Influence of the Compliance of the Pump Housing and Cannulas of a Paracorporeal Pneumatic Ventricular Assist Device on Transient Pressure Characteristics

Abstract: The dependence of transient pressure characteristics of a ventricular assist device (VAD) on the compliance of its housing and cannulas was investigated in a mock circulation. The peak rate of change of pressure ( dP/dt _max) values was greater in the cannulas than other compartments and was associated with valve closure-induced pressure oscillations. When cannula compliance was increased from 0.0057 to 0.0129 cm³/mm Hg, these values decreased by ˜20%, and outflow cannula pressure oscillation frequency decreased from 17.5 Hz by 35%. This trend was also apparent in the inflow. A VAD housing compliance increase from 0.0162 to 0.0483 cm³/mm Hg caused a dP/dt _max decrease of 30% in both the blood chamber and the outflow cannula. The effect of this change on the inflow was weaker implying that housing absorbs the energy associated with outflow deceleration more effectively than the inflow. These findings suggest that increasing VAD housing and cannulas compliance can improve hydrodynamic performance.     

BPX-80离心式血泵中剪切力引发血管性血友病因子机械损伤的评价

目的 对BPX-80离心式血泵中剪切力引起血管性血友病因子（von Willebrand Factor,vWF）的损伤进行评价,判断其是否可以作为vWF损伤研究的参照泵。方法 按照ASTM标准搭建体外溶血测试平台,使用新鲜猪血在此平台对BPX-80离心式血泵进行8 h测试,然后评估每小时血液样本的溶血水平和vWF损伤,并与静态对照组进行比较。结果 在整个实验过程中,BPX-80的溶血指数保持稳定且较低;高分子量vWF多聚体有少量降解,与静置对照组相比无显著性差异;vWF抗原含量无明显变化,与静置对照组趋势基本一致。结论 BPX-80离心式血泵血液相容性良好,可以作为vWF损伤以及溶血评价实验的基准参照泵,从而为新型血泵的设计与优化提供参考。     

椎动脉发育不良的M RA 分型及临床意义

目的：研究椎动脉发育不良的磁共振血管造影分型及临床意义。方法对80例椎动脉发育不良患者的磁共振血管造影检查结果进行分型,分析不同分型与后循环短暂性脑缺血发作及脑梗死的相关性。结果椎动脉发育不良根据磁共振血管造影表现分为Ⅳ型,其中Ⅰ型后循环短暂性脑缺血发作发生率为81．8％、脑梗死发生率为9．1％,Ⅱ型分别为75．0％、17．9％,Ⅲ型分别为62．5％、29．2％,Ⅳ型分别为35．3％、58．8％;不同分型患者后循环短暂性脑缺血发作及脑梗死的发生率比较差异有显著或极显著性（χ2＝33．57、11．21,P＜0．05或0．01）。结论根据磁共振血管造影影像学表现,可将椎动脉发育不良分为Ⅳ型;椎动脉发育不良分型越高,发生脑梗死的概率越高。     

VD方案和VAD方案治疗多发性骨髓瘤的疗效观察和比较

目的 探讨VD方案和VAD方案治疗多发性骨髓瘤的临床疗效和安全性.方法 回顾性分析了2008年6月到2011年6月我院收治的59例多发性骨髓瘤患者的临床资料,根据治疗方案将患者分为VD组(38例)和VAD组(21例),VD组接受硼替佐米联合地塞米松治疗,3周为一个疗程,治疗2个疗程;VAD组接受长春新碱、阿霉素联合地塞米松治疗,4周为一疗程,治疗2个疗程.分别对两组疗效和不良反应进行分析.结果 VD组和VAD组治疗缓解率分别为83.78％和59.09％,VD方案优于VAD方案,差异具有统计学意义(P＜0.05).VD组主要不良反应为血液毒性和周围神经病变,症状较轻微,在停药和对症处理后症状消失或缓解.VAD组主要不良反应为感染、脱发和血液毒性等,其中感染多以3～4度为主.结论 VD方案治疗多发性骨髓瘤疗效优于VAD方案,不良反应轻微,患者可耐受,值得临床推广使用.     

A novel diaphragm-to-housing junction adhesive method: alumina ball milling

An alumina ball milling method was applied to enhance the adhesiveness and smoothness of the diaphragm-to-housing (D-H) junction. The impact produced by the three rotating alumina balls along the meshed junction made the surface of the junction uniform and smooth. The quality of the D-H junction was evaluated by various methods, such as inspection using an optical microscope and a scanning electron microscope, smoothness examination by an atomic force microscope, and measurement of the tensile strength. All the evaluations revealed marked improvements, and the platelet adhesion test revealed that the alumina ball milling method plays an important role in the blood compatibility enhancement of the D-H junction.Part of this paper was presented at the poster session of the ASAIO (2002) meeting