Distributed coordination of emergency medical service for angioplasty patients

In this paper we study the coordination of Emergency Medical Service (EMS) for patients with acute myocardial infarction with ST-segment elevation (STEMI). This is a health problem with high associated mortality. A “golden standard” treatment for STEMI is angioplasty, which requires a catheterization lab and a highly qualified cardiology team. It should be performed as soon as possible since the delay to treatment worsens the patient’s prognosis. The decrease of the delay is achieved by coordination of EMS, which is especially important in the case of multiple simultaneous patients. Nowadays, this process is based on the First-Come-First-Served (FCFS) principle and it heavily depends on human control and phone communication with high proneness to human error and delays. The objective is, therefore, to automate the EMS coordination while minimizing the time from symptom onset to reperfusion and thus to lower the mortality and morbidity resulting from this disease. In this paper, we present a multi-agent decision-support system for the distributed coordination of EMS focusing on urgent out-of-hospital STEMI patients awaiting angioplasty. The system is also applicable to emergency patients of any pathology needing pre-hospital acute medical care and urgent hospital treatment. The assignment of patients to ambulances and angioplasty-enabled hospitals with cardiology teams is performed via a three-level optimization model. At each level, we find a globally efficient solution by a modification of the distributed relaxation method for the assignment problem called the auction algorithm. The efficiency of the proposed model is demonstrated by simulation experiments.     

Identifying the timing and duration of collecting patient priorities in an orthopedic clinic

The patient‐centered care model supports patients actively engaging in their care. Typically this involves collecting patient‐reported outcomes and priorities that may not be part of the routine practice. There is a research gap related to whether there is time available within the routine orthopedic medical practice to collect patient‐centered data for immediate use without delaying the overall clinical processes or influencing patient clinical experiences. A time study was conducted to quantify the current patient processes at an orthopedic clinic, and a statistical simulation model was used to evaluate potential changes in patients’ clinical process if a patient‐centered survey were to be implemented. The proportion of simulated patients who would experience delays due to the survey, the durations of their delays, and the average duration of the patient process delay were recorded at each step in the clinical process. The results are presented in terms of the relationship between the time devoted to collecting data and the impact on the patient experience for various survey durations at various process points. This study demonstrates an approach to evaluate how introducing a patient priorities survey (for collecting both patient‐reported outcomes and priorities), which could be used in the same patient visit, might impact the clinical process and introduce process delays.     

Modified Smith predictor scheme for periodic disturbance reduction in linear delay systems

This paper presents a disturbance reduction scheme for linear systems with time delays. The linear systems in the study are assumed to be nominally stable, minimum phase, and relative degree one systems. The proposed scheme is a combination of Astrom’s modified Smith predictor with a disturbance reduction controller and a grey predictor. Unlike conventional disturbance rejection methods, the scheme proposed in this study does not require the estimation of disturbance frequencies. The grey prediction method is used to approximate the inverse of the time delay and to enhance the robustness of the disturbance reduction scheme against errors in the estimated delay time. The simulation results demonstrate the successful performance of the proposed disturbance reduction method for controlling a linear system with time delays, subjected to both step and periodic disturbances.     

Modified Smith predictor with a robust disturbance reduction scheme for linear systems with small time delays

This paper presents a robust disturbance reduction scheme using an artificial neural network (ANN) for linear systems with small time delays. It is assumed that the nominal linear systems are stable, minimum phase and relative degree one systems. The proposed structure is an integration of a modified Smith predictor and an ANN‐based disturbance reduction scheme. Unlike other disturbance rejection methods, the proposed approach does not require information about unknown load disturbance frequencies. An ANN is used to approximate the unknown load disturbances and to enhance the robustness of the proposed disturbance reduction scheme against modelling errors in the estimated time delay and the process model. Connective weights of the ANN are trained on‐line using a back‐propagation algorithm until uncertainties resulting from unknown load disturbances and modelling errors are minimized. The simulation results show the effectiveness of the presented disturbance reduction scheme for controlling linear delay systems subjected to step or periodic unknown load disturbances.     

Predictive-delay control based on real-time feedback scheduling

Usually in the context of integrated control and real-time scheduling, quality of control improvement is mainly based on the dynamic measurement process and the system task scheduling parameters (i.e., sampling period, execution time). In this paper, a new feedback controller based on delay prediction is proposed to overcome the degradation of quality for multi-controller systems due to scheduling delays. A statistical analysis is performed to highlight the correlation between scheduling artifacts (delays and jitters) and quality of the control. It is stated that the input–output latency has a significant influence on the quality of control. Hence, it is proposed to reduce control impairments by using a prediction of the response time to update the output. A case study consisting of the control of three servo-motors is used to practically illustrate our statement. The consistency and effectiveness of the improvement are checked through the case of the control of three inverted pendulums.     

医院信息系统项目管理的现状与突破

自20世纪90年代以来,我国医院信息系统发展迅速。到目前为止,全国绝大部分医院实现了信息化管理,并且逐步向区域医疗信息资源共享模式迈进。在医院信息化建设进程中,随着信息系统规模日益庞大,信息管理部门对它的驾驭能力捉襟见肘,原有粗放式的管理模式已远不能适应工作需要。有必要重新审视医院信息系统项目管理模式,实现新的突破。本文以医院信息科为视角,探讨将项目管理九大手段运用到医院信息系统项目建设过程中的作用及效果。     

Model predictive control for in situ bioremediation system

This study describes development of a dynamic predictive control system for the in situ bioremediation process. This automated control system not only balances the complex physical, chemical, and biological processes involved in the remediation process, it also minimizes overall cost of the entire remediation process. The control system is on-line, dynamic, and built based on a predictive model. It includes an optimization tool that consists of a simulation model and an optimization function. The numerical simulation model describes the fate and transport of the subsurface contaminants, while the optimization function is a constrained nonlinear function that has been implemented using genetic algorithms. The system was applied to a lab experiment, and tested with data from a real world site. The results indicated that the dynamic, simulation model-based control system can generate an appropriate control strategy and adjust control actions dynamically. This helps to improve efficiencies of the in situ bioremediation process at petroleum-contaminated groundwater systems.     

Event‐triggered predictive control for networked control systems with network‐induced delays and packet dropouts

This paper presents an event‐triggered predictive control approach to stabilize a networked control system subject to network‐induced delays and packet dropouts, for which the states are not measurable. An observer‐based event generator is first designed according to the deviation between the state estimation at the current time and the one at the last trigger time. A predictive control scheme with a selector is then proposed to compensate the effect of network‐induced delays and packet dropouts. Sufficient conditions for stabilization of the networked control system are derived by solving linear matrix inequalities and the corresponding gains of the controller and the observer are obtained. It is shown that the event‐triggered implementation is able to realize reduction in communication and save bandwidth resources of feedback channel networks. A simulation example of an inverted pendulum model illustrates the efficacy of the proposed scheme.     

Performance evaluation of candidate appointment schedules using clearing functions

This study is concerned with the problem of reducing the waiting times of outpatients. Both scheduled patients and walk-ins are included among the outpatients to reflect the typical medical environment in Japan. The consultation time of a hospital is divided into several blocks, and each scheduled patient is given the start time of a block as his or her scheduled time of the consultation as an appointment. It is assumed that all scheduled patients arrive at the hospital at their scheduled times, while walk-ins arrive randomly. A set of candidate appointment schedules is given, and the process of selecting promising schedules in terms of average waiting times is the focus of the work. To support the selection process without conducting a conventional simulation, the notion of a clearing function is adopted to evaluate each candidate schedule. The clearing function of a system gives the expected output or throughput of the system under varying levels of workload of the system. Although it is necessary to conduct exploratory experiments in advance to obtain the clearing function, the expected waiting time can be estimated by simple calculations with the aid of the clearing function. The average waiting times of four schedules in two scenarios are calculated and compared with those obtained from conventional simulations. It is revealed that the proposed procedure based on the clearing function gives acceptable estimated average values.     

Performance model and evaluation on geographic-based routing

In order to improve the inter-domain routing performance as well as its route aggregation, people have proposed to use geographical information to assist the routing system in both addressing architecture and routing mechanisms. Researches on such mechanism focus on reducing the geographical length of the path selected by routing mechanism. However, to the best knowledge of authors, there is no evaluation about how such reduction influences the actual end-to-end data delivery performance. In this paper, a simple model considering both processing and propagation delays is developed and a method to evaluate the performance of a routing mechanism is presented. Also, a heuristic algorithm to optimize routing performance is presented base on the model. After that, the performance of Geographic-Based Routing (GBR), compared to current practice using Border Gateway Protocol (BGP), is evaluated through a simulation using concrete statistical data accordingly. Result shows that GBR did not show performance improvement in most of the time, and current practice can be improved by more than 50% in performance theoretically. It is believed that this is the first work to model and examine the performance of inter-domain routing in the context of actual packet delivery behavior.     

Inpatient diabetes care: complexity,resilience and quality of care

It is estimated that 10–15 % of UK hospital inpatients have diabetes. Poor glycemic control is a care quality problem that has been linked to organizational factors such as inadequate training, inadequate protocols, problems with communication and teamwork, and difficulty coordinating mealtimes. Interventions using specialist diabetes teams have been effective in addressing some of these problems and have led to increased staff and patient self-efficacy and reduced length of stay. The aim of this study was to investigate how inpatient diabetes care is delivered and how resilience is created and/or breaks down, and to identify the implications for quality improvement. In-depth interviews (n = 32) with diabetes specialist and non-specialist staff were conducted in an acute medical admissions environment in an 850-bed teaching hospital. The Critical Decision Method, a content-orientated knowledge elicitation technique, was adapted to guide interview schedules, which explored key decisions, gaps and discontinuities in care and strategies for work system improvement. Care is delivered through the coordination of a multilayered team of different professionals. Specialists provide expertise and problem solving through case-based reasoning using problem-solving skills acquired through past experience. Ward staff focus on processes and immediate patient needs and are more reliant on decision protocols. Gaps in care can occur and result in delays in referring to specialists and clinical inertia. Specialists are a key source of resilience in the system and bridge gaps by acting reactively to problems, proactively monitoring and anticipating problems, providing staff education, and patient support and education. Opportunities for supporting clinicians to bridge gaps in care were identified.     

妇幼专科医院病理信息系统的设计和实施

随着医疗信息化的发展,病理信息化的重要性被人们所认识,对病理科的工作流程、质控环节、病历信息及图像资料进行全面管理,不仅能提高科室管理水平,提升科研能力,减少人为误差,降低误诊风险,而且能与医院电子病历系统共享信息,使病理科能快速调阅病人的临床资料,临床科室也可以及时浏览病理报告,从而为病人的诊断治疗提供更快速、更准确的指导。该文就妇幼专科医院病理信息系统应用于病理科实验室的系统设计和实施情况进行介绍,并对问题进行了探讨。     

医学影像检查相关信息系统建设分析

目的:根据医学影像科相关信息系统的应用情况、探讨如何构建与维护相关信息系统。方法:通过患者在医院影像学检查流程分析得出预约叫号、RIS、PACS、自助打印、云胶片存储系统之间的工作流程和数据交互过程。结果:医学影像科所有信息系统都是围绕RIS做相关的接口设计进行数据交换。结论:RIS与医学影像科其它信息系统、RIS与HIS、HIS与预约叫号系统都需要进行数据交换,了解相关信息系统的数据交换、进行详细的系统功能需求调研与工作流程分析、针对性培养医学影像科信息系统应用维护人员、选择能长期合作的软件服务厂商、制定系统应急预案对医学影像科信息系统的应用与维护意义重大。     

多变量非线性时滞系统的内模控制

本文将单入单出非线性内模控制的设计方法推广到了含多步时滞的多入多出的非线性系统控制器设计中，对于不含纯滞后的过程，所设计的控制器能够实现所期望的常规性能。其中通过非线性滤波器的加入，能够获得当过程和模型存在失配时的鲁棒性，并使控制器结构得以实现。     

A simple receding horizon control for state delayed systems and its stability criterion

In this paper, a simple receding horizon (or model predictive) control for state delayed systems is presented and its solution is given in a closed form by a reduction method. While the control for a time-delay system is usually complex, the proposed controller is simple to construct and therefore can be simply implemented in real applications. To check the closed-loop stability of the proposed controller, a sufficient condition is provided by linear matrix inequalities. In addition, a numerical algorithm is presented for computing the eigenvalues of systems with distributed time delays, which can be used as a necessary and sufficient condition to check closed-loop stability. It is shown by simulation that this simple control can be a stabilizing control for time-delay systems.     

非线性时滞系统基于降阶观测器的反步镇定控制

针对一类状态未知的非线性严格反馈时滞系统, 本文提出了一种基于静态增益函数的输出反馈控制方案. 首先构造了降阶观测器以估计非线性系统的未知状态. 然后在Backstepping设计的每一步定义了具有控制增益函数 的新型Lyapunov-Krasovskii泛函以补偿未知时变时滞, 定义新的选择不唯一的连续控制增益函数以补偿非匹配项 以及Lyapunov-Krasovskii泛函补偿时滞时产生的非负项. 提出了一种无记忆输出反馈控制方案. 理论分析表明: 该 控制方案消除了未知时滞的影响, 保证了闭环系统所有信号的有界性, 并使系统实现渐近稳定. 最后仿真结果验证 了此控制方案的有效性.     

An interactive computer‐based simulation system for endovascular aneurysm repair surgeries

This paper presents an interactive simulation system for surgical procedures of endovascular aneurysm repair. It extracts anatomical structure of clinic interest from patient‐specific X‐ray computed tomography or magnetic resonance imaging data by image segmentation techniques, and then reconstructs surface triangular meshes of these anatomical structures from the volumetric data. The core of the system is an interactive computer‐based simulation module. It consists of a physical modeling unit, a collision detection unit, a visualization unit, and a control unit. The integration of these units together makes it possible for users to interact with the system in real time, performing virtual catheterization, angiography, and stent graft deployment under a user‐specified rendering mode. The prototype system can be used as a cost‐efficient tool for surgical planning with patient‐specific anatomical geometry and for practice of surgical procedures before actual operation. Copyright © 2016 John Wiley & Sons, Ltd.     

A Framework for Improving the Requirements Engineering Process Management

This paper presents a system dynamics model for improving the requirements engineering process management. The paper argues that improving RE process management improves the quality of the specification produced. It uses a simulation modelling approach to capture the complex and dynamic nature of quality and also the cost of resources and time needed to complete the process. Current claims by various researchers and empirical evidence has led to our proposition that “the earlier in the requirements engineering phase that system dynamics simulation modelling is used, the more effective the RE process management is and the better its product quality will be.” In developing such a model, the paper fills an important gap in the RE process management literature and has potential to provide requirement engineers, managers and software development organisations with a model-based process framework to aid quality assessment and improvement. The paper concludes by suggesting that the framework makes a useful contribution both in providing the foundations for theory building in RE process management and quality improvement by aiding shared understanding through learning and training situations. This revised version was published online in August 2006 with corrections to the Cover Date.     

基于多层C／S结构的医疗管理系统的开发与应用

对一个中小型医院的业务流程进行详细的整体分析,并提出解决方案,且着重于系统实现过程,尤其是对护士工作站的基本功能和实现方法加以描述。在整个医疗系统的设计和实现过程中,始终把握＂以患者为中心＂这一基本原则,使其能更有效地发挥作用。实践说明多层C/S结构用于中小型医院的信息管理是有效的。     

Using simulation technique and genetic algorithm to improve the quality care of a hospital emergency department

This report shows how the quality of service at a hospital emergency department (ED) can be improved by utilizing simulation and a genetic algorithm (GA) to appropriately adjust nurses’ schedules without hiring additional staff. The simulation model is developed to cover the complete flow for the patient through the ED. The GA is then applied to find a near-optimal nurse schedule based on minimizing the patients’ queue time. The data for this research was collected from the ED of Show-Chwan Memorial Hospital in Central Taiwan. After computational analysis and comparisons, we found that by making appropriate adjustments to the nurses’ schedules, the patients’ queue time is shortened, thereby raising the quality of patient-care and patient-satisfaction.