Evaluating interactive computer-based scenarios designed for learning medical technology

The use of medical equipment is growing in healthcare, resulting in an increased need for resources to educate users in how to manage the various devices. Learning the practical operation of a device is one thing, but learning how to work with the device in the actual clinical context is more challenging. This paper presents a computer-based simulation prototype for learning medical technology in the context of critical care. Properties from simulation and computer games have been adopted to create a visualization-based, interactive and contextually bound tool for learning. A participatory design process, including three researchers and three practitioners from a clinic for infectious diseases, was adopted to adjust the form and content of the prototype to the needs of the clinical practice and to create a situated learning experience. An evaluation with 18 practitioners showed that practitioners were positive to this type of tool for learning and that it served as a good platform for eliciting and sharing knowledge. Our conclusion is that this type of tools can be a complement to traditional learning resources to situate the learning in a context without requiring advanced technology or being resource-demanding.     

个体化三维数字模型在单纯多发性肾囊肿手术治疗中的应用体会

目的探讨个体化三维数字模型在后腹腔镜下单纯多发性肾囊肿去顶手术治疗中的应用体会。方法选取山西医科大学第一医院泌尿外科2013年9月至2014年2月收治的单纯性多发性肾囊肿患者30例,依据是否术前行个体化三维重建分为两组,每组15例,研究组患者三维建模后,依据模型进行相应的术前规划及术中导航,分别对两组平均手术时间、平均术中出血量、术中并发症发生率及平均住院日进行比较。结果研究组15例患者采用个体化三维数字模型术前规划、术中导航辅助手术治疗,平均手术时间45 min,术中平均出血量22 ml,平均术中并发症发生率6.7%,平均住院日5.0 d;对照组平均手术时间65 min,术中平均出血量50 ml,平均术中并发症发生率26.7%,平均住院日5.2 d。经统计学检验研究组与对照组相比平均手术时间、平均术中出血量差异具有统计学意义(P<0.05),平均术中并发症发生率及平均住院日天数无统计学差异。结论个体化三维数字模型辅助手术治疗收到了较好的临床效果,值得临床推广应用。     

Psychometric testing of the Norwegian version of the questionnaire,Student Satisfaction and Self-Confidence in Learning,used in simulation

Simulation is increasingly being used as an approach to learning in nurse education. There is a need for frameworks and valid evaluation tools to help guide educators in implementing the method. The questionnaire, Student Satisfaction and Self-Confidence in Learning, which consists of two subscales, has been developed by the National League for Nursing in the US for evaluating simulation used in nurse education.The aim of the present study was to test the questionnaire, Student Satisfaction and Self-Confidence in Learning, for psychometric properties in a Norwegian nurse education context.A sample consisting of 130 nursing students participated in a simulation situation, and 123 responded. When the questionnaire was tested in its entirety, psychometric testing conducted with a principal component analysis did not reveal a stable factor solution. The two subscales were then tested separately. The analysis for Satisfaction with Current Learning suggested a one-component solution, thereby explaining 62.8% of the variance, and the internal reliability was 0.84. With regard to Self-Confidence in Learning, no stable solution was achieved, and an alpha value of 0.64 was shown.To further validate the questionnaire, Student Satisfaction and Self-Confidence in Learning, more studies by various nursing programmes in different cultural contexts are recommended.     

基于内部预试验方差及组间差值的样本量调整模拟

目的 通过盲态下内部预试验IPS样本量调整的模拟分析,探索协变量存在前提下有效控制Ⅰ型错误、保证检验效能的合理统计方法.方法 利用蒙特-卡罗法模拟存在协变量时的两阶段自适应设计过程,分别采用协方差分析法和方差分析法分析两阶段数据,采用合并P值法确定检验的最终结果,比较两种方法对Ⅰ型错误、检验效能值的影响.结果 采用方差分析的Ⅰ型错误膨胀较协方差分析要大,检验效能也较协方差分析略低,但是Ⅰ型错误的增大更明显.结论 根据第一阶段的方差和组间均值差调整样本量时,如果存在协变量,应采用协方差分析方法分别分析第一、二阶段的数据,然后采用合并P值法做出统计推断.     

Numerical Model of the Human Cardiovascular System–Korotkoff Sound Simulation

The numerical simulation of the Korotkoff sounds is realized by a 14 segment hemodynamic model of the cardiovascular system developed in the Institute of Thermomechanics, Czech Academy of Sciences. The cardiovascular system is modeled by four segments of the pulsating heart and by 10 vascular segments of pulmonary and systemic circuits connected with the heart in series. To better understand the generation of Korotkoff sounds the systemic arterial flow is studied in detail by a distributed parameter model. The analysis of self-excited oscillations in a collapsible tube (i.e., the systemic artery) is based on a one-dimensional model where the effect of expected flow separation is replaced by the change of viscous friction along the tube.     

Effect of Strength and Timing of Transmembrane Current Pulses on Isolated Ventricular Myocytes

INTRODUCTION: Little is known about how the amplitude and timing of transmembrane current pulses affect transmembrane potential (Vm) and action potential duration (APD) in isolated myocytes. METHODS AND RESULTS: Ten ventricular myocytes were isolated from five rabbit hearts. Each cell was paced at an S1 cycle length of 250 msec, and S2 pulses of 10-msec duration were delivered at various strengths and time intervals. For all S2 strengths (0.2 to 1.5 nA), the magnitude of changes in Vm did not depend on polarity during the plateau, but were larger for depolarizing pulses during phase 3 repolarization. However, the magnitude of changes in APD varied with polarity during the entire action potential for strengths ranging from 0.5 to 1.5 nA. Greater changes in APD occurred for hyperpolarizing pulses during the plateau and depolarizing pulses during phase 3. In addition, we used a cardiac phase variable to quantify the current threshold for regenerative depolarization and repolarization as a function of prestimulus Vm. Regenerative depolarization occurred during phase 3 repolarization, and its current threshold was less than that required for regenerative repolarization that occurred during the plateau. These data were compared to computer simulations in a patch of membrane represented by Luo-Rudy dynamic kinetics, and the results were qualitatively similar, including the higher threshold for regenerative repolarization compared to regenerative depolarization. CONCLUSION: This characterization of the nonlinear response of isolated cells to transmembrane current, including phase resetting, should aid in understanding the mechanisms of defibrillation because shock-induced changes in Vm and APD have been implicated as important factors in determining defibrillation success.     

起搏周期对人体窦房结有效不应期影响的数学模型探讨

食管法研究113例PCL对SNERP的影响。结果显示:随着PCL缩短,SNERP先缓慢缩短,达最小值后缓慢延长,继而进行性延长,两者关系呈二次多项式曲线。3组受检者的PCL/SCL极小点集中在0.90左右,且此点附近SNERP较稳定,易于区分病窦患者与正常人。建议将PCL/SCL=0.90作为测定SNERP的“最适起搏周期”。