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At least 631 records · Page 35Linked to original sources
PubMed1993

Computational logic: a method for formal analysis of the ICU knowledge base.

The object of clinical computing is to support the making of clinical decisions. This takes place in an integrated context of care that involves processes of three different kinds: (1) the physiologic processes in the patient, (2) the processes of physiologic data as stored in, and moved within, a distributed computing system, and (3) the therapeutic and decision-making processes of the clinical staff. The clinical computing system is complex, and as we press it further to work as a partner in the complete care context, it tends to become unmanageably so. In this article, we try to suggest how one might begin using a formal mathematical theory, called 'computational logic,' to give theoretical analyses that might help one to understand the computing system and thereby to try to increase its ability to meet demands on it, and might help one to understand the care context as a whole. We examine the three levels, one at a time, looking for structural analogies between them, and trying to identify the ways that they are linked together. Computational logic provides us with a common set of notions for doing so.

Artificial Intelligence↗
PubMed1994

A knowledge-based alarm system for monitoring cardiac operated patients--assessment of clinical performance.

An intelligent alarm system for the postoperative monitoring of cardiac surgery patients, which did not require any manual data entries, was tested in two phases. A clinician monitored at bedside the patients' recovery and verified clinically abnormal physiological states. After the first test with ten patients, the system's rulebase was upgraded and then tested with an additional 15 patients. The alarm system employed two PC/ATs and was programmed to give notice of four pathological states (hyperdynamic state, hypovolemic state, hypoventilation and left ventricular failure) at two levels of urgency (alarm and alert levels). The monitoring lasted 5.4 +/- 1.7 hours per patient (mean +/- S.D.), totalling 134.7 hours. The system alarmed 27 times during the first and 73 times during the second phase of the testing. The sensitivity of the alarms was 100% in both phases, and the specificities increased from 20.0% to 73.9% and from 59.1% to 70.0% for the alarms and the alerts, respectively. This computerized decision support system based exclusively on data available in the automatically collected data base had a low false positive rate and gave early warnings about pathological states in the homogeneous group of adult postoperative cardiac patients.

Adult↗
PubMed2004

Real-time identification and archiving of micro-embolic Doppler signals using a knowledge-based DSP system.

Identification of micro-emboli in the cerebral circulation using transcranial Doppler ultrasound provides valuable clinical information, but, currently, embolic signal detection and analysis are significantly limited because they mainly rely on costly off-line analysis by human experts. In this study, a reliable, high-resolution, real-time automated system for the detection and archiving of embolic signals was designed and implemented using expert system theory and modern DSP technology. Preliminary tests were conducted to evaluate the functions and the performance of the system using data from ten carotid endarterectomy patients and two normal volunteers. Using the widely accepted 7 dB threshold for human reliability and a human expert, majority-decision gold standard, the real-time system reached sensitivity and specificity of 93.6% and 99.3%, respectively, which were close to the results obtained by three human experts under ideal laboratory conditions (90.1% and 99.8%, 98.4% and 99.9%, 98.9 and 99.9%). The new system has the potential to be used either as a bedside monitoring and signal acquisition device, or as a laboratory investigation tool.

Endarterectomy, Carotid↗
PubMed2001

A knowledge-based technique for automated detection of ischaemic episodes in long duration electrocardiograms.

A novel method for the detection of ischaemic episodes in long duration ECGs is proposed. It includes noise handling, feature extraction, rule-based beat classification, sliding window classification and ischaemic episode identification, all integrated in a four-stage procedure. It can be executed in real time and is able to provide explanations for the diagnostic decisions obtained. The method was tested on the ESC ST-T database and high scores were obtained for both sensitivity and positive predictive accuracy (93.8% and 78.5% respectively using aggregate gross statistics, and 90.7% and 80.7% using aggregate average statistics).

Electrocardiography↗
PubMed1991

Knowledge-based approach to the management of serious arrhythmia in the CCU.

An expert system (SETA) for the management of patients in the CCU environment has been developed. SETA suggests therapeutic actions for the treatment of serious arrhythmias that complicate the pathophysiological state of patients recovering from acute and suspected myocardial infarction. The prototype begins by reasoning from the arrhythmia, diagnosed from the ECG signal, and progresses through its inference process by considering ECG changes (i.e. heart rate, QRS width), patient clinical data, patient history and therapeutic drug data, to reach the most appropriate actions for each particular patient. The system was implemented on production rules using M1 as a development tool. SETA uses a multiknowledge base (KB) architecture, one for each particular arrhythmia and relevant complication, and a decision board that controls the firing of the KBs and keeps track of patient status through time. The system takes into consideration aspects that are very important for the human expert, e.g. sequence of arrhythmia appearance, drug contraindications and priority in the case of simultaneous arrhythmia. The development of this system has given insight into the management of critical CCU patients, that should influence the specification and design of intelligent instruments for this clinical environment.

Arrhythmias, Cardiac↗
PubMed1996

[Parry-Romberg syndrome. Summary and new knowledge based on an unusual case].

A 52 year old female with Parry-Romberg syndrome presented with gradual atrophy of the subcutaneous fat and muscle on her chest and back. The disease process was limited to the C3 to T2 dermatomes on the right side. In addition, there was muscle atrophy of the right arm and extending down the back to T10, als well as right sided paralysis of the diaphragm. Sympathetic nerve blockage reduced pain and hyperesthesia; no progression was seen over several months using NMR to monitor the patient. The Parry-Romberg syndrome has been defined in many ways; in view of this unusual case, we review the literature, attempting to provide a more accurate case definition.

Adipose Tissue↗
PubMed2004

Computer-assisted detection of pulmonary nodules: performance evaluation of an expert knowledge-based detection system in consensus reading with experienced and inexperienced chest radiologists.

To evaluate the performance of experienced versus inexperienced radiologists in comparison and in consensus with an interactive computer-aided detection (CAD) system for detection of pulmonary nodules. Eighteen consecutive patients (mean age: 62.2 years; range 29-83 years) prospectively underwent routine 16-row multislice computed tomography (MSCT). Four blinded radiologists (experienced: readers 1, 2; inexperienced: readers 3, 4) assessed image data against CAD for pulmonary nodules. Thereafter, consensus readings of readers 1+3, reader 1+CAD and reader 3+CAD were performed. Data were compared against an independent gold standard. Statistical tests used to calculate interobserver agreement, reader performance and nodule size were Kappa, ROC and Mann-Whitney U. CAD and experienced readers outperformed inexperienced readers (Az=0.72, 0.71, 0.73, 0.49 and 0.50 for CAD, readers 1-4, respectively; P<0.05). Performance of reader 1+CAD was superior to single reader and reader 1+3 performances (Az=0.93, 0.72 for reader 1+CAD and reader 1+3 consensus, respectively, P<0.05). Reader 3+CAD did not perform superiorly to experienced readers or CAD (Az=0.79 for reader 3+CAD; P>0.05). Consensus of reader 1+CAD significantly outperformed all other readings, demonstrating a benefit in using CAD as an inexperienced reader replacement. It is questionable whether inexperienced readers can be regarded as adequate for interpretation of pulmonary nodules in consensus with CAD, replacing an experienced radiologist.

Adult↗
PubMed2004

Computer-assisted detection of pulmonary nodules: evaluation of diagnostic performance using an expert knowledge-based detection system with variable reconstruction slice thickness settings.

The purpose of this study was to evaluate the performance of a computer-assisted diagnostic (CAD) tool using various reconstruction slice thicknesses (RST). Image data of 20 patients undergoing multislice CT for pulmonary metastasis were reconstructed at 4.0, 2.0 and 0.75 mm RST and assessed by two blinded radiologists (R1 and R2) and CAD. Data were compared against an independent reference standard. Nodule subgroups (diameter >10, 4-10, <4 mm) were assessed separately. Statistical methods were the ROC analysis and Mann-Whitney U test. CAD was outperformed by readers at 4.0 mm (Az = 0.18, 0.62 and 0.69 for CAD, R1 and R2, respectively; P<0.05), comparable at 2.0 mm (Az = 0.57, 0.70 and 0.69 for CAD, R1 and R2, respectively), and superior using 0.75 mm RST (Az = 0.80, 0.70 and 0.70 and sensitivity = 0.74, 0.53 and 0.53 for CAD, R1 and R2, respectively; P<0.05). Reader performances were significantly enhanced by CAD (Az = 0.93 and 0.95 for R1 + CAD and R2 + CAD, respectively, P<0.05). The CAD advantage was best for nodules <10 mm (detection rates = 93.3, 89.9, 47.9 and 47.9% for R1 + CAD, R2 + CAD, R1 and R2, respectively). CAD using 0.75 mm RST outperformed radiologists in nodules below 10 mm in diameter and should be used to replace a second radiologist. CAD is not recommended for 4.0 mm RST.

Adult↗
PubMed1988

A knowledge-based system for the design of manual materials handling.

The purpose of this paper is to develop and test an expert system for the design of new and existing repetitive manual materials handling (RMMH) tasks. For new jobs, the expert system provides recommendations on the maximum acceptable weight to be handled under a variety of worker and task variables. For existing jobs, the expert system provides possible solutions to the design of RMMH tasks if the weight handled on the job is greater than the recommended one. The expert system was implemented on an IBM PCXT personal computer. Two examples on how to utilise the expert system in designing new and existing jobs are given.

Journal Article↗
PubMed1993

Knowledge based lipid management system for general practitioners.

The aim of this system is to provide computer generated interpretative reports with management advice for General Practitioners (GPs). The lipid domain was chosen because of its importance in preventive medicine. Request forms to elicit extra clinical information were designed and distributed to a group of randomly selected GPs. Interpretation of laboratory and clinical data categorizes patients according to risk of coronary heart disease. The management system is rule based and provides advice on lifestyle modifications, diet and drug intervention. Previous clinical and laboratory results are taken into account in determining a management strategy. To date 435 request forms have been processed: 309 (71%) from first visits and 126 (29%) from follow-up visits. Normal lipid profiles were found in 19% of cases. There was 93% agreement between management advice given by the system and the expert. The system has now been modified and further evaluation is under way.

Artificial Intelligence↗
PubMed1995

Utilization of laboratory resources: developments in knowledge-based ordering systems.

This paper describes two rule based decision support systems. The first system is used to screen incoming test requests for adequacy on the basis of signs and symptoms volunteered by the requesting GPs. The system was tested using a database of 794 requests for a TSH test. About 17% of the test requests were correctly identified as unnecessary. In total, 0.5% of the tests were incorrectly labelled as unnecessary. This concerned 4% of the patients that appeared to have hyperthyroidism and 23% of the patients that appeared to have hypothyroidism on the basis of TSH and FT4 results. The other system is a rule-based clinical decision support system for the requesting of laboratory investigations, originally designed for use at a hospital within the UK, that was implemented in a predominantly French-speaking hospital in Belgium. This involved the modification of the system to allow multilingual operation, and also the implementation of a completely new set of investigation protocols. The purpose of this study was to assess the transferability, both of the system itself, and of its benefits. The system was introduced gradually and has only recently been in full operation. However, the findings from the first months of routine use of the system indicate that the transfer of the system to a different clinical environment has been successful. Although it is too early to assess fully the impact on laboratory utilization, the clinicians believe that it is improving the appropriateness of investigations.

Artificial Intelligence↗
PubMed1984

Development of a nursing knowledge base in the life sciences: problems and prospects.

This paper reviews some of the issues concerning the role of the life sciences in nursing education. The unique contribution of the study of these sciences to the theory and practice of nursing is noted, but it is argued that progress in their application to the developing curriculum of nursing is hampered by the traditional adherence to the medical and biomedical emphasis in schools of nursing. It is suggested that the use of a new concept termed bionursing could provide a basis for the development of a distinctive link between the life sciences and their application to the practice of nursing. The author reports part of a study of the role of the life sciences in nursing which suggests that nurse educators are themselves concerned about the difficulty of linking the study of the life sciences directly to nursing theory and practice.

Curriculum↗
PubMed1995

Towards knowledge-based practice; an evaluation of a method of dissemination.

This paper describes a method for the dissemination of research-based information to nurses. The approach involved the development and evaluation of a clinical information pack relating to the management of leg ulcers. The evaluation incorporated a pre-post test two group experimental design. The sample comprised 171 qualified community nurses working in five health authorities. Data were collected by means of two extensive questionnaires administered to groups of nurses. The study collected large amounts of descriptive data pertaining to nurses' clinical practices in the care of this patient group. It also uncovered important factors, quite independent of leg ulcers, related to relationship between research and clinical practice, and the way information is disseminated to practitioners. These independent findings and their implications are discussed here.

Diffusion of Innovation↗