Biomedical subjects
Publications and source records attributed to A Hasman.
This paper presents a method of segmenting the EEG based on the well-known power spectrum analysis. This procedure is applied to the EEG recordings of two normal subjects in order to determine the temporal EEG variability. These results are compared with a more classical approach.
In this paper three different techniques for segmenting EEG's are presented. The principles of these techniques (the Kalman filter approach, the power spectrum analysis and the texture matrix approach) are explained and the results obtained summarised. The segmentation is used in an interactive EEG interpretation system.
A computer-based data retrieval system for clinical research in oncology is described. The system has been designed to enable busy clinicians to retrieve and analyze data directly without major involvement of a computer specialist. The system uses texts similar to those in daily practice. In most situations no code is printed. The other important feature of the system is its ability to analyze clinical data in the form of tables, frequency distribution, etc. It may also furnish actuarial characteristics of the total population or subpopulations. Mathematical functions are calculated easily. Amendments and updating are simple enabling follow-up data to be incorporated. The system is under use for about 2 years and appears to be a versatile tool in the field of clinical research.
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Measurements of gonad doses received by female patients during routine roentgenology are presented. LiF dosemeters were used to measure the exposure doses in the vagina. With the aid of phantom studies, the ovary doses were calculated from the doses determined in patients. Their relationships to skin doses are shown. The results are tabulated. A comparison with results by other authors is given.
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For the measurement of gonadal doses sensitive dosimeters are necessary. Since CaSO4 (Dy) thermoluminescent dosimeters are very sensitive the energy dependence has been measured as compared to LiF in the tube potential region between 50 and 150 kV. Moreover the output of the LiF dosimeters was compared with the results of ionization chamber measurements. Although the energy dependence of CaSO4 (Dy) is well-known the actual dependence on the potential appears to be within +/- 10% for moderately filtered beams in the region from 50 to 150 kV.
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In this paper a tool, MENU, is presented, with which demonstration packages can be easily constructed. The teacher designs the set-up of the package by editing a demonstration specification file, containing both commands to MENU to display frames to the end-user or to execute tasks and the text of the frames. The text contains explanations for the end-user together with the options he can choose. MENU takes care that the corresponding actions are executed. Two image analysis packages, one about CT and one about gated cardiac bloodpool scintigraphy, are presented as examples of the use of MENU. It is concluded, that with MENU (existing) programs can be modeled into packages very easily and efficiently. MENU proves to be a tool that is worthwhile for educational purposes.
In this paper we discuss an approach to classifying evaluative studies of automated information systems in health care. Selected literature (76 studies) is classified according to the type of automated information system (based on relationship to the care process), the study design used, the data collection methods used, the effect(s) measured and the type of evaluation (e.g. cost-benefit analysis). First results show that certain types of automated information systems have not been evaluated much, going by the number of studies selected. Furthermore, it is observed that certain study designs (time-series design), data collection methods (modelling and simulation) and effect measures (job satisfaction) are hardly to be found in the literature. Only 10 of 76 selected studies used a type of evaluation for which both consequences and costs are considered. Detailed investigation of the literature may provide information for the development of a general framework for the evaluation of different types of automated information systems.
This paper describes the design, implementation and evaluation of a prototype protocol processing system (ProtoVIEW). ProtoVIEW provides protocol information for diagnostic and therapeutic purposes. The developed system described here is used as a research instrument to investigate the impact of automated protocols on the medical decision making of physicians. A first evaluation indicates that residents like to use the system and that usage of the system leads to a more uniform working strategy.
Automatic speech recognition has since long been seen as an ideal method for innovation in diagnosis reporting. Speech technology now seems on the verge of introducing (commercially) attractive systems. The selection of a good speech recogniser is only one consideration in system design. Interface aspects, error handling, reporting method and implementation in the daily working routine are interwoven with the selection of an appropriate speech recognition technique, and should therefore be determined first.
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This paper describes how web technology, currently available, can be used to build a fast and easy flexible protocol information system. The interface design and functionalities of the system were based on experiences with a previous version of a protocol information system (ProtoVIEW). A wide range of diagnostic or therapeutic protocols could be retrieved and viewed with ProtoVIEW. The Web-based version contains all functionalities of the non web-based version plus several new functionalities. The web version contains an X-ray viewer and a great deal of interactivity such as validation of electronic patient data forms. The most important additional function is the context sensitive protocol support that may lead to improved protocol adherence. Finally, the web-based version can be accessed from any working place since patient data and protocols are stored centrally.
In this contribution, the role of health informatics in the medical curriculum is discussed. Firstly, trends in healthcare are presented that may have an impact on the use of IT in healthcare and consequently on education. Then, the traditional educational system is discussed and it is argued that the educational system should be changed. The problem-based approach is presented as an example of a new approach. The implications for education and training in health informatics are given. Given the lack of knowledge with respect to the basics of health informatics of both health professionals and students, attention has to be paid to learning materials. Both IT-EDUCTRA and NIGHTINGALE are presented as European projects that focus on education and training.
Recently, studies have shown the benefits of using clinical guidelines in the practice of medicine. There have been numerous efforts to develop clinical decision support systems that support guideline-based care in an automated fashion, covering a wide range of clinical settings and tasks. Despite these efforts, only a few systems progressed beyond the prototype stage and the research laboratory. For guideline-based clinical decision support systems to be successful, a balance must be made between intuitive but imprecise representations usually encountered by most of today's systems and representations that support a strong underlying clinical performance model. The project described in this paper tries to achieve such a balance. It presents the GASTON architecture that contains a set of reusable software components for the application of guidelines, including design-time components to facilitate the guideline authoring process based on guideline representation models along with execution-time components for building decision support systems that incorporate these guidelines. This architecture was used to develop several guideline representation models such as a rule-based representation to model rule-based guidelines and guideline representation models that address more complex tasks. Also, decision support systems that incorporate these models were developed with the architecture. For the representation and application of various classes of guidelines, rules were also viewed as instances of more complex tasks. By identifying similar characteristics of sets of rules, we developed several tasks such as a drug intera ction and drug contraindication task. Based on these models, we have developed and validated guidelines and decision support systems for use in several application domains such as intensive care, family physicians and psychiatry. In order to be able to represent more complex time-oriented plans, new guideline representation models are being developed.