Journal of medical systems [J Med Syst] 1987 Jun; Vol. 11 (2-3), pp. 177-89.
Subjects
Humans, Pedigree, Data Collection, Database Management Systems, Genetic Diseases, Inborn, and Software
Abstract
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.
Computer methods and programs in biomedicine [Comput Methods Programs Biomed] 1987 Nov-Dec; Vol. 25 (3), pp. 259-73.
Subjects
Database Management Systems, Medical Informatics Applications, Programming Languages, Software Design, Information Systems, and Software
Abstract
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.
Computer methods and programs in biomedicine [Comput Methods Programs Biomed] 1987 Nov-Dec; Vol. 25 (3), pp. 275-80.
Subjects
Drug Information Services, Netherlands, Hospital Information Systems, Pharmacy Service, Hospital, and Software
Abstract
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.
Computer methods and programs in biomedicine [Comput Methods Programs Biomed] 1987 Nov-Dec; Vol. 25 (3), pp. 281-6.
Subjects
Evaluation Studies as Topic, Hospital Information Systems, Pharmacy Service, Hospital, Primary Health Care, Software Design, and Software
Abstract
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.
Boon WM, Westerhof HP, Duisterhout JS, and Cromme PV
Computer methods and programs in biomedicine [Comput Methods Programs Biomed] 1987 Nov-Dec; Vol. 25 (3), pp. 287-96.
Subjects
Animals, Cricetinae, Netherlands, Pilot Projects, Software Design, User-Computer Interface, Information Systems, Primary Health Care, and Software
Abstract
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.
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.
Computer methods and programs in biomedicine [Comput Methods Programs Biomed] 1989 Sep; Vol. 30 (1), pp. 59-70.
Subjects
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
Abstract
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.
Computers in healthcare [Comput Healthc] 1989 Nov; Vol. 10 (11), pp. 35-6, 38.
Subjects
Efficiency, Models, Theoretical, Planning Techniques, United States, and Hospital Information Systems
Abstract
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.
Robb RA, Hanson DP, Karwoski RA, Larson AG, Workman EL, and Stacy MC
Computerized medical imaging and graphics : the official journal of the Computerized Medical Imaging Society [Comput Med Imaging Graph] 1989 Nov-Dec; Vol. 13 (6), pp. 433-54.
Subjects
Magnetic Resonance Imaging, Tomography, Emission-Computed, Tomography, X-Ray Computed, Ultrasonography, Image Processing, Computer-Assisted methods, Software, Software Design, and User-Computer Interface
Abstract
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.
Protein engineering [Protein Eng] 1990 Mar; Vol. 3 (4), pp. 235-43.
Subjects
Amino Acid Sequence, Chemical Phenomena, Chemistry, Protein Conformation, Information Systems, and Proteins
Abstract
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.
Hammond JE, Berger RG, Carey TS, Rutledge R, Cleveland TJ, Kichak JP, and Ayscue CF
Proceedings. Symposium on Computer Applications in Medical Care [Proc Annu Symp Comput Appl Med Care] 1991, pp. 970-2.
Subjects
Hospital Information Systems, Microcomputers, North Carolina, Software, Computer Communication Networks, Information Systems, Medical Records Systems, Computerized, and User-Computer Interface
Abstract
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.
Computer methods and programs in biomedicine [Comput Methods Programs Biomed] 1991 Feb-Mar; Vol. 34 (2-3), pp. 81-9.
Subjects
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
Abstract
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.
International journal of bio-medical computing [Int J Biomed Comput] 1991 May-Jun; Vol. 28 (1-2), pp. 101-16.
Subjects
Computer Graphics, Programming Languages, Hospital Information Systems, Medical Records Systems, Computerized, and User-Computer Interface
Abstract
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.
Computer methods and programs in biomedicine [Comput Methods Programs Biomed] 1991 Dec; Vol. 36 (4), pp. 239-51.
Subjects
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
Abstract
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.
Proceedings. Symposium on Computer Applications in Medical Care [Proc Annu Symp Comput Appl Med Care] 1992, pp. 806-7.
Subjects
Drug Prescriptions, Medical Records Systems, Computerized, Nursing, Ambulatory Care, Artificial Intelligence, and Practice Guidelines as Topic
Abstract
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.
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.
Bulletin of the Medical Library Association [Bull Med Libr Assoc] 1992 Jul; Vol. 80 (3), pp. 281-7.
Subjects
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
Abstract
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).
Computer methods and programs in biomedicine [Comput Methods Programs Biomed] 1992 Sep-Oct; Vol. 39 (1-2), pp. 27-34.
Subjects
Clinical Protocols, Semantics, Database Management Systems organization administration, Hospital Information Systems organization administration, Software Design, and User-Computer Interface
Abstract
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".
Proceedings. Symposium on Computer Applications in Medical Care [Proc Annu Symp Comput Appl Med Care] 1993, pp. 79-83.
Subjects
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
Abstract
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.
Proceedings. Symposium on Computer Applications in Medical Care [Proc Annu Symp Comput Appl Med Care] 1993, pp. 107-11.
Subjects
Computer Systems, Humans, Physicians, Hospital Information Systems statistics numerical data, Medical Records Systems, Computerized statistics numerical data, and Software Design
Abstract
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.
Proceedings. Symposium on Computer Applications in Medical Care [Proc Annu Symp Comput Appl Med Care] 1993, pp. 238-42.
Subjects
Humans, Medical Records Systems, Computerized, Microcomputers, Ambulatory Care Information Systems, Family Practice, and User-Computer Interface
Abstract
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.
Marin R, Taboada M, Mira J, Barreiro A, and Otero RP
International journal of bio-medical computing [Int J Biomed Comput] 1993 Jul; Vol. 33 (1), pp. 25-43.
Subjects
Clinical Protocols, Data Display, Database Management Systems, Databases, Factual, Humans, Medical Oncology, Software Design, Computer Graphics, Expert Systems, Neoplasms therapy, and User-Computer Interface
Abstract
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.
Computers in nursing [Comput Nurs] 1993 Nov-Dec; Vol. 11 (6), pp. 291-5.
Subjects
Humans, Patient Care Team, Program Evaluation, Computer Systems, Documentation, and Hospital Information Systems
Abstract
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.
Clinica chimica acta; international journal of clinical chemistry [Clin Chim Acta] 1993 Dec 15; Vol. 222 (1-2), pp. 13-8.
Subjects
Computer Graphics and Clinical Laboratory Information Systems
Abstract
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.
Clinica chimica acta; international journal of clinical chemistry [Clin Chim Acta] 1993 Dec 15; Vol. 222 (1-2), pp. 23-35.
Subjects
Chemistry, Clinical, Critical Care, Humans, and Clinical Laboratory Information Systems
Abstract
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.
Proceedings. Symposium on Computer Applications in Medical Care [Proc Annu Symp Comput Appl Med Care] 1994, pp. 546-50.
Subjects
Computer Systems, Software, and Systems Integration
Abstract
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.
Pham TQ, Young CY, Tang PC, Suermondt HJ, and Annevelink J
Proceedings. Symposium on Computer Applications in Medical Care [Proc Annu Symp Comput Appl Med Care] 1994, pp. 626-30.
Subjects
Ambulatory Care Information Systems, Computer Communication Networks, and Computer Systems
Abstract
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.
International journal of bio-medical computing [Int J Biomed Comput] 1994 Jan; Vol. 34 (1-4), pp. 365-71.
Subjects
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
Abstract
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.
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.
Computers in biology and medicine [Comput Biol Med] 1994 Sep; Vol. 24 (5), pp. 371-5.
Subjects
Decision Support Techniques, Expert Systems, Systems Integration, Artificial Intelligence, Clinical Laboratory Information Systems, Decision Making, Computer-Assisted, Programming Languages, and Reminder Systems
Abstract
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.
Proceedings. Symposium on Computer Applications in Medical Care [Proc Annu Symp Comput Appl Med Care] 1995, pp. 111-5.
Subjects
Computer Security, General Surgery, Humans, Information Systems, User-Computer Interface, Computer Communication Networks, Computer Systems, Data Display, and Medical Records Systems, Computerized
Abstract
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.
Journal of image guided surgery [J Image Guid Surg] 1995; Vol. 1 (1), pp. 12-6.
Subjects
Computer-Assisted Instruction, Education, Medical, General Surgery education, Humans, Computer Simulation, Surgical Procedures, Operative, and Telemedicine
Abstract
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.
Verbeeck R, Michiels J, Nuttin B, Knauth M, Vandermeulen D, Suetens P, Marchal G, and Gybels J
IEEE transactions on medical imaging [IEEE Trans Med Imaging] 1995; Vol. 14 (3), pp. 577-86.
Abstract
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.
Sundaramoorthy G, Hoford JD, Hoffman EA, and Higgins WE
Computerized medical imaging and graphics : the official journal of the Computerized Medical Imaging Society [Comput Med Imaging Graph] 1995 Jan-Feb; Vol. 19 (1), pp. 131-43.
Subjects
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
Abstract
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.
Bosch WR, Low DA, Gerber RL, Michalski JM, Graham MV, Perez CA, Harms WB, and Purdy JA
International journal of radiation oncology, biology, physics [Int J Radiat Oncol Biol Phys] 1995 Jan 01; Vol. 31 (1), pp. 135-42.
Subjects
Hospital Records, Image Processing, Computer-Assisted, Software, and Radiotherapy, Computer-Assisted instrumentation
Abstract
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
Abstract
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.
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 1995 Oct 24; Vol. 92 (22), pp. 9991-8.
Subjects
Automation economics, Costs and Cost Analysis, Humans, Language, United States, Vocabulary, Speech, Speech Perception, Telecommunications trends, Telephone economics, User-Computer Interface, and Voice
Abstract
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.
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.
Computers and biomedical research, an international journal [Comput Biomed Res] 1995 Dec; Vol. 28 (6), pp. 479-99.
Subjects
Computer Security, Equipment Failure, Software, Computer Communication Networks, and Computer Systems
Abstract
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.
Annales de chirurgie plastique et esthetique [Ann Chir Plast Esthet] 1995 Dec; Vol. 40 (6), pp. 666-75.
Subjects
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
Abstract
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.
Proceedings : a conference of the American Medical Informatics Association. AMIA Fall Symposium [Proc AMIA Annu Fall Symp] 1996, pp. 95-9.
Subjects
Software Design, Computer Communication Networks standards, Hospital Information Systems standards, Software standards, and Systems Integration
Abstract
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.
Proceedings : a conference of the American Medical Informatics Association. AMIA Fall Symposium [Proc AMIA Annu Fall Symp] 1996, pp. 309-13.
Subjects
Computer Graphics, Computer Systems, Humans, Hypermedia, Image Processing, Computer-Assisted, User-Computer Interface, Brain Mapping, Computer Communication Networks, and Software
Abstract
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.
Proceedings : a conference of the American Medical Informatics Association. AMIA Fall Symposium [Proc AMIA Annu Fall Symp] 1996, pp. 719-23.
Subjects
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
Abstract
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.
Optics letters [Opt Lett] 1996 Feb 01; Vol. 21 (3), pp. 174-6.
Abstract
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-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.
Computerized medical imaging and graphics : the official journal of the Computerized Medical Imaging Society [Comput Med Imaging Graph] 1996 Jul-Aug; Vol. 20 (4), pp. 259-68.
Subjects
Anatomy, Cross-Sectional, Humans, Quality Control, Software, User-Computer Interface, Computer Communication Networks, Image Processing, Computer-Assisted, and Radiology Information Systems
Abstract
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.
Proceedings : a conference of the American Medical Informatics Association. AMIA Fall Symposium [Proc AMIA Annu Fall Symp] 1997, pp. 764-8.
Subjects
Cholesterol, Guideline Adherence, Humans, Computer Communication Networks, Database Management Systems, Hyperlipidemias therapy, and Practice Guidelines as Topic
Abstract
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.
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.
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.