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PubMedDate not supplied

Choice and explanation in medical management: a multiattribute model of artificial intelligence approaches.

This paper explores a model of choice and explanation in medical management and makes clear its advantages and limitations. The model is based on multiattribute decision making (MADM) and consists of four distinct strategies for choice and explanation, plus combinations of these four. Each strategy is a restricted form of the general MADM approach, and each makes restrictive assumptions about the nature of the domain. The advantage of tailoring a restricted form of a general technique to a particular domain is that such efforts may better capture the character of the domain and allow choice and explanation to be more naturally modelled. The uses of the strategies for both choice and explanation are illustrated with analyses of several existing medical management artificial intelligence (AI) systems, and also with examples from the management of primary breast cancer. Using the model it is possible to identify common underlying features of these AI systems, since each employs portions of this model in different ways. Thus the model enables better understanding and characterization of the seemingly ad hoc decision making of previous systems.

Algorithms↗
PubMed2003

A knowledge-based approach to the deflocculation problem: integrating on-line, off-line, and heuristic information.

A knowledge-based approach for the supervision of the deflocculation problem in activated sludge processes was considered and successfully applied to a full-scale plant. To do that, a methodology that integrates on-line, off-line and heuristic information has been proposed. This methodology consists of three steps: (i). development of a decision tree (which involves knowledge acquisition and representation); (ii). implementation into a rule-based system; and (iii). validation. The set of symptoms most useful in diagnosing the deflocculation problem has been identified, the different branches to diagnose pin-point floc and dispersed growth have been built (using generic and specific knowledge), and all this knowledge has been codified into an object-oriented shell. The results obtained in the application of this knowledge-based approach to the Granollers WWTP (which treats about 130000 inhabitants-equivalents) showed that the system was able to identify correctly the problem with reasonable accuracy. Our positive experience building this system suggests that this approach is a practical and valuable element to include in an intelligent supervisory system combining numerical and reasoning techniques.

Artificial Intelligence↗
PubMed1993

An intelligent and cost-effective computer dosing system for individualizing FK506 therapy in transplantation and autoimmune disorders.

The accuracy and precision of an intelligent dosing system (IDS) for FK506 in predicting doses to achieve target drug levels has been prospectively evaluated in transplant and autoimmune patients. For dose individualization, the knowledge base is updated with patient-specific feedback including the current dose, drug level, and the new target level. The study population of 147 patients consisted of 97 transplant patients (liver and kidney) and 50 patients with autoimmune disorders. Patients in the transplant study group were entered sequentially and followed as a cohort. Patients in the autoimmune study group were randomly assigned to one of three predefined FK506 concentration windows (low, 0.1-.3; medium, 0.4-.7; and high, 0.8-1.3 ng/mL) as part of a concentration controlled clinical trial. Predictions of steady-state plasma drug levels were made throughout the clinical course of autoimmune patients and during the first 6 weeks post-transplant in liver and kidney recipients. FK506 concentration in plasma was measured by a monoclonal antibody based ELISA assay. Accuracy was computed as the mean prediction error (mpe). Precision was computed as the root mean squared prediction error (rmspe). The accuracy of the IDS in each study group was as follows: 0.016 ng/mL (liver), -0.034 ng/mL (kidney), and -0.022 ng/mL (autoimmune). Because the 95% confidence interval included zero in each case, the IDS showed no bias. The precision of the IDS in each study group was as follows: 0.133 ng mL (liver), 0.1903 ng/mL (kidney), and 0.1188 ng/mL (autoimmune). These results indicate that the FK506 IDS is both accurate and very precise (reproducible) in transplant and autoimmune patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2006

Obesity and ADHD may represent different manifestations of a common environmental oversampling syndrome: a model for revealing mechanistic overlap among cognitive, metabolic, and inflammatory disorders.

Obesity and attention-deficit hyperactivity disorder (ADHD) are both increasing in prevalence. Childhood exposure to television has shown linkage to both ADHD and obesity with the former ascribed to dysfunctional cognitive hyperstimulation and the latter to altered patterns of diet and exercise. Empirical evidence has contradicted prior presumptions that the hyperactivity of ADHD would decrease the risk of obesity. Instead, obesity and ADHD demonstrate significant comorbidity. We propose that obesity and ADHD represent different manifestations of the same underlying dysfunction, a phenomenon we term environmental oversampling syndrome. Oversupply of information in the form of nutritional content and sensory content may independently predispose to both obesity and ADHD. Moreover, the pathogenic mechanisms of these conditions may overlap such that nutritional excess contributes to ADHD and cognitive hyperstimulation contributes to obesity. The overlapping effects of medications provide further evidence towards the existence of shared etiologic pathways. Metabolism and cognition may represent parallel systems of intelligence, and oversampling of content may constitute the source of parallel dysfunctions. The emerging association between psychiatric and metabolic disorders suggests a fundamental biologic link between these two systems. In addition, the immune system may represent yet another form of intelligence. The designation of syndrome X subsumes seemingly unrelated metabolic and inflammatory entities. Environmental oversampling syndrome may represent an even more inclusive concept that encompasses various metabolic, inflammatory, and behavioral conditions. Apparently disparate conditions such as insulin resistance, diabetes, hypertension, syndrome X, obesity, ADHD, depression, psychosis, sleep apnea, inflammation, autism, and schizophrenia may operate through common pathways, and treatments used exclusively for one of these conditions may prove beneficial for the others.

Attention Deficit Disorder with Hyperactivity↗
PubMed2005

Hypertension and hypothalamo-pituitary-adrenal axis hyperactivity affect frontal lobe integrity.

Chronically elevated cortisol levels have been associated with elevated blood pressure, brain atrophy, and cognitive impairments. In this cross-sectional exploratory study, we assessed whether hypertension was related to hypothalamo-pituitary-adrenal axis hyperactivity and whether this may in part explain prefrontal brain atrophy and cognitive impairments in this population. We studied 27 patients with hypertension and 27 normotensive control subjects. Glucocorticoid feedback was assessed using the combined dexamethasone-CRH test. All participants completed a neuropsychological battery and received brain magnetic resonance imaging for volumetric measurement of frontal and medial temporal lobe regions. Hypertension was significantly associated with impaired glucocorticoid feedback control after statistically controlling for age, gender, and body mass index (P = 0.01). Hypertensive patients also showed a trend toward reductions in frontal lobe volume (P = 0.09) and had significantly lower scores in one of two tests of executive function (P = 0.03). Significant correlations were observed between hypothalamo-pituitary-adrenal hyperactivity and frontal lobe atrophy. Our data indicate that impaired glucocorticoid feedback control may partly account for the prefrontal volume reductions present in patients with hypertension. Future studies assessing the impact of hypertension on the brain should include cortisol assessments.

Adrenocorticotropic Hormone↗
PubMed2001

A computer-aided diagnosis system for digital mammograms based on fuzzy-neural and feature extraction techniques.

An intelligent computer-aided diagnosis system can be very helpful for radiologist in detecting and diagnosing microcalcifications' patterns earlier and faster than typical screening programs. In this paper, we present a system based on fuzzy-neural and feature extraction techniques for detecting and diagnosing microcalcifications' patterns in digital mammograms. We have investigated and analyzed a number of feature extraction techniques and found that a combination of three features, such as entropy, standard deviation, and number of pixels, is the best combination to distinguish a benign microcalcification pattern from one that is malignant. A fuzzy technique in conjunction with three features was used to detect a microcalcification pattern and a neural network to classify it into benign/malignant. The system was developed on a Windows platform. It is an easy to use intelligent system that gives the user options to diagnose, detect, enlarge, zoom, and measure distances of areas in digital mammograms.

Breast Neoplasms↗
PubMed1994

Use of artificial intelligence to analyze clinical database reduces workload on surgical house staff.

BACKGROUND: The current quantity and diversity of hospital clinical, laboratory, and pharmacy records have resulted in a glut of information, which can be overwhelming to house staff. This study was performed to measure the impact of artificial intelligence analysis of such data on the junior surgical house staff's workload, time for direct patient care, and quality of life. METHODS: A personal computer was interfaced with the hospital computerized patient data system. Artificial intelligence algorithms were applied to retrieve and condense laboratory values, microbiology reports, and medication orders. Unusual laboratory tests were reported without artificial intelligence filtering. RESULTS: A survey of 23 junior house staff showed a requirement for a total of 30.75 man-hours per day, an average of 184.5 minutes per service twice a day for five surgical services each with an average of 40.7 patients, to manually produce a report in contrast to a total of 3.4 man-hours, an average of 20.5 minutes on the same basis (88.9% reduction, p < 0.001), to computer generate and distribute a similarly useful report. Two thirds of the residents reported an increased ability to perform patient care. CONCLUSIONS: Current medical practice has created an explosion of information, which is a burden for surgical house staff. Artificial intelligence preprocessing of the hospital database information focuses attention, eliminates superfluous data, and significantly reduces surgical house staff clerical work, allowing more time for education, research, and patient care.

Artificial Intelligence↗
PubMed1993

Basics of robotics and manipulators in endoscopic surgery.

The experience with sophisticated remote handling systems for nuclear operations in inaccessible rooms can to a large extent be transferred to the development of robotics and telemanipulators for endoscopic surgery. A telemanipulator system is described consisting of manipulator, endeffector and tools, 3-D video-endoscope, sensors, intelligent control system, modeling and graphic simulation and man-machine interfaces as the main components or subsystems. Such a telemanipulator seems to be medically worthwhile and technically feasible, but needs a lot of effort from different scientific disciplines to become a safe and reliable instrument for future endoscopic surgery.

Computer Simulation↗
PubMed1996

Intelligent fetal heart rate computer systems in intrapartum surveillance.

The intrapartum cardiotocogram has had a disappointing impact on clinical practice. Misinterpretation of the cardiotocogram not only causes an increase in unnecessary intervention but is also implicated in a large proportion of patients with birth asphyxia and avoidable perinatal morbidity. Over the past 10-20 years, groups have attempted to develop computer systems capable of analysing the cardiotocogram but with limited success. The likely explanation is that these conventional systems analyse the cardiotocogram in isolation from clinical factors. More recently, research has focused on the use of artificial intelligence techniques which can assess the whole clinical picture to support clinical decision making during labour. The current literature is reviewed and a system that has been validated by comparison of its performance with 17 experts is described.

Cardiotocography↗
PubMedDate not supplied

Brain-based devices for the study of nervous systems and the development of intelligent machines.

The simultaneous study of brain function at all levels of organization is difficult to undertake with current experimental tools. Present day electrophysiology only allows the recording of at most hundreds of neurons while an animal is performing a behavioral task. Because of this limitation and the sheer complexity of the nervous system, computational modeling has become essential in developing theories of brain function. Accordingly, our group has constructed a series of brain-based devices (BBDs), that is, physical devices with simulated nervous systems that guide behavior, to serve as a heuristic for testing theories of brain function. Unlike animal models, BBDs permit analysis of activity at all levels of the nervous system as the device behaves in its environment. Although the principal focus of developing BBDs has been to test theories of brain function, this type of modeling may also provide a basis for robotic design and practical applications.

Artificial Intelligence↗
PubMed1991

A multimedia Anatomy Browser incorporating a knowledge base and 3D images.

We describe a multimedia program for teaching anatomy. The program, called the Anatomy Browser, displays cross-sectional and topographical images, with outlines around structures and regions of interest. The user may point to these structures and retrieve text descriptions, view symbolic relationships between structures, or view spatial relationships by accessing 3-D graphics animations from videodiscs produced specifically for this program. The software also helps students exercise what they have learned by asking them to identify structures by name and location. The program is implemented in a client-server architecture, with the user interface residing on a Macintosh, while images, data, and a growing symbolic knowledge base of anatomy are stored on a fileserver. This architecture allows us to develop practical tutorial modules that are in current use, while at the same time developing the knowledge base that will lead to more intelligent tutorial systems.

Anatomy↗
PubMed1996

Role of pharmacokinetic-pharmacodynamic principles in rational and cost-effective drug development.

An important goal of drug development is to define dose and concentration-response relationships for new drugs and biologics. Such critical information from controlled clinical trials can provide primary evidence of efficacy and safety and an informative database for devising dosing instructions for clinical use. This article describes applications of pharmacologic principles [pharmacokinetic-pharmacodynamic (PK-PD)] and modeling methods for drugs in which the evaluation process is guided by and/or identifies significant PK and/or PD variability in drug response. In the case of the recently registered immunosuppressive agent, tacrolimus, preclinical PK-PD in model systems can be used to rationally design safe and effective immunomodulatory dosing regimens for phase 1 clinical studies. Furthermore, a study design based on concentration control guided by a novel artificial intelligence modeling system (AIMS) can be efficiently applied to conduct randomized clinical trials in auto-immunity and to implement cost-effective therapeutic drug monitoring of tacrolimus and cyclosporine in clinical transplantation. In the case of a cardioselective beta-adrenergic blocking agent, betaxolol, marketed for essential hypertension, population PD modeling can be shown to be a more efficient method for estimating dose response compared with standard statistical tests. Using a sigmoid Emax PD model, only a fraction (40 of 300) of the randomized patients was needed to demonstrate dose response. Therefore, two methods, i.e., PD modeling of dose response and AIMS-guided dosing, can achieve significant cost benefits for drug developers, patient care, and the health care system.

Artificial Intelligence↗
PubMed2006

Surgical endovascular neuroradiology in the 21st century: what lies ahead?

Few could have imagined the tremendous growth of endovascular surgery over the past 40 years. Endovascular therapy has greatly enhanced the care of the patient in neurosurgery, spine surgery, and head and neck surgery. Progress in technology and techniques continue to push forward the boundaries of what is deemed "treatable," assuming acceptable risk. This article will briefly review the current state of endovascular surgery and speculate about what its role will be in the near and far future. Endovascular therapy provides a minimally invasive approach to the central nervous system and other systems via natural and, at times, highly selective pathways. Maximizing the accessibility of these routes to highly specific regions of the central nervous system provides an elegant and minimalist approach to treating diseases of the central nervous system with almost no "footprints" of ever having accessed the region. In the future, safe, efficient and intelligent delivery systems that may enhance or alter the tissue's response may result in successful treatment of cerebrovascular diseases, as well as other diseases of the craniospinal axis. The growth of nanotechnology, metallurgy, synthetic polymers, imaging, and training will all combine to help grow the technology and the science that is surgical endovascular neuroradiology.

Catheterization↗
PubMed2005

Automated spoken dialogue system for hypertensive patient home management.

Recent advances in automatic speech recognition and related technologies allow computers to carry on conversations by telephone. We developed an intelligent dialogue system that interacts with hypertensive patients to collect data about their health status. Patients thus avoid the inconvenience of traveling for frequent face to face visits to monitor the clinical variables they can easily measure at home; the physician is facilitated in acquiring patient information and cardiovascular risk, which is evaluated from the data according to noted guidelines. Controlled trials to assess the clinical efficacy are under way.

Automation↗
PubMed1995

Chaotic behavior of hemodynamics with ventricular assist system.

In order to analyze hemodynamic parameters during left ventricular assistance as an entity and not as decomposed parts, non-linear mathematical techniques were utilized. Pneumatically actuated ventricular assist systems (VAS) were implanted as left heart bypasses in acute animal experiments, using healthy adult mongrel dogs. By the use of the non-linear mathematical technique, the arterial blood pressure waveform (AP) was embedded into the four-dimensional phase space and projected into the three-dimensional phase space. The Lyapunov numerical method was used as an adjunct to the graphical analysis of the state space. The phase portrait of the attractor showed a complex structure; a three dimensional solid torus with a screw type structure as a part, suggesting deterministic chaos in the AP without left ventricular assistance. Positive lyapunov exponents confirmed the existence of chaos. During counterpulsation mode left ventricular assistance, the phase portrait of the attractor showed a more complex structure, and positive Lyapunov exponents suggested a greater dimensional deterministic chaos. However, non-structured patterns were seen in the phase space during internal mode VAS driving, suggesting the possibility of dissipative dynamics in the four dimensional phase space. These results suggest that the cardiovascular system with counterpulsation mode VAS driving is in a homeochaotic state, which is thought to be a flexible and intelligent control system. And there is greater dimensional complex dynamics in the circulatory regulatory system with VAD during internal mode assistance.

Animals↗
PubMed1988

Knowledge-based educational systems.

In knowledge-based educational systems, the key concept is that information and procedures are represented in the same data structure. These structures can search for each other in flexible and, consequently, very robust ways. At the Air Force Human Resources Laboratory (AFHRL), our researchers are building computer environments that know what they know, know how people can best use them, and know how to draw inferences about their state--self-referential electronic tutors. In September 1986, artificial intelligence researchers participated in AFHRL's Research Planning Forum for Intelligent Tutorial Systems (ITS). This essay reviews the state of the philosophy, art, and science of artificial intelligence (AI) approaches to education. Then it summarizes the research issues which were presented, discussed, and better defined in this Forum--namely the nature and representation of 1) expertise modules, 2) student diagnostic modules, 3) adaptive instructional and curriculum modules, 4) instructional environments, and 5) man-machine interfaces. Advances in artificial intelligence, cognitive science, and instructional discourse have provided a means for investigating human learning, for representing an individual's own "knowledge processing." Research and development in knowledge-based educational systems seems promising, not only for helping people learn how to perform complex tasks, but also for explicitly expressing how people learn to learn. Therefore, would it not be wise to establish a scientific legacy for the development of effective knowledge-based tutorial systems which is informed by the best studies of mind and meaning, language and thought, purpose and paradox?

Artificial Intelligence↗
PubMed1987

Wechsler Intelligence Scale profiles, the cholinergic system, and Alzheimer's disease.

Forty-one patients with putative Alzheimer's Disease (AD) were evaluated to determine the diagnostic utility of a profile of Wechsler Adult Intelligence Scale (WAIS) subtests which has been proposed by Fuld (1984) to identify cholinergic dysfunction. Only nine (21.9%) of these patients had positive Wechsler profiles. Half (n = 21) of the AD patients had been given the WAIS, and the other half (n = 20) the Wechsler Adult Intelligence Scale-Revised (WAIS-R). Positive profiles occurred more often in the AD subgroup given the WAIS-R, but this difference was not statistically significant. Specificity of the formula was evaluated using Wechsler results of 42 older normals and 30 patients who were being evaluated for dementia but who did not have AD. One of the 42 normals (2.4%) and five of the patient controls (16.7%) showed a positive Wechsler profile. Because of the Fuld formula's low sensitivity, a negative Wechsler profile cannot be used to help rule out AD. Although specificity of the formula is high, the diagnostic value of a positive Wechsler profile is modest even under the most favorable AD baserate conditions.

Aged↗