Academic literature on the topic 'Medical systems'

<p>The mainpart of this thesis is about the developing of a new analysis tool to be used in Zenicor Medical Systems AB ECG-system. The primary task of the system is to simplify the ECG survey for patients who suffers from different kinds of arrythmias, for example heart fibrillation. With this system is it possible for the patients to do their ECG survey by them self at home and then send the signal with their telephone or mobilphone to a server. The equipment used to do the survey is not bigger than you can have it in a pocket and this results in a bigger flexibility for the patient. A doctor can connect to the server and analys the ECG-curve and follow up the patients condition.</p>

This thesis presents novel, robust, analytic and algorithmic methods for calculating Bayesian posterior intervals of receiver operating characteristic (ROC) curves and confusion matrices used for the evaluation of intelligent medical systems tested with small amounts of data. Intelligent medical systems are potentially important in encapsulating rare and valuable medical expertise and making it more widely available. The evaluation of intelligent medical systems must make sure that such systems are safe and cost effective. To ensure systems are safe and perform at expert level they must be tested against human experts. Human experts are rare and busy which often severely restricts the number of test cases that may be used for comparison. The performance of expert human or machine can be represented objectively by ROC curves or confusion matrices. ROC curves and confusion matrices are complex representations and it is sometimes convenient to summarise them as a single value. In the case of ROC curves, this is given as the Area Under the Curve (AUC), and for confusion matrices by kappa, or weighted kappa statistics. While there is extensive literature on the statistics of ROC curves and confusion matrices they are not applicable to the measurement of intelligent systems when tested with small data samples, particularly when the AUC or kappa statistic is high. A fundamental Bayesian study has been carried out, and new methods devised, to provide better statistical measures for ROC curves and confusion matrices at low sample sizes. They enable exact Bayesian posterior intervals to be produced for: (1) the individual points on a ROC curve; (2) comparison between matching points on two uncorrelated curves; . (3) the AUC of a ROC curve, using both parametric and nonparametric assumptions; (4) the parameters of a parametric ROC curve; and (5) the weight of a weighted confusion matrix. These new methods have been implemented in software to provide a powerful and accurate tool for developers and evaluators of intelligent medical systems in particular, and to a much wider audience using ROC curves and confusion matrices in general. This should enhance the ability to prove intelligent medical systems safe and effective and should lead to their widespread deployment. The mathematical and computational methods developed in this thesis should also provide the basis for future research into determination of posterior intervals for other statistics at small sample sizes.

付記する学位プログラム名: デザイン学大学院連携プログラム<br>Kyoto University (京都大学)<br>0048<br>新制・課程博士<br>博士(情報学)<br>甲第22097号<br>情博第707号<br>新制||情||121(附属図書館)<br>京都大学大学院情報学研究科社会情報学専攻<br>(主査)教授 黒田 知宏, 教授 吉川 正俊, 教授 矢守 克也<br>学位規則第4条第1項該当

The goal of this project was to develop a series of nano platforms for single cell analysis and drug delivery. Nanoparticles are a promising option to improve our medical therapies by controlling biodistribution and pharmacokinetics of therapeutics. Nanosystems also offer significant opportunity to improve current imaging modalities. The systems developed during this thesis work can be foundations for developing advanced therapies for obesity and improving our fundamental understandings of single cell behavior. The first of the two systems we attempt to create was a drug delivery system that could selectively target adipose tissue to deliver uncoupling agents and drive browning of adipose tissue and associated weight loss. Protonophores have a history of significant toxic side effects in cardiac and neuronal tissues a recently discovered protonophore, but BAM-15, has been shown to have reduced cytotoxicity. We hypothesized that the altered biodistribution of BAM-15 encapsulated in a nanoparticle could provide systemic weight loss with minimized side effects. The second system developed utilized quantum dots to create a fluorescent barcode that could be repeatedly identified using quantitative fluorescent emission readings. This platform would allow for the tracking of individual cells, allowing repeat interrogation across time and space in complex multicellular environments. Ultimately this work demonstrates the process and complexity involved in developing nanoparticulate systems meant to interact with incredibly complex intracellular environments.

Bibliography: pages 150-158.<br>Health care systems all over the world are in crisis. The presenting symptom is a cost spiral that is out of control. Money supply is finite, and if this problem continues the system will eventually collapse. There are a number of causes associated with the problem that are usually analysed by reduction, an approach based upon an assumption of simple linear causal relations. This study shows the problem to be the dialectic opposite, in other words these problems are all interrelated through complex causal interactions. Therefore, the health care system is a complex social system and solutions to its problems may be found in terms of the interactions in such a system. An investigation into the history of the health care system shows that the system started with a simple one on one interaction between patients and physicians. At the time of its initiation, very little empirical knowledge was available about illness. After the renaissance, this changed dramatically with a subsequent increase in the ability to diagnose, but also in the complexity to treat illness. However, modern beliefs about illness and illness processes do not reflect the complexity of this knowledge. Beliefs about both illness and knowledge contribute to the process of diagnosis (medical decision making, or problem solving). Furthermore, the expectations, wants, and needs of patients and physicians, as well as the decision environment, increases the complexity and difficulty of this decision making process. These decisions initiate treatment processes that are ultimately represented in the health care system as cost. Therefore, the patient-physician system as the simplest initial interaction is an event that ultimately affects cost. This system is not functioning efficiently at present and a system of inquiry that can improve it may make a contribution to an improved system, and therefore a saving in cost. Altering the diagnostic system from a linear into a circular process, in other words into a learning system, improves both decision making and the use of knowledge. However, an inquiring system is needed in addition that can enhance the rigour of this process. Charles West Churchman devoted a large part of his work to knowledge and the way we acquire knowledge, in other words inquiring systems. His belief is that problem solving ought to be approached in a comprehensive way in order to minimise the risk for making incorrect decisions. Furthermore, because decisions are made upon incomplete information, the solutions will be the cause of new problems. Therefore, problem solving is a never ending cycle of learning. In order to have as complete information as possible about the problem, we have to: know the history of the problem, take a broad view that includes the environment of the problem (use a systems approach), and consider all the alternative solutions to the problem. Virtually all of our knowledge is based upon underlying assumptions. In order to test the validity of the knowledge we use for inquiry and decision making, it is important to test the assumptions upon which the knowledge is based. This is valid in regard to empirical knowledge as well. Finally, according to Churchman, decision making has to be ethical. Therefore, we have to do all we can to ensure that the implementation of the decision will improve the situation, not only now, but also in the future. The application of Churchman's approach to the patient-physician interaction, assists in the synthesis of a more comprehensive world view of health care and illness. This study shows that this leads to important changes in the negative interactions identified as contributing to the health care crisis. In terms of Churchman's approach, the role of physicians can be seen as managers of illness. Their purpose is therefore to plan for the improvement of illness (the problem) in an ethical way. Such planning should include the values of patients in deciding upon appropriate treatment. It is the submission of this study that only a methodology that is able to address complex human systems, such as a systems approach, and a comprehensive philosophy of inquiry, such as that of C West Churchman is appropriate to address the current problems of the health care system.

Thesis (Ph. D.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Systems Science and Industrial Engineering, 2009.<br>Includes bibliographical references.