This paper reports a study of complex focussing acoustic fields of a convex phased array probe widely used in ultrasonic diagnostic B-scanner. The time delay necessary for electronic focussing and for geometric focuss...This paper reports a study of complex focussing acoustic fields of a convex phased array probe widely used in ultrasonic diagnostic B-scanner. The time delay necessary for electronic focussing and for geometric focussing of complex focussing is given. By means of Helmholtz's integral formula, the expressions of acoustic fields were obtained for the electronic focussing and complex focussing.With Simpson's numerical integral, a great deal of computations was carried out with an 86 / 330 computer. By means of using different parameters, an optimum focal range and beam width of a 4 sequences electronic and complex focussing acoustic system was selected. With an EUB-40 ultrasound diagnostic B-scanner produced by the Hitachi company, the lateral focussing acoustic field and lateral resolution in an echoic tank were photographed by latticing method and the experimental result is consistent with the theory.展开更多
目的评价在“超声诊断学”教学期间应用案例教学法(Case Based Learning,CBL)联合智慧教室的作用,评估对考核成绩构成的影响。方法选取2019年9月—2023年8月福建中医药大学附属第二人民医院医学影像学专业48名本科学生为研究对象,以简...目的评价在“超声诊断学”教学期间应用案例教学法(Case Based Learning,CBL)联合智慧教室的作用,评估对考核成绩构成的影响。方法选取2019年9月—2023年8月福建中医药大学附属第二人民医院医学影像学专业48名本科学生为研究对象,以简单随机法分为两组,对照组(n=24)予以传统教学法,观察组(n=24)则应用CBL案例教学法联合智慧教室,对比两组教学效果。结果观察组带教后理论知识、操作技能成绩均高于对照组,差异有统计学意义(P均<0.05);观察组理论深化、仪器教学、实操教学、诊断技能各项成绩均高于对照组,差异有统计学意义(P均<0.05);观察组教学满意度高于对照组,差异有统计学意义(P<0.05)。结论在“超声诊断学”教学期间应用CBL案例教学法联合智慧教室有利于提升整体教学效率和教学质量,可提高学生学习参与积极性。展开更多
目的运用基于熵权的逼近理想解排序法(Technique for Order Preference by Similarity to Ideal Solution,TOPSIS)对医用超声诊断仪的可靠性进行量化评价,判别其可靠性的优劣情况。方法通过文献分析法与专家咨询法构建医用超声诊断仪的...目的运用基于熵权的逼近理想解排序法(Technique for Order Preference by Similarity to Ideal Solution,TOPSIS)对医用超声诊断仪的可靠性进行量化评价,判别其可靠性的优劣情况。方法通过文献分析法与专家咨询法构建医用超声诊断仪的可靠性评价指标,以某三甲医院A、B、C 3种型号的医用超声诊断仪2020—2021年间的故障维修数据作为数据来源,计算指标初始数据,运用熵权法获取各评价指标权重,采用TOPSIS法计算各台设备和各种型号的相对接近度Ci,获取医用超声诊断仪的可靠性评价结果。结果建立的可靠性评价体系包括5个指标:平均故障间隔时间、平均首次故障前工作时间(Mean Time To First Failure,MTTFF)、平均修复时间、故障率及可用度,指标中权重占比较高的有MTTFF和可用度。A、B、C 3种型号设备的Ci分别为0.51342、0.44859、0.30324。3种型号医用超声诊断仪中A型号可靠性较优,B型号次之,C型号较差,评价结果基本能客观真实反映医用超声诊断仪的可靠性水平。结论基于熵权TOPSIS法的医用超声诊断仪可靠性评价体系具有一定可行性,可操作性强,评价结果可为医用超声诊断仪购置、维护保养等提供决策依据。展开更多
文摘This paper reports a study of complex focussing acoustic fields of a convex phased array probe widely used in ultrasonic diagnostic B-scanner. The time delay necessary for electronic focussing and for geometric focussing of complex focussing is given. By means of Helmholtz's integral formula, the expressions of acoustic fields were obtained for the electronic focussing and complex focussing.With Simpson's numerical integral, a great deal of computations was carried out with an 86 / 330 computer. By means of using different parameters, an optimum focal range and beam width of a 4 sequences electronic and complex focussing acoustic system was selected. With an EUB-40 ultrasound diagnostic B-scanner produced by the Hitachi company, the lateral focussing acoustic field and lateral resolution in an echoic tank were photographed by latticing method and the experimental result is consistent with the theory.
文摘目的评价在“超声诊断学”教学期间应用案例教学法(Case Based Learning,CBL)联合智慧教室的作用,评估对考核成绩构成的影响。方法选取2019年9月—2023年8月福建中医药大学附属第二人民医院医学影像学专业48名本科学生为研究对象,以简单随机法分为两组,对照组(n=24)予以传统教学法,观察组(n=24)则应用CBL案例教学法联合智慧教室,对比两组教学效果。结果观察组带教后理论知识、操作技能成绩均高于对照组,差异有统计学意义(P均<0.05);观察组理论深化、仪器教学、实操教学、诊断技能各项成绩均高于对照组,差异有统计学意义(P均<0.05);观察组教学满意度高于对照组,差异有统计学意义(P<0.05)。结论在“超声诊断学”教学期间应用CBL案例教学法联合智慧教室有利于提升整体教学效率和教学质量,可提高学生学习参与积极性。
文摘目的运用基于熵权的逼近理想解排序法(Technique for Order Preference by Similarity to Ideal Solution,TOPSIS)对医用超声诊断仪的可靠性进行量化评价,判别其可靠性的优劣情况。方法通过文献分析法与专家咨询法构建医用超声诊断仪的可靠性评价指标,以某三甲医院A、B、C 3种型号的医用超声诊断仪2020—2021年间的故障维修数据作为数据来源,计算指标初始数据,运用熵权法获取各评价指标权重,采用TOPSIS法计算各台设备和各种型号的相对接近度Ci,获取医用超声诊断仪的可靠性评价结果。结果建立的可靠性评价体系包括5个指标:平均故障间隔时间、平均首次故障前工作时间(Mean Time To First Failure,MTTFF)、平均修复时间、故障率及可用度,指标中权重占比较高的有MTTFF和可用度。A、B、C 3种型号设备的Ci分别为0.51342、0.44859、0.30324。3种型号医用超声诊断仪中A型号可靠性较优,B型号次之,C型号较差,评价结果基本能客观真实反映医用超声诊断仪的可靠性水平。结论基于熵权TOPSIS法的医用超声诊断仪可靠性评价体系具有一定可行性,可操作性强,评价结果可为医用超声诊断仪购置、维护保养等提供决策依据。