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Modeling a medical environment: an ontology for integrated medical informatics design.

Modern medical environments have seen an increase in technological complexity and pressures of handling more patients with fewer resources, resulting in higher demands on medical practitioners. Medical informatics designers will have to focus on the problem of organizing medical information more effectively to enable practitioners to cope with these challenges. This article addresses this research problem for the particular area of medical problem solving in patient care. First, we describe a traditional modeling approach for medical reasoning used as a basis for developing some decision support systems. We argue these models may be faithful to what is known about biomedical knowledge, but they have limitations for human problem solving, especially in unanticipated situations. Second, we present an ontological framework, known as the abstraction hierarchy (Rasmussen, IEEE Trans. Man. Cybernetics 15 (1985) 234-243), for integrating patient representations that are faithful to existing biomedical knowledge and that are consistent with what is known about human problem solving. Through an example of a critical event in the operating room, we reveal how this framework can support medical problem solving in unanticipated situations. Third, we show how to use these representations as a frame of reference for mapping medical roles, responsibilities, sensors, and controls in an operating room context. Finally, we provide some insight for medical informatics designers in using this framework to design novel training programs and human-computer displays.

Decision Support Techniques↗

Who wrote the book of life? Information and the transformation of molecular biology, 1945-55.

This paper focuses on the opening of a discursive space: the emergence of informational and scriptural representations of life and hereditiy and their self-negating consequences for the construction of biological meaning. It probes the notion of writing and the book of life and shows how molecular biology's claims to a status of language and texuality undermines its own objective of control. These textual significations were historically contingent. The informational representations of heredity and life were not an outcome of the internal cognitive momentum of molecular biology; they were not a logical necessity of the unravelling of the base-pairing of the DNA double-helix. They were transported into molecular biology still within the protein paradigm of the gene in the 1940s and permeated nearly every discipline in the life and social sciences. These information-based models, metaphors, linguistic, and semiotic tools which were central to the formulation of the genetic code were transported into molecular biology from cybernetics, information theory, electronic computing, and control and communication systems--technosciences that were deeply embedded with the military experiences of World War II and the Cold War. The information discourse thus became fixed in molecular biology not because it worked in the narrow epistemic sense (it did not), but because it positioned molecular biology within postwar discourse and culture, perhaps within the transition to a post-modern information-based society.

History, 20th Century↗

From logical neurons to poetic embodiments of mind: Warren S. McCulloch's project in neuroscience.

After more than half a century of eclipse, the mind (in contradistinction to brain and behavior) emerged in the 1950s as a legitimate object of experimental and quantitative research in natural science. This paper argues that the neural nets project of Warren S. McCulloch, in frequent collaboration with Walter Pitts, spearheaded this cognitivist turn in the 1940s. Viewing the project as a spiritual and poetic quest for the transcendental logos, as well as culturally situated epistemology, the paper focuses on McCulloch's and Pitts' efforts of logical modeling of the mind and on the social conditions that shaped that mission. From McCulloch's "experimental epistemology," the mind - purposes that ideas - emerged out of the regularities of neuronal interactions, or nets. That science of mind thus became a science of signals based on binary logic with clearly defined units of perception and precise rules of formation and transformation for representing mental states. Aimed at bridging the gulf between body and mind (matter and form) and the technical gulf between things man-made and things begotten, neural nets also laid the foundation for the field of artificial intelligence. Thus this paper also situates McCulloch;'s work within a larger historical trend, when cybernetics, information theory, systems theories, and electronic computers were coalescing into a new science of communication and control with enormous potential for industrial automation and military power in the Cold War era. McCulloch's modeling the mind as a system of command and control contributed to the actualization of this potential.

Brain↗

Mathematical modeling and analysis in biochemical engineering: past accomplishments and future opportunities.

This is a personal commentary on the history and future prospects of mathematical modeling and analysis in biochemical engineering. Major transitions in these fields were driven by the appearance of the Aiba, Humphrey, and Millis text, Fredrickson's guidance on conceptualizing mathematical representations of cell populations, and Ramkrishna's development of the cybernetic modeling approach. The value of mathematical models to organize data, to consider interactions in complex systems in a rational way, to correct the conventional wisdom, and to understand essential qualitative features of biological systems has been clearly documented in prior research. The impact of this research in biotechnology discovery has so far been limited, but this will change in the future if we are adept in recognizing emerging opportunities and in integrating new concepts and tools into our research. Mathematical structures and methods, allied with extraordinary contemporary computing power, are essential to the emerging field of functional genomics. Important in this quest is a hierarchy of powerful modeling, analysis, and computational tools which can capture essential quantitative features of available experimental data and use these effectively for analysis and design of metabolism.

Animals↗

The quantification of dental plaque using an image analysis system: reliability and validation.

AIM: Established clinical indices used to measure dental plaque have limitations. The aim of this study was to develop and evaluate a new method of quantitative plaque measurement, with increased sensitivity and reproducibility, using a purpose designed image analysis system. METHOD: After plaque disclosure, the patient was positioned in a cephalometric head holder mounted in a custom-built frame with standard lighting and camera position. A 32-bit Digital Camera grabbed the image of the patient's teeth, which was analysed using Adobe Photoshop (V5.02, Adobe Systems Ltd, Europe) and Image Pro Plus software (V4.0, Media Cybernetics, USA). Measurements were made on 120 incisors in 15 patients and reproducibility was assessed using Fliess' Coefficient of Reliability. Sensitivity was assessed by comparison of results of treatment effects from a clinical trial involving 30 patients. Analysis of covariance was used to compare the image analysis system with the Turesky modification of the Quigley and Hein plaque index and the Addy plaque area index. RESULTS: The results were within the 'Excellent Reliability' category, for inter-operator reproducibility and intra-operator repeatability. CONCLUSIONS: This new system provided accurate quantitative measurements of dental plaque and labial tooth surfaces and was shown to have increased sensitivity when compared with the Turesky modification of the Quigley and Hein plaque index and the Addy plaque area index. The stored images can be re-measured for reliability and comparability between studies.

Analysis of Variance↗

On the relationship between self-focused attention and psychological disorder: a critical reappraisal.

A recent review of the literature on the role of self-focused attention in psychological dysfunction (Ingram, 1990) is critically examined. This article (a) reexamines the evidence relevant to Ingram's proposal that self-awareness is a nonspecific factor involved in virtually all forms of psychopathology and argues that this conclusion is not warranted by the existing evidence; (b) takes issue with his premise that the fact that self-awareness is associated with a variety of psychological dysfunctions poses a conceptual dilemma; (c) corrects several important inaccuracies and mischaracterizations in his presentation of Carver and Scheier's (1981) cybernetic control theory and Pyszczynski and Greenberg's (1987) self-regulatory perseveration theory; and (d) critiques the "self-absorption" model that he proposed as an alternative to extant theories and concludes that this conceptualization does not add to the understanding of either self-awareness processes or psychopathology.

Attention↗

Predicting occupational coping responses: the interactive effect of gender and work stressor context.

This study examined whether gender and work stressor context interacted to affect reports of occupational coping strategies. Participants (N=113) were asked to indicate how they would cope with both self-focused (i.e., solitary) and interpersonal (i.e., group) work overload contexts by providing responses to the Cybernetic Coping Scale (J. Edwards & A. J. Baglioni, 1993). Consistent with the hypothesized interaction, male and female participants evidenced similar coping strategies in the self-focused work overload context, whereas female participants showed significantly higher use of coping (T(2)=.08, p<.05) and, in particular, greater emotional-expressive coping (T(2)=.07, p<.01) in the interpersonal work overload context as compared with male participants. Theoretical and practical implications were discussed.

Adaptation, Psychological↗

The differential distribution of acetylated and detyrosinated alpha-tubulin in the microtubular cytoskeleton and primary cilia of hyaline cartilage chondrocytes.

The primary cilium is a ubiquitous cytoplasmic organelle of unknown function. Ultrastructural evidence of primary cilia in chondrocytes, and their colocalisation with the Golgi apparatus, has led to speculation that these structures are functionally linked. To investigate the relationship between these organelles, we examined the molecular anatomy of the microtubular cytoskeleton in the chondrocytes of chick embryo sterna. Thick cryosections were immunolabelled with antibodies directed against acetylated alpha-tubulin (C3B9), detyrosinated alpha-tubulin (ID5) and total alpha-tubulin (TAT), and imaged at high magnification using confocal laser scanning microscopy. Transmission electron microscopy confirmed the ultrastructure of the chondrocyte primary cilium and its structural relationship to the Golgi apparatus. Detyrosinated and acetylated alpha-tubulins were concentrated in the centrioles, centrosome and microtubule organising centre adjacent to the nucleus, with total alpha-tubulin distributed throughout the cytoplasm. ID5 stained the primary cilium at an incidence of 1 per cell, its colocalisation with C3B9 identifying the primary cilium as one of the most stable features of the microtubular cytoskeleton. Primary cilia varied from 1 to 4 microm in length, and 3 patterns of projection into the extracellular matrix were identified; (1) full extension and matrix contact, with minor undulations along the length; (2) partial extension and matrix contact, with a range of bending deflections; (3) cilium reclined against the cell surface with minimal matrix contact. Ultrastructural studies identified direct connections between extracellular collagen fibres and the proteins which decorate ciliary microtubules, suggesting a matrix-cilium-Golgi continuum in hyaline chondrocytes. These results strengthen the hypothesis that the primary cilium acts as a 'cellular cybernetic probe' capable of transducing environmental information from the extracellular matrix, communicating this information to the centrosome. and regulating the exocytosis of Golgi-derived secretory vesicles.

Animals↗

MRI of the brain is safe in patients implanted with the vagus nerve stimulator.

Metallic devices generally represent a contra-indication for MRI scanning. Based on laboratory testing, the neuro cybernetic prosthesis (NCP) is labelled MRI compatible when used with a send and receive head coil. However, there are no published clinical data to support the safety of brain MRI in patients with the NCP. Our objective was to report clinical experience with such a population. We questioned 40 centres that had implanted the NCP system as of 10/1/99. If MRI had been performed on any vagus nerve stimulator patients, we collected information on these patients, the MRI technique used, any events noted during the scan, including both subjective reports (by the patient ), and observable (objective) changes noted by the staff. Twelve centres (30%) responded. Over a time period of 3 years, there were a total of 27 MRI scans performed in 25 patients. All scanners were 1.5 T. A head coil was used in 26 scans, and a body coil in one. The indications for the scans were diverse. Seven were related to the epilepsy, including aetiology or pre-surgical evaluation. Others were unrelated, including brain tumours, cerebral haematoma, vasculitis, headaches, and head trauma. Three scans were performed with the stimulator on, while 24 were performed with the stimulator off. One patient had a mild objective voice change for several minutes. No other objective changes were noted in any of the patients. One 11-year old reported chest pain while experiencing severe claustrophobia. Twenty-five patients denied any discomfort around the lead or the generator. We conclude that this clinical series supports the safety of routine brain MRI using a send and receive head coil in patients implanted with the NCP System.

Adolescent↗

[Concepts of vulnerability of psychiatric diseases].

Despite intensive research in recent decades, the search for the aetiopathogenesis of psychiatric diseases is just as relevant as ever. In recent years, ideas of the aetiopathogenesis of psychotic diseases based on the concept of "vulnerability" in its diverse variations and developments have been gained increasingly ground. The publications of Zubin and associates above all have contributed to a "vulnerability model". According to this descriptive model, schizophrenic disturbances develop as a result of stimuli/irritants or stress factors under modulation of the social and physical environment as well as dependent on the premorbid personality. The increased vulnerability which gives rise to this is perceived as a threshold descensus of the individual towards stimuli/irritants (with a deficit counter--irritants impulses). Apart from that, multi-causality of vulnerability is assumed as the starting point, whereby there is the possibility of several therapy approaches. Moreover, contrary to the prevailing pessimistic view that schizophrenia is a process-type progressive disease, an episodic nature of schizophrenic psychoses is postulated with a prognosis that is indeed positive in the long term. In recent years, although often not explicitly stated, Zubin's concept of vulnerability was also indubitably subjected to various further developments (the vulnerability stress model by Nuechterlein and associates as also the integrative psycho-biological schizophrenia model by Ciompi may serve as examples). Worth mentioning are also various new concepts from system sciences (such as those from cybernetics, synergetics, the chaos theory, the communication theory, structure determinism etc.), which endeavour to clarify the problem of psychosis. The evaluation of central neurophysiological function deviations with schizophrenics and their relations has so far been oriented above all towards the vulnerability model of Zubin and Nuechterlein, which differentiates temporarily relatively stable trait markers with generally unaltered expressivity at the pre-, intra-, and post-psychotic stages as well as episode markers and intermediate markers. However, specific factors contributing to the pathogenesis of schizophrenic disturbances have not as yet been found, in addition, there is still a multitude of methodological problems and distinctive features to fulfill the expectation of a comprehensive concept with which the whole complexity of the occurrence, the progress, and the outcome of psychoses can be explained. Reintroduction of the concept of vulnerability experienced, as Schmidt-Degenhardt put it, "a renaissance in use that appeared almost inflationary and a completely dubious popularisation ... without reference to its historical implications...". Consequently, a critical view of the use of this term would appear to be necessary.

Humans↗

[Amnesia and closed craniocerebral injury. A clinical study of 82 cases].

In this investigation 82 patients with various head traumas are examined with respect to time and duration of retrograde, congrade and anterograde amnesia, especially the dependence of their duration on the severity of trauma. The more severe the trauma, the longer the duration of all forms of amnesia, the retrograde being the shorter whether there is a loss of conscience (congrade amnesia) or not. A tendency of amnesias to shrink could only be examined following mild brain trauma and occurred seldom. Our findings suggest that short amnesias have less tendency to shrink than long ones. The distribution of amnesias support cybernetic memory models. As a consequence of our findings we give recommendations for the clinical evaluation of patients with head-brain trauma.

Adolescent↗

[General system therapy--considerations on a universal therapy theory and its use on psychotherapy practice].

The cybernetic model of interaction of the early system therapy was derived from the concept of feedback mechanisms. It is based upon the assumption that living beings interact with each other as open systems and thereby exchange information. The model can easily be used for the description and explanation of the therapeutic interactions in all schools of psychotherapy, but it is very abstract. In contrast, in the biosystem theory of Maturana living beings as autopoietic systems are operationally and cognitively closed. Exchange of information among them is not possible. Together with the so-called "radical constructivism" this theory has increasingly influenced system therapy over the past ten years and stimulated the development of an alternative model by which the interaction between therapist and client can be described differently and explained in a new way. The model does not only allow the pragmatic integration of all methods of psychotherapy, but also the design of a therapeutic approach including all schools, which is roughly sketched here and called "general system therapy".

Communication↗

[Manual medicine in otorhinolaryngology. Theoretical principles-- clinical practice--principles of therapy and prevention].

Manual medicine or ¿chirotherapy¿ has become a recognized part of medical training in Germany. In the last few decades, research in various fields has shed light on the pathoanatomic and pathophysiologic causes of functional disorders of the cervical vertebral column whose previous management was characterized by treatment of symptoms. The Arthron system provides a cybernetic model in the form of a closed-loop feedback system for visualization and training purposes. A momentary isolated disorder or recurrent exogenous disorders can be represented as reversible processes; the phases of reflex buildup, development of a vicious circle, and/or exhaustion of compensatory processes can be identified and modeled. The Arthron system focuses on neuromuscular dysfunction as the cause of reversible disturbance (and not on joint dysfunction as the did earlier theoretical models). By focussing on the ¿on-target¿ manoevre, chirotherapy aims at resolving joint dysfunction (blocks) and achieve manual and reflex mobilization. Therapy includes medical relaxation of tense musculature and transient interruption of the nerve pathway.

Cervical Vertebrae↗

[Unexpected and undesirable treatment results].

The most frequent causes of unexpected and undesired results of treatment are due to insufficient information of the patient, furthermore, apart from technical deficiencies, to insufficient attention and experience of the physician, and to erroneous evaluation of the situation, especially with measuring out a dose of treatment-"medicus curat". On the other hand "natura sanat" comprises spontaneous healing. It's reactions of adaptation to functional stress are just partially known and, therefore, cannot be controlled safely. With insufficient incorporation of the cybernetic systems of the tissues into our planning of operations counter-reactions have to be expected, resulting in unphysiological, "unsound" operative procedures. They are characterised by relative frequent recurrences. The chances to reduce unexpected and undesired results in the "curative" and "sanative" sector are outlined. The personal experience remains most important.

Adaptation, Physiological↗

Oscillatory brain states and learning: Impact of hippocampal theta-contingent training.

Eyeblink classical conditioning is a relatively simple form of associative learning that has become an invaluable tool in our understanding of the neural mechanisms of learning. When studying rabbits in this paradigm, we observed a dramatic modification of learning rate by conducting training during episodes of either hippocampal theta or hippocampal non-theta activity as determined by on-line slow-wave spectral analysis. Specifically, if animals were given trials only when a computer analysis verified a predominance of slow-wave oscillations at theta frequencies (3-8 Hz), they learned in half as many trials as animals trained during non-theta hippocampal activity (58 vs. 115). This finding provides important evidence from awake, behaving animals that supports recent advances in our knowledge of (i) brain sites and neurobiological mechanisms of learning and memory, specifically hippocampus and theta oscillations, (ii) the biological plausibility of current models of hippocampal function that posit important roles for oscillatory potentials, and (iii) the design of interfaces between biological and cybernetic (electronic) systems that can optimize cognitive processes and performance.

Acoustic Stimulation↗

Intermittent chaos, self-organization, and learning from synchronous synaptic activity in model neuron networks.

Self-organization of frequencies is studied by using model neurons called VCONs (voltage-controlled oscillator neuron models). These models give direct access to frequency information, in contrast to all-or-none neuron models, and they generate voltage spikes that phase-lock to oscillatory stimulation, similar to phase-locking of action potentials to oscillatory voltage stimulation observed in Hodgkin-Huxley preparations of squid axons. The rotation vector method is described and used to study how networks synchronize, even in the presence of noise or when damaged; the entropy of ratios of phases is used to construct an energy function that characterizes organized behavior. Computer simulations show that rotation numbers (output frequency/input frequency) describe both chaotic and nonchaotic behavior. Learning occurs when synaptic connections strengthen in response to stimulation that is synchronous with cell activity. It is shown that intermittent chaotic firing is suppressed and simple stable responses are enhanced by such learning in VCON networks. This analysis provides a rigorous basis for further investigation of the ideas of Wiener [Wiener, N. (1961) Cybernetics (MIT Press, Cambridge, MA), p. 191] on the origin of slow brain waves due to "the pulling together of frequencies."

Action Potentials↗

Growth regulation in X-irradiated mouse skin; the possible role of chalones.

Extracts of hairless mouse skin were tested for their content of epidermal G1 inhibitor and G2 inhibitor at daily intervals after X-irradiation with 4 500 or 2 250 rad. After either dose the skin extracts lacked G1 inhibitory activity on days 5 and 6 respectively after irradiation. This coincided with the time when the epidermal mitotic rate again became normal and started a period of over-shoot. The time interval of 5-6 days corresponds to the turnover time of the differentiating cells in hairless mouse back epidermis. The findings indicate that the proliferating cells in epidermis can respond to changes in local chalone concentration, even after X-irradiation at the tested doses, and that the irradiated epidermal cell population still retains some important properties inherent in a cybernetically regulated system. The local G2-inhibitory activity also varied after irradiation, but these variations could not be directly related to the corresponding mitotic rates.

Animals↗

Quantitative aspects of repair of potentially lethal damage in mammalian cells.

Stationary cultures of Ehrlich ascites tumour cells have been irradiated with X-rays and then immediately or after a time interval trep plated to measure the survival. The increase in survival observed after delayed plating is interpreted as repair of potentially lethal damage. A cybernetic model is used to analyse these data. Three states of damage are assumed for the cells. In state A the cells can grow to macrocolonies, in state B the cells have suffered potentially lethal damage and can grow to macrocolonies only if they are allowed to repair the damage and in state C the cells are lethally damaged. A method of deriving the values of the parameters of the model from the experimental data is given. The dependence of the reaction rate constant of the repair of potentially lethal damage on the dose D is used to derive a possible mechanism for the production of the shoulder in the dose effect curve. Finally this model is compared with other models of radiation action on living cells.

Animals↗