Introducing expert systems to medical students using esta, Expert System Teaching Aid

Medical students are allocated little curriculum time for exposure to expert systems. ESTA, a computer model of an expert system, was developed to make best use of this time. The nature of the students' interaction with ESTA is described, and their reactions to the expert system concepts and the place of expert systems in medicine are presented. A discussion of these reactions draws some conclusions about teaching expert systems in particular, and computers in general, in the basic medical course.     

Experience with the Berlin Heart Assist Device

Abstract: Different mechanical circulatory support systems (MCSS) have been in clinical use since 1987 to keep patients alive by assisting the heart during cardiac recovery after open heart surgery, myocardial infarction, acute graft failure after heart transplantation, or as a bridge to transplantation in heart transplant candidates. Four different hospitals in Germany used the Berlin Heart Assist Device. Up until 1993, there were 22 patients in the "recovery" group; 4 patients were weaned from the system, and only 1 patient was discharged from the hospital. In 112 patients the Berlin Heart Assist Device was implanted for the purpose of a bridge to transplantation, 68 were transplanted and 46 patients left the hospital. It was concluded that patients may be kept alive with this system for weeks and months after any kind of cardiogenic shock. Complete cardiac recovery may be achieved in patients with early posttransplant graft failure. Reliable prediction of outcome in bridge–to–transplantation patients requires further experience and improvement of system components.     

修正正交分段线性函数及其在线性与时变线性系统中应用

把分段线性函数和斜波脉冲函数进行统一处理，定义成新的函数，使得新的函数既保持了原先两种函数的基本特性，又获得微分和积分递推算法。应用中具有方便，快速计算的优点。     

An alternative method of nitrous oxide delivery into a minimal-flow circle breathing system

We have sought to define a way in which nitrous oxide can be safely and universally used at minimal to low flows by utilising a circle system with a controlled leak provided by a standard gas analyser sampling line and a fresh gas supply of 50% nitrous oxide in oxygen, entering from a trunk interposed between the ventilator and the circle system. Although preliminary calculations suggested that this arrangement was likely to work, it was found that 13 of 23 patients studied prospectively developed an inspired oxygen fraction below 0.3. We conclude that, although this arrangement provides a new means of introducing nitrous oxide into the circle breathing system, it does not appear inherently safer or more convenient than the conventional route.     

基于系统输出分布的智能控制

提出了文题所述的控制策略,依据输出分布曲线的特征变量选取方法和依据该项信息的规则控制系统。仿真研究得到了满意的结果。在一个实验性二元精馏塔上用IBM-PC进行试验亦获成功。本法对具有非线性特性的分布参数对象,较常规控制策略有明显的优越性。     

两种靶控方法输注异丙酚和瑞芬太尼的安全性和有效性比较

目的 比较靶控血浆浓度和效应室浓度输注异丙酚和瑞芬太尼的安全性及有效性。方法 选择44例腹腔镜胆囊切除的病人,年龄18～65岁,ASA Ⅰ～Ⅱ级,随机分为靶控血浆浓度组(P组)和效应室浓度组(E组)。设定异丙酚和瑞芬太尼的靶浓度分别为4 μg/ml和2 ng/ml。观察给药后意识消失时间、血液动力学变化以及听觉诱发电位指数(AAIs)的变化。术中调整两药靶浓度保持AAIS低于20。记录术毕停药后自主呼吸恢复和睁眼时间和AAIs的恢复。结果 E组意识消失的时间[(0.45±0.10)min]明显短于P组;此时两药的用量也明显高于P组。两组均能引起明显的低血压,但降低程度相似,且均未见严重的心血管副作用。AAIs在意识消失时P组为41±22;E组49±16:但插管时均在20以下。术中血液动力学保持较低水平(P<0.01)。两组的插管评分、麻醉质量评分相似。术后自主呼吸恢复时间和睁眼时间两组均无统计学差异。Aldrate评分及手术结束时疼痛评分差异均无显著性。结论靶控血浆和效应室浓度输注均可达到满意的麻醉效果,但靶控效应室诱导时间更短,且无明显心血管副作用。