Biomedical subjects

A Hasman

Publications and source records attributed to A Hasman.

At least 127 records · Page 7Linked to original sources

PubMed1994

The application of a factor evaluation system for community nursing in The Netherlands.

In the literature both advantages and disadvantages are mentioned for factor and prototype patient classification systems. In this study a secondary analysis is used to explore the variance which is explained by a prototype and a factor evaluation classification system of the same patients. In the prototype evaluation system, the care types which were applied resulted in heterogeneous visit times. To explore the factor evaluation system, multiple regression analyses were executed with the average visit time per patient as dependent variable and the activities (separate or aggregated per category) as independent variables. Results show that the activities explain the average visiting time per patient better than the developed care types do.

Aged↗

PubMed1994

Recommendations for medical informatics training in The Netherlands.

In this contribution recommendations for education and training in Medical Informatics as they have been formulated end 1987 by the Subcommittee Medical Informatics of the Royal Netherlands Academy of Arts and Sciences are described. The current situation of education and training is presented and compared with the recommendations. It is concluded that not all recommendations have yet been followed up.

Medical Informatics↗

PubMed1993

To test or not to test, that is the question.

This paper describes a system that is used in Maastricht, the Netherlands, to provide general practitioners with feedback about the adequateness of their test requesting behaviour. The system has proven to be effective. Since the screening of test requests and additional patient data is work-intensive a project was started in the framework of the AIM programme OPENLABS to design a computer-based feedback system. In this system the general practitioner sends test requests to the laboratory decision support system by means of electronic data interchange (EDI). The authors were involved in the development of the EDI messages, which are now accepted standards in the Netherlands. The requests are stored in a database that is part of the laboratory decision support system. The other part of the decision support system, an expert system, obtains the request data (including patient data) from the database, screens the requests for adequateness and provides feedback when necessary.

Clinical Laboratory Information Systems↗

PubMed1993

Evaluation of a patient classification system for community health care.

A patient classification system for community health care developed in the Netherlands is described. The system classifies the time nurses devote to the care of patients. Its purpose is to support the nurse in managerial work. The patient care classification system uses three axes to classify the care: the care type, the number of home visits per week and length of service. The patients are scored on these three axes after the first visit to the patient. This system cannot be used to determine staffing needs on a daily basis but is used as an indicator for budgetary and longer term planning purposes. The system was evaluated by 65 nurses on 1000 patients during 3 months. It is concluded that the care type axis provides good information about the activities that have been performed. Another conclusion is that nurses overestimate the number of visits per week to the patients.

Community Health Nursing↗

PubMed1993

Optimal test strategy in the case of two tests and one disease.

Decision-making, especially about test performance, is very complex in nature. Clinical decision analysis can provide tools for doctors which can be used in improving the ordering of laboratory tests. This article describes an approach which is relevant for medical practice and easy to understand, with the goal of obtaining better decisions rather than optimal solutions. The methodology enables a clear understanding of the possibilities and restrictions of test use and needs very little calculation. The cornerstone of the methodology is a graphical representation, by which the benefits of test use are evaluated. Furthermore, a simple algorithm has been developed that can be used to find the optimal solution in the case of two tests. In each step decision rules can be used. In a graphical representation the effect of combining tests can be easily evaluated. If a test combination is chosen one has to decide which sequence is optimal. Finally one has to choose between parallel and series testing. The gain in time of the parallel procedure (and possible gain in effectiveness of treatment) should be compared with the efficiency gain of series testing. The authors conclude that the developed methodology is closer to the intuitive decision-making process than the traditional decision-making techniques and therefore can be used in order to improve the rather intuitive decisions of doctors.

Clinical Laboratory Techniques↗

PubMed1993

Extrapolation of incomplete marker tracks by lower rank approximation.

Motion and deformation of an object such as the heart may be measured by tracking optical or radiopaque markers. In the experimental situation markers may fail to be detected due to occlusion or lack of contrast. As a result a continuous marker track is observed in separated parts, which often cannot be directly identified as corresponding to one marker. This paper presents a method of extrapolating a partly known track by using information provided by the known track part and the available complete tracks of other markers. The extrapolations are obtained by iteratively fitting a lower rank matrix to the set of noisy, incomplete marker tracks. The performance is evaluated with computer-simulated data and data obtained in an animal experiment. In both cases 43% of the available complete tracks were made incomplete by removal of track parts varying in length from 3% up to 44%. For the simulated data comparison of the extrapolations with true signal values results in a root mean square (RMS) error about equal to the noise level. For the animal experiment, when comparing the extrapolations with the measured values, in images of 256 x 256 pixels, the RMS error was found to be +/- 0.5 pixel, which is quite small relative to the total excursion of a marker (20 pixels). Estimation of the missing data by applying BMDPAM (BMDP Statistical Software Inc.) to the same data results in RMS errors which are about twice as high.

Algorithms↗

PubMed1993

Interpretation of low kappa values.

The use of the kappa statistic is commonly accepted as a measure for interobserver variability. However, in some situations, the interpretation of kappa should be handled with care. In this study 21 obstetricians were asked to segment and classify 13 cardiotocographic recordings for the major fetal heart rate (FHR) patterns acceleration, baseline FHR level, deceleration and undefined segments. In two cases the kappa statistic showed a poor group agreement. These low kappa values, however, were mainly due to the high proportion of baseline segments indicated by the referees. This finding will be exemplified by a discussion of one of the cases.

Artifacts↗

PubMed1993

Interobserver variation in the assessment of fetal heart rate recordings.

Electronic fetal heart rate monitoring (EFM) has not fulfilled its expectations. To improve its validity various attempts were made to standardize terminology and assessment of fetal heart rate (FHR) recordings. In a multinational study, 21 experienced obstetricians were asked to segment and classify FHR patterns, recorded in 13 obstetric cases. In addition, the referees were asked to give their interpretation of the FHR pattern, to assess the fetal condition and to propose obstetric management. The kappa statistic showed fair agreement among the obstetricians for the classification of accelerations, baseline segments and decelerations. Poor agreement was found when the referees had to classify baseline variability or the type of deceleration. Also, the clinical assessment of fetal condition and proposals for obstetric management showed poor agreement among the referees. We conclude there is still a lack of unequivocal terminology and definitions in the assessment of FHR recordings.

Cardiotocography↗

PubMed1992

Inter-institutional information exchange in healthcare.

In this paper the results of the standardization efforts and an evaluation study concerning electronic data interchange (EDI) performed by the 31 (Inter Institutional Information exchange)-project are described. In an earlier paper the results of a preliminary study were reported. EDI concerns communication between autonomous information systems and therefore needs standardization of the messages to be exchanged. In the 31-project ten different types of standard messages have been defined. The use of these messages for exchanging information between hospitals, GPs and pharmacies is described. It is concluded that relatively large time savings can be obtained when communicating electronically. It is also concluded that the electronic data interchange between hospitals and GPs can be performed without additional costs. The electronic communication of prescriptions between GPs and pharmacies does raise the costs of communication at the moment. The impact of EDI on the functioning of people in the organizations involved varies widely.

Clinical Pharmacy Information Systems↗

PubMed1991

Evaluation of computerised questionnaires designed for patients referred for gastrointestinal endoscopy.

The aim of this prospective study was to assess the applicability of a computerised medical history system at the open-access endoscopy unit of a University Hospital during routine clinical practice. We studied feasibility, acceptability and reproducibility of computerised questionnaires designed for patients referred for endoscopy of either the upper or lower gastrointestinal (GI) tract, partly in comparison with almost identical paper questionnaires. In the first period of the study 1134 patients were referred of whom 73% answered the paper questionnaire, and during the second period 537 patients were referred of whom 64% answered the computerised questionnaire (P less than 0.001). There was no sex dependency regarding the ability to answer both types of questionnaires. A significant age dependency regarding the ability to answer the paper questionnaires was observed for patients referred for upper and lower GI endoscopy (P less than 0.0001 and P less than 0.0001). Corresponding with this observation, the ability to answer the computerised questionnaires significantly decreased with increasing age for both groups of patients (P less than 0.0001 and P less than 0.0001). The average completion times of both computerised questionnaires, designed for the upper and lower GI tract, were 11 min. The completion times did not depend on sex, but there was a slight positive correlation with age (P less than 0.0001 with multiple R = 0.27 and P = 0.0593 with multiple R = 0.12). Answering our computerised questionnaires was consistently reported to be interesting and easy, and did not last too long according to the respondents. After patients had answered the computerised history system, the insight into their complaints had increased in 40%, and 45% could put their complaints into words more easily. Only 25% of the patients were unable to express all their complaints. A reproducibility of medical history data of 85% was observed between paper and computerised questionnaires. Our computerised questionnaires can provide us with a detailed and uniformly acquired medical history of most patients referred for GI endoscopy. They are well accepted by the patients and can be completed during the normal waiting period. The medical history data obtained with these questionnaires are quite reproducible.

Adult↗

PubMed1991

Education and medical informatics--five years of experience at the University of Limburg.

In this paper the experience of five years of medical informatics education at the university of Limburg is described. The university of Limburg uses the problem-directed educational system. This system is described. The blocks in Medical Informatics are then presented. Then several program packages that were developed by the department of Medical Informatics of this university are described. Finally the assessment by the students of this type of education is given.

Curriculum↗

PubMed1990

Telecommunication in medicine--the 3I project.

Telecommunication in medicine is becoming increasingly important. This contribution describes a national project in the Netherlands aimed at developing standards for electronic messages and evaluation of cost and benefits of electronic data exchange.

Computer Communication Networks↗

PubMed1990

The differential ratio. A method for describing blood flow in renal transplants.

The blood flow in renal transplants can be represented by (1) a K/A ratio, the ratio of the slopes of the ascending part of the renal perfusion curve and the arterial curve, (2) a perfusion index, the ratio of a part of the area under the first-pass arterial curve and renal curve, and (3) a height ratio, the ratio of the height of the renal curve and the arterial curve at the point of time upon which the arterial curve shows its very first maximum. Because it is sometimes rather difficult to find suitable parameters for these three methods, a differential ratio is proposed, the ratio of the maxima of the 1st derivative of the first-pass renal and arterial curve. Good correlation is found between the K/A ratio and the differential ratio as well as between the perfusion index and the height ratio. This implies that the differential ratio could be used instead of the K/A ratio and that the height ratio is a very good alternative for the perfusion index.

Humans↗

PubMed1990

Noise reduction in estimating cardiac deformation from marker tracks.

Deformation of the cardiac wall is measured by using optical or radiopaque markers attached to the wall. When digitized images are used, the accuracy of the measurement of a marker position is limited by pixel resolution and the size of the marker. The spatial accuracy is improved by singular value decomposition (SVD) filtering. This filtering procedure is based on the assumption that displacements of markers are mutually related because they are embedded in a common continuum. In a computer stimulation with 48 markers in 51 video frames, the accuracy of the measurement of a marker position improved from 0.14 to 0.045 (SD) pixel. In an open-chest animal experiment, with markers on the surface of the heart, the deformation patterns were extracted more clearly using SVD filtering, while mutually related high-frequency components were not suppressed. In a 50-frame sequence of 256 X 256 video images of a 45 mm X 35 mm deforming surface with 50 markers of 8 pixels in diameter, the marker position resolution improves from 0.1 to 0.03 (SD) pixel (6 microns). Strain is determined with an accuracy of 0.002 over a distance of 30 pixels (6 mm).

Animals↗

PubMed1989

Description of a blockcourse in medical informatics.

This paper describes a blockcourse in medical informatics. The course is presented to fourth, fifth and sixth year medical students and lasts one week. During the course all aspects of medical informatics are considered. Programming, databases, information systems, signal analysis, pattern recognition, expert systems, etc. are explained. Lectures alternate with hands-on experience. The subjects discussed in the lectures are rehearsed during the practical sessions, so that gaps in the student's knowledge are immediately detected. The blockcourse has been positively rated by the students.

Computer-Assisted Instruction↗

PubMed1988

ADAMO revisited: an interpretative review of a data management system.

In this paper the use for research purposes of an existing data management system, ADAMO (A Database Management system for Oncology), is described. The aim of this paper is to discuss the experiences, obtained with this 'home-made' system and to describe some of the extensions that were recently made. Reasons are presented why the system is still extensively used by clinicians although a number of commercial database management systems is now available on personal computers. These database systems are more flexible than the system described here. It is concluded that it is precisely this flexibility of current systems that prevents an optimal use by busy clinicians. Clinicians need a research system that contains just the functions that they need. These functions have to be available via simple commands, so that no additional programming--even at the high level of a query language--is necessary.

Computer-Assisted Instruction↗

PubMed1987

Medical applications of computers: an overview.

In this review computer applications in medicine are discussed from the point of view of the levels of information processing as suggested by van Bemmel. Applications are presented and research directions indicated. The purpose of this review article is to give an overview of the field of medical informatics. A structural approach is followed in discussing the subjects of communication, databases, complex calculations (including signal analysis and image analysis techniques), pattern recognition and expert systems. The role the computer system plays in relation to the physician is discussed. It is stressed that computers cannot replace the physician, because computer systems use programs, that are of a scientific nature. This means that only certain aspects are taken into account and that one abstracts from individuality. Therefore, computers are unable to give advice about individual patients regarding their future.

Database Management Systems↗

PubMed1987

A research tool for general practitioners.

In this paper a research tool for general practitioners is described, that will be used in a network of community-based primary care practices in order to collect the necessary data for research purpose. The research tool is coupled to a commercial information system for general practitioners. The research tool supports coding strongly. The way in which the research tool is designed is described and examples of the use of windowing techniques are given.

Family Practice↗