from industrial applications to indicate how the described techniques can be used. While the major disadvantage of typical net descriptions is their visual complexity that makes them useless for large distributed systems, the paper also describes how to find overly complex structures, and describes selected methods of how to refine such structures.

Elasticity, Feasibility Studies, Models, Biological, Prosthesis Design, Stress, Mechanical, Titanium, Biocompatible Materials, Chromium Alloys, and Hip Prosthesis

Previous studies have suggested that a controlled stiffness prosthesis is required to address the conflicting requirements of minimizing stress shielding and micromotion. The design for a controlled stiffness prosthesis is proposed and a preliminary analytical investigation performed to assess its predicted performance before fabrication of a prototype component. The novel prosthesis consisted of a cobalt-chrome core and a flexible composite outer layer. Varying the composite layer thickness allowed the prosthesis stiffness to be controlled. Three variants of the controlled stiffness prosthesis were critically assessed using the finite element method and their predicted performance compared with those of conventional prosthesis designs. The potential for stress shielding was assessed by examining the periosteal strain energy and the potential for migration assessed by examining the endosteal minimum principal cancellous bone stresses. Both the conventional and controlled stiffness implants performed poorly as press-fit prostheses. All the press-fit prostheses generated high cancellous bone stresses, suggesting that excessive migration of these implants would be likely. The controlled stiffness implants performed better than the conventional implants when bonded to the surrounding bone. Although the controlled stiffness implants did not eliminate stress shielding of the calcar, they produced higher strain energies than the conventional designs. The findings of this study are that osseointegrated controlled stiffness implants may perform better than current osseointegrated cementless prostheses and therefore it is worth while progressing to the next stage, of prototyping an implant.

Adult, Clavicle injuries, Female, Fractures, Bone diagnostic imaging, Fractures, Bone surgery, Humans, Radiography, Scapula injuries, Computer Simulation, Computer-Aided Design, Models, Anatomic, and Orthopedic Procedures

The revision of an orthopaedic procedure can present surgeons with the challenge of a complex reconstructive process. Orthopaedic surgery can also face considerable challenges in cases presenting extensive primary injuries with multiple bone fragmentation, as well as in cases presenting bone deformities. Radiographs are used routinely for orthopaedic surgical planning, yet they provide inadequate information on the precise three-dimensional extent of bone defects. Three-dimensional reconstructions from X-ray computed tomography offer superior visualization but are not portable for consultation or readily available in the operating theatre for guidance during a procedure. A physical model manufactured from X-ray computed tomography data can offer surgeons a clear understanding of complex anatomical detail, by providing an intuitive physical relationship between patient and model. Rapid prototyping was used for the construction of an anatomical model in a case presenting with a complex shoulder injury. The model provided a definitive interpretation of joint pathology and enabled a full assessment of the degree of injury.

Computer Systems, Curriculum, Ear anatomy histology, Ear surgery, Humans, Software, Temporal Bone anatomy histology, Computer Simulation, Computer-Assisted Instruction instrumentation, Image Processing, Computer-Assisted instrumentation, Microsurgery instrumentation, Models, Anatomic, Otolaryngology education, Temporal Bone surgery, and Tomography, X-Ray Computed instrumentation

Learning microsurgery of the middle ear requires preparations of temporal bones. Ethical and moral restrictions in obtaining specimens make training and research with temporal bone preparations increasingly more difficult. Due to the complex structure of the temporal bone with its communicating cavities, the manufacture of facsimiles up to now has been impossible. Rapid prototyping techniques must be able to produce identical objects from an original one. By using CT scans of temporal bones from anatomic preparations and patients we have been able to reconstruct 3D pictures on a CAD workstation. We are now able to incorporate data in a stereolithographic system to create an anatomic facsimile of the temporal bone. It is possible to produce a considerable number of these facsimiles from the same real object. With this method we can produce models of human structure for medical teaching, training and research. Our artificial preparations of temporal bones correspond to both the material characteristics and anatomic details of human structures, allowing various surgical exercises to be carried out.

Databases as Topic, Heart Transplantation, Humans, Interinstitutional Relations, Kidney Transplantation, Liver Transplantation, Lung Transplantation, Microcomputers, Pancreas Transplantation, Computer Communication Networks, Information Systems, and Transplantation

realidade virtual, simulação, manufatura virtual, prototipação virtual, virtual reality, simulation, virtual manufacturing, virtual prototyping, Industrial engineering. Management engineering, and T55.4-60.8

A realidade virtual é um ambiente gerado pelo computador em que o usuário tem disponibilidade de controles tridimensionais de maneira altamente interativa, podendo manipular e explorar dados em tempo real. A realidade virtual pode ser aplicada em diversos setores da indústria, desde o planejamento de fábricas, simulação da produção, auxílio na divulgação de produtos, treinamento de funcionários, validação de protótipos. Este artigo visa mostrar a flexibilidade da utilização da realidade virtual dentro das indústrias e dos centros de pesquisas, focando principalmente as áreas relacionadas a manufatura, desenvolvimento de produto e treinamento.Virtual reality is a computer-generated environment with highly interactive three-dimensional controls which allow the user to manipulate and examine data in real time. Virtual reality can be applied in a number of industry sectors, including factory planning, product simulation, product popularization, employee training and prototype validation. This article aims to show the flexibility of virtual reality in industry and in research centers, focussing mainly on areas related to manufacturing, product development and training.

Clinical Protocols, Computer Security, Internet, and Medical Records Systems, Computerized

In this paper, it is emphasized that electronic medical record systems cannot totally be developed in the traditional way. The underlying process of how physicians or nurses are searching for information is not fully understood. Therefore, a method that combines a scientific approach and prototyping is advocated. With the help of this advocated approach, these questions could be answered in a way that was also scientifically sound. In this contribution, two examples of the use of this method are presented. One concerns the determination of the optimum granularity of the narrative parts of the electronic healthcare record (EHCR) and the other concerns the use and impact of stand-alone protocol systems.

This paper describes a procedure that makes it possible to design and fabricate (including sealing) microfluidic systems in an elastomeric material [Formula: see text] poly(dimethylsiloxane) (PDMS) [Formula: see text] in less than 24 h. A network of microfluidic channels (with width >20 μm) is designed in a CAD program. This design is converted into a transparency by a high-resolution printer; this transparency is used as a mask in photolithography to create a master in positive relief photoresist. PDMS cast against the master yields a polymeric replica containing a network of channels. The surface of this replica, and that of a flat slab of PDMS, are oxidized in an oxygen plasma. These oxidized surfaces seal tightly and irreversibly when brought into conformal contact. Oxidized PDMS also seals irreversibly to other materials used in microfluidic systems, such as glass, silicon, silicon oxide, and oxidized polystyrene; a number of substrates for devices are, therefore, practical options. Oxidation of the PDMS has the additional advantage that it yields channels whose walls are negatively charged when in contact with neutral and basic aqueous solutions; these channels support electroosmotic pumping and can be filled easily with liquids with high surface energies (especially water). The performance of microfluidic systems prepared using this rapid prototyping technique has been evaluated by fabricating a miniaturized capillary electrophoresis system. Amino acids, charge ladders of positively and negatively charged proteins, and DNA fragments were separated in aqueous solutions with this system with resolution comparable to that obtained using fused silica capillaries.

Anatomy, Artistic, Humans, Radiographic Image Enhancement, Terminology as Topic, Anatomy, Cross-Sectional, Medical Illustration, and Radiotherapy Planning, Computer-Assisted

We report on experience and insights gained from prototyping, for clinical radiation oncologists, a new access tool for the University of Washington Digital Anatomist information resources. This access tool is designed to integrate with a radiation therapy planning (RTP) system in use in a clinical setting. We hypothesize that the needs of practitioners in a clinical setting are different from the needs of students, the original targeted users of the Digital Anatomist system, but that a common knowledge resource can serve both. Our prototype was designed to help define those differences and study the feasibility of a full anatomic reference system that will support both clinical radiation therapy and all the existing educational applications.

Computer Systems, Decision Support Systems, Clinical, Ergonomics, Humans, Systems Integration, Workforce, Decision Making, Computer-Assisted, Expert Systems, Intensive Care Units organization administration, and Respiratory Therapy

When computer-based aids do not support the human users' decision-making strategies or anticipate the organizational impacts of technological change, advances in information technology may degrade rather than enhance decision-making performance. Such failures suggest the design of human-computer cooperation for problem solving and decision-making must be driven by human cognitive and organizational process requirements rather than computer technology. Decision- and user-centered development techniques involve domain experts and end-users in the earliest phases of design to evolve an understanding of requirements through iterative prototyping. This paper presents a collaborative approach to cognitive systems engineering applied to developing a clinical aid to assist respiratory care in the surgical ICU.

Cost Control, Esthetics, Humans, Image Processing, Computer-Assisted economics, Prosthesis Fitting, Surface Properties, Bone Plates, Computer-Aided Design economics, Image Processing, Computer-Assisted methods, Prostheses and Implants, Prosthesis Design, Skull surgery, Titanium, and Tomography, X-Ray Computed methods

This report describes a new method of custom making cranial titanium plates for the repair of skull defects. We have combined 3D CT imaging and surface modelling with rapid prototyping (RP) technology to produce physical models of our patients' skulls from which custom titanium plates were made. We have expanded the use of image processing tools applied to the CT image data to fabricate a representation of the skull defect. Medical RP models are relatively expensive and particular attention has been paid to developing image processing methods to reduce costs. Our technique used the patient as their own model and generated data from the contralateral side of the head where appropriate. We present the results of 10 patients who have had a custom made cranial titanium plate fitted and discuss the models for these cases. The benefits of our custom made titanium plates are reduced patient attendances to hospital and a more accurate titanium plate which has improved fitting and cosmesis.

The paper describes a specification model, called the Process and Data Net (PDN) model, used as the modeling tool for the M*-OBJECT information system design methodology. The model integrates the representation of static, dynamic, and behavioral aspects of a database application. PDN consists of two components: an object-oriented data model that describes static and behavioral aspects of objects of the system under analysis, and a process model that specifies a way organization activities must be coordinated. The major features of the proposed approach are: 1) the system representation captures all relevant properties from the end-user viewpoint without unnecessary details concerning implementation, 2) complex data structures and data manipulations can be specified, and 3) specifications are executable for rapid prototyping.

The study is concerned with a linguistic approach to the design of a new category of fuzzy (granular) models. In contrast to numerically driven identification techniques, we concentrate on budding meaningful linguistic labels (granules) in the space of experimental data and forming the ensuing model as a web of associations between such granules. As such models are designed at the level of information granules and generate results in the same granular rather than pure numeric format, we refer to them as linguistic models. Furthermore, as there are no detailed numeric estimation procedures involved in the construction of the linguistic models carried out in this way, their design mode can be viewed as that of a rapid prototyping. The underlying algorithm used in the development of the models utilizes an augmented version of the clustering technique (context-based clustering) that is centered around a notion of linguistic contexts-a collection of fuzzy sets or fuzzy relations defined in the data space (more precisely a space of input variables). The detailed design algorithm is provided and contrasted with the standard modeling approaches commonly encountered in the literature. The usefulness of the linguistic mode of system modeling is discussed and illustrated with the aid of numeric studies including both synthetic data as well as some time series dealing with modeling traffic intensity over a broadband telecommunication network.

Cephalometry, Communication, Computer-Aided Design, Cost-Benefit Analysis, Facial Bones diagnostic imaging, Humans, Image Processing, Computer-Assisted methods, Informed Consent, Interprofessional Relations, Lasers, Magnetic Resonance Imaging, Patient Education as Topic, Patient Satisfaction, Physician-Patient Relations, Prospective Studies, Resins, Synthetic, Skull diagnostic imaging, Surveys and Questionnaires, Technology, Radiologic, Time Factors, Facial Bones surgery, Models, Anatomic, Patient Care Planning, Skull surgery, and Tomography, X-Ray Computed

Stereolithographic (SL) biomodelling is a new technology that allows three-dimensional (3-D) computed tomography (CT) data to be used to manufacture solid plastic replicas of anatomical structures (biomodels). A prospective trial with the objective of assessing the utility of biomodelling in complex surgery has been performed. Forty-five patients with craniofacial, maxillofacial, skull base cervical spinal pathology were selected. 3-D CT or MR scanning was performed and the data of interest were edited and converted into a form acceptable to the rapid prototyping technology SL. The data were used to guide a laser to selectively polymerize photosensitive resin to manufacture biomodels. The biomodels were used by surgeons for patient education, diagnosis and operative planning. An assessment protocol was used to test the hypothesis that 'biomodels in addition to standard imaging had greater utility in the surgery performed than the standard imaging alone'. Biomodels significantly improved operative planning (images 44.09%, images with biomodel 82.21%, P < .01) and diagnosis (images 65.63%, images with biomodel 95.23%, P < .01). Biomodels were found to improve measurement accuracy significantly (image measurement error 44.14%, biomodel measurement error 7.91%, P < .05). Surgeons estimated that the use of biomodels reduced operating time by a mean of 17.63% and were cost effective at a mean price of $1031 AUS. Patients found the biomodels to be helpful for informed consent (images 63.53%, biomodels 88.54%, P < .001). Biomodelling is an intuitive, user-friendly technology that facilitated diagnosis and operative planning. Biomodels allowed surgeons to rehearse procedures readily and improved communication between colleagues and patients.

Chemistry and QD1-999

This review presents some recent developments in the field of electroanalytical sensors. We first explain the working principle of electrochemistry at the interface between two immiscible electrolyte solutions (ITIES), illustrated by the example of copper transferring through a water/1,2-dichloroethane interface when the ionophore 1,4,7,10-tetrathiacyclododecane is present in the organic phase. The obtained results show that assisted ion-transfer reactions take place with both CUI and CUII, but that the interfacial process is complicated by the fact that CUI disproportionates in water and that CUII can be reduced in the organic phase.Based on the same experimental methodology, a new type of amperometric detector for non-redox ions has been developed using a composite polymer membrane supporting a gelified organic phase that can incorporate an ionophore such as valinomycin. We report here the use of a (o-nitrophenyloctylether)-(poy(vinyl chloride) (NPOE-PVC) gel micro-interface as a detector for cations and anions in ion-exchange chromatography. The main advantage of this approach is that selectivity and sensitivity can be tailored by the choice of the ionophore and by the polarisation potential.This ion detector has also been incorporated in a miniaturised total-analysis system (?-TAS) fabricated in a polymer sheet by UV-laser photoablation. This microfabrication technique is used for the prototyping of a disposable capillary-electrophoresis microsystem comprising on-chip injector, separation column and electrochemical detector. This system is further used with built-in carbon-ink electrodes for the detection of electroactive species. These microsystems are now under development for immuno-sensor applications.

Chemistry and QD1-999

The H. Weidmann AG has set up a unique injection-moulding tool for replication of optical and nonoptical microstructures down to a sub-?m scale. Our approach simplifies the initial tooling and, thus, substantially lowers the cost threshold for feasibility studies and testing of injection-moulded microstructures. Two case studies, with micro-pipettes and a micro-spectrometer, respectively, show the usefulness of this new process technology. The service for polymer-sample prototyping is available on a commercial basis at reasonable costs and turn-around times.

Biomedical Engineering instrumentation, Equipment Design, Evaluation Studies as Topic, Humans, Models, Biological, Monitoring, Physiologic instrumentation, Respiratory Mechanics physiology, Respiratory Function Tests instrumentation, and Rheology instrumentation

During certain medical procedures, it is important to continuously measure the respiratory flow of a patient, as lack of proper ventilation can cause brain damage and ultimately death. The monitoring of the ventilatory condition of a patient is usually performed with the aid of flowmeters. However, water and other secretions present in the expired air can build up and ultimately block a traditional, restriction-based flowmeter; by using an orifice plate flowmeter, such blockages are minimized. This paper describes the design of an orifice plate flowmetering system including, especially, a description of the numerical and computational techniques adopted in order to simulate human respiratory and sinusoidal air flow across various possible designs for the orifice plate flowmeter device. Parallel computation and multigrid techniques were employed in order to reduce execution time. The simulated orifice plate was later built and tested under unsteady sinusoidal flows. Experimental tests show reasonable agreement with the numerical simulation, thereby reinforcing the general hypothesis that computational exploration of the design space is sufficiently accurate to allow designers of such systems to use this in preference to the more traditional, mechanical prototyping techniques.

Animals, Cattle, Cell Adhesion, Cells, Cultured, Culture Media chemistry, Endothelium, Vascular metabolism, Erythrocytes metabolism, Escherichia coli metabolism, Proteins metabolism, and Cell Culture Techniques methods

This paper describes the use of laminar flow of liquids in capillary systems to pattern the cell culture substrate, to perform patterned cell deposition, and to pattern the cell culture media. We demonstrate the patterning of the cell culture substrate with different proteins, the patterning of different types of cells adjacent to each other, the patterned delivery of chemicals to adhered cells, and performing enzymatic reactions over select cells or over a portion of a cell. This method offers a way to simultaneously control the characteristics of the surface to which cells are attached, the type of cells that are in their vicinity, and the kind of media that cells or part of a cell are exposed to. The method is experimentally simple, highly adaptable, and requires no special equipment except for an elastomeric relief that can be readily prepared by rapid prototyping.

Humans, Telemedicine, Electroencephalography, Epilepsy, and Information Systems

This paper describes a standardised computer-based information system for electroencephalography (EEG) focusing on epilepsy. The system was developed using a prototyping approach. It is based on international recommendations for EEG examination, interpretation and terminology, international guidelines for epidemiological studies on epilepsy and classification of epileptic seizures and syndromes and international classification of diseases. It is divided into: (1) clinical information and epilepsy relevant data; and (2) EEG data, which is hierarchically structured including description and interpretation of EEG. Data is coded but is supplemented with unrestricted text. The resulting patient database can be integrated with other clinical databases and with the patient record system and may facilitate clinical and epidemiological research and development of standards and guidelines for EEG description and interpretation. The system is currently used for teleconsultation between Gentofte and Lisbon.

Acrocephalosyndactylia surgery, Adult, Child, Preschool, Craniosynostoses surgery, Diagnostic Imaging, Goldenhar Syndrome surgery, Humans, Lasers, Osteotomy, Le Fort methods, Plastics, Polyurethanes, Resins, Synthetic, Therapy, Computer-Assisted, Computer-Aided Design, Face surgery, Models, Anatomic, Orthognathic Surgical Procedures, Patient Care Planning, and Skull surgery

Using medical models built with Rapid Prototyping (RP) technologies represents a new approach for surgical planning and simulation. These techniques allow one to reproduce anatomical objects as 3D physical models, which give the surgeon a realistic impression of complex structures before a surgical intervention. The shift from the visual to the visual-tactile representation of anatomical objects introduces a new kind of interaction called 'touch to comprehend'. As can be seen, from the presented case studies of maxillo-cranio-facial surgery, the RP models are very well suited for use in the diagnosis and the precise preoperative simulation of skeleton modifying interventions.

Biocompatible Materials, Biomechanical Phenomena, Blood Flow Velocity physiology, Blood Volume physiology, Carbon, Humans, Lead, Materials Testing, Pulsatile Flow physiology, Surface Properties, Systole, Time Factors, Torque, Videotape Recording, Heart Valve Prosthesis, Mitral Valve, and Prosthesis Design

Anatural mitral valve starts closing before systole. Conventional mechanical mitral valves start their closing motion after systole. In order to let the mechanical mitral valves start closing before systole, we propose a new self-closing valve by adjusting the center of gravity of the leaflet. As a first step, we adjusted the center of gravity by attaching a block of lead to the leaflet of a CarboMedics bileaflet valve and evaluated it using a pulse duplicator and an x-ray high-speed video camera. Comparative study was conducted under 60 bpm and 4 L/min as the mean flow rate. It was clarified that the self-closing valve started closing before systole, no influence on inflow volume was found, the final closing speed of the self-closing valve just before complete closure was slower than the conventional valve (1.9-0.34 m/s), a design strategy of a self-closing valve (sewing ring diameter 29 mm) was obtained from the experiment that momentum of inertia of the leaflet should be less than 14.9 x 10-9 kg.m2 and the torque caused by gravity should be more than 4.2 x 10-6 N. m, and only one leaflet should be designed as self-closing, and surgeons need to pay attention to the positioning of the two leaflets. In conclusion, the preliminary study showed the ability of starting to close before systole and the design strategy for future prototyping.

Fabrication of surface reliefs is achieved by raster scanning dry photopolymer films under a focused laser beam. The formation of the structure takes place subsequent to illumination without any chemical treatment or wet processing. Computer-generated optical elements can be recorded quickly, easily, and at low cost. The technology is particularly well suited for rapid prototyping and design purposes. These photopolymer films have potential in photonics applications, such as diffractive optical elements and waveguide structures.

Humans, Lasers, Magnetic Resonance Imaging methods, Prostheses and Implants, Prosthesis Design, Tomography, X-Ray Computed methods, Computer-Aided Design, Craniofacial Abnormalities surgery, Image Processing, Computer-Assisted, and Models, Anatomic

The authors describe the main techniques for rapid prototyping used in the medical field, with particular emphasis on Laser stereolithography. They describe the basics of the technique as well as the procedures they currently use to construct anatomic specimens from scanned images. For more than 10 years, the targets of researchers in the field of bone reconstruction in craniofacial surgery have been: to design a system to acquire data directly from CT-scans, to optimize modelling, processing and materials, to verify the possibility of producing prefabricated prostheses with data from preoperative models (22 cases). The target of integrating this technique into therapeutic protocols has been reached. The current trend in research is to produce prostheses from biocompatible materials directly from CT scan data by Laser stereolithography.

Humans, New York, Organizational Objectives, Patient Satisfaction, Multi-Institutional Systems organization administration, Organizational Innovation, and Practice Management, Medical organization administration

Adult, Cerebral Angiography, Female, Humans, Intracranial Aneurysm pathology, Intracranial Aneurysm surgery, Intracranial Arteriovenous Malformations surgery, Magnetic Resonance Angiography, Male, Middle Aged, Tomography, X-Ray Computed, Cerebrovascular Circulation, Intracranial Aneurysm diagnosis, Intracranial Arteriovenous Malformations diagnosis, and Models, Cardiovascular

Background: Recently computed tomographic angiography (CTA) and MR angiography (MRA) have been used to image cerebrovascular structures. Although CTA and MRA are accurate and sensitive imaging modalities, limitations have been identified in relation to image interpretation. Stereolithographic (SL) biomodelling is a new technology that allows three-dimensional (3D) CT and MR data to be used to accurately manufacture solid plastic replicas of anatomical structures. A prospective trial of SL biomodelling in cerebrovascular surgery has been performed to investigate the feasibility and clinical utility of this new display medium.
Methods: Fifteen patients with cerebral aneurysms and 1 patient with a cerebral arteriovenous malformation (AVM) were selected. 3D CT and/or MR angiograms were acquired and 19 solid anatomical biomodels manufactured using the rapid prototyping technology of stereolithography. The biomodels were used for patient education, diagnosis, operative planning and surgical navigation.
Results: The biomodels replicated the CTA and MRA source data. The accuracy of one biomodel was verified by comparison with a post mortem specimen, which corresponded exactly in the x and y planes but differed by 2 mm in the z plane. The ability to closely study an overview of complex cerebrovascular anatomy from any perspective on a solid biomodel was reported to enhance the surgeon's understanding, particularly when conventional images were equivocal. Cerebrovascular biomodels were found to be useful when positioning the patient's head for surgery, for selecting the best aneurysm clip and for the simulation of clipping. Patient informed consent was anecdotally improved. Disadvantages of the technology were the cost and manufacturing time.
Conclusions: Cerebrovascular biomodelling may have utility in complex cases or when the standard imaging is felt to be equivocal.

Calculation of return on investment should be as easy as knowing the cost and the benefit and doing the math. Unfortunately in medical informatics rarely do we know the benefit with absolute certainty. Often the benefit is a combination of "fuzzy" ill defined concepts. In order to support the ROI analysis for medical information systems we developed a probabilistic time varying model that allows each of the fuzzy concepts of savings to be expressed as a likelihood distribution rather than a fixed value. The model and an interactive simulator were created using the graphical programming language G (National Instruments, Dallas,TX). This tools allows rapid prototyping and drag and drop ease of customizing the model to the particular clinical setting. The resulting ROI is expressed in terms of likelihoods, potential risk and confidence intervals providing a unique view of the financial analysis not typically available. In this paper an example is illustrated for perioperative information systems.

Animals, Humans, Chemistry Techniques, Analytical methods, Dimethylpolysiloxanes, Equipment and Supplies, and Silicones

Microfluidic devices are finding increasing application as analytical systems, biomedical devices, tools for chemistry and biochemistry, and systems for fundamental research. Conventional methods of fabricating microfluidic devices have centered on etching in glass and silicon. Fabrication of microfluidic devices in poly(dimethylsiloxane) (PDMS) by soft lithography provides faster, less expensive routes than these conventional methods to devices that handle aqueous solutions. These soft-lithographic methods are based on rapid prototyping and replica molding and are more accessible to chemists and biologists working under benchtop conditions than are the microelectronics-derived methods because, in soft lithography, devices do not need to be fabricated in a cleanroom. This paper describes devices fabricated in PDMS for separations, patterning of biological and nonbiological material, and components for integrated systems.

Humans, Lasers, Microscopy, Electron, Scanning, Biocompatible Materials, and Polyethylenes

Rapid prototyping is a relatively new technology, which although prominent in the engineering industry is only just starting to make an impact in the medical field. Its current medical uses are mainly confined to surgical planning and teaching, but the technology also has the potential to allow for patient-tailored prostheses. The work reported here describes the application of a simplified selective laser sintering apparatus with ultra high molecular weight polyethylene (UHMWPE). The morphology and chemistry of the starting powders and lased material have been characterized using Fourier Transform Infra Red spectroscopy and a combination of light and scanning electron microscopy. It was found that solid linear continuous bodies could be formed, but material shrinkage caused problems when trying to form sheet-like structures. The porosity of the formed material was also a concern. The material exposed to the laser beam was shown to have undergone degradation in terms of chain scission, cross-linking, and oxidation. It has been concluded that to apply this technology to the fabrication of UHMWPE devices requires the development of improved starting powders, in particular with increased density.
(Copyright 2000 John Wiley & Sons, Inc.)