一种新聚醚砜中空纤维血浆成分分离膜的

血浆成分分离膜在双滤法血浆分离中起重要作用。我们以一种新型聚醚砜中空纤维血浆成分分离膜为考察对象,研究时间、跨膜压(TMP)和平均剪切速率等对筛分系数(SC)的影响。血浆入口流量QI=30ml/min,血浆滤出流量QF=20ml/min时,各种蛋白质的SC在约40min达最大值;而TMP增大,SC有一最大值,QF增大,SC曲线和QF曲线有一交点我们认为是较理想的成分分离条件,一般控制血浆滤过分数PFR=QF/QI=0.6～0.7;平均剪切速率变化,TMP相应变化,但SC变化很小。这些数据对血浆成分分离膜的应用有重要意义。     

一种新聚醚砜中空纤维血浆成分分离膜的筛分特性及影响因素

血浆成分分离膜在双滤法血浆分离中起重要作用。我们以一种新型聚醚砚中空纤维血浆成分分离膜为考察对象，研究时间、跨膜压（TMP）和平均剪切速率等对筛分系数（SC）的影响。血浆入口流量Q1=30ml/min，血浆滤出流量QF=20ml/min时，各种蛋白质的SC的约40min达最大值；而TMP增大，SC有一最大值，QF增大，SC曲线和QF曲线有一交点我们认为是较理想的成分分离条件，一般控制血浆滤过分数PFR=QF/QI=0.6～0.7；平均剪切速率变化，TMP相应变化，但SC变化很小。这些数据对血浆成分分离膜的应用有重要意义。     

双滤法再循环血浆分离中血浆成份分离的筛分系数

治疗血浆分离技术在血液净化中占有重要地位[1,2].双滤法血浆分离(DFPP)是 Agishi等人[3]首先提出并用于临床的,目的是减少或/和避免血浆置换过程中所需要大量的、昂贵的正常血浆或/和血浆替代液(白蛋白溶液),以及传染如肝炎等危险.双滤法再循环血浆分离是为提高有用血浆的回收率,达到提高选择性血浆成份分离的目的 [4].本文旨在讨论双滤法再循环血浆分离过程中,血浆成份分离膜的筛分系数,涉及了浓缩系数,对评价选择性血浆成份分离膜的性能,动物实验和临床应用有参考价值.     

聚醚砜中空纤维膜血浆分离器血浆分离功能与血液相容性的评价

对新型材料聚醚砜制作的中空纤维膜血浆分离器进行动物实验 ,评价了膜对血浆蛋白的分离功能及材料的血液相容性。分离过程中 ,实验动物状况良好 ,无溶血现象发生 ,膜对血浆总蛋白、白蛋白和球蛋白的筛分系数均在 95以上 ,约 6 0的血浆从全血中分离出来。白细胞、血小板和四种凝血因子在分离开始时都有不同程度地减少 ,但均在临床允许的范围内。     

聚醚砜中空纤维膜血浆分离器血浆分离功能与血液相容性 …

对新型材料聚醚砜制作的中空纤维膜血浆分离器进行动物实验，评价了膜对血浆蛋白的分离功能及材料的血液相容性。分离过程中，实验动物状况良好，无溶血现象发生，膜对血浆总蛋白、白蛋白和球蛋白的筛分系数均在９５％以上，约６０％的血浆从全血中分离出来。白细胞、血小板和四种凝血因子在分离开始时都有不同程度地减少，但均在临床允许的范围内。     

中空纤维膜与血浆分离(续)

3.2.2 用图象分析仪测定血浆分离膜的孔径 丛血浆分离膜的SDM照片仅能给出粗略的直观认识,而无法得到这些差异的具体数值。为此,日本的Kigotaka Sakai等人采用图像分析仪对AP-05(或称PF-02),MPC-60TD,P_2及PVA-SA四种血浆分离膜的SEM照片做了进一步分析。发现AP-05H孔径分布范围为680×10~(-10)～6400×10~(-10)m(图19),另外三种膜的孔径范围也几乎和     

国际会议文摘选

具有不同微孔结构和过滤特性的各种类型的膜已用于血液过滤的各个方面,如血浆分离(PS),血浆分级(PF),血液过滤(HF)和血液透析(HD)。通常能透过全部或部分血浆蛋白一类大分子的微孔膜已用由PS和PF;膜表面有一层表皮结构的不对称膜则用于HF;无孔的对称膜用于HD,但这种膜不能透过血浆蛋白。在相同的操作条件下,用这种膜对血液进行了对滤。     

血浆交换与血浆吸附进展

1 技术血浆交换、血浆吸附均属于血液净化技术,最近已广泛用于临床。与其他的血浆净化技术不同,血浆净化不是全血,而是由全血中分离出血浆成分,对血浆进行各种处理,从而弃去病因相关物质。目前临床应用的血浆分离法有采用离心分离器,利用血细胞成分和血浆成分的比重不同将血浆成分分离的方法以及利用滤过膜将有形成分血细胞和液体成分血浆分离的方法。     

测定血浆肿胀压的肿胀仪

1896年Starling首先提出血浆胶体肿胀压(Colloid oncotic Pressure简称COP)对经毛细血管的液体吸收过程的意义。COP的测定对诊断肺水肿病人具有十分重要的意义。在休克时特别是合并有败血症,低血浆肿胀压和毛细血管通透性异常是其重要的特征。病人在治疗期间,如果在肺内渗透的液体静力学压力梯度大于8mmHg,则肺水肿即可避免。目前,COP的测量已很容易。因此,在危重病人的处理中值得大力推广应用。本文介绍一种应用新定标系统的简单肿胀仪,其原理为,丰透膜用来分隔器内的两种不同溶液。一只容器盛有胶体的标准溶液,而另一只容器装满未知肿胀压的血浆。半透膜容许小分子量的物质自由透过,但不能透过大分子量(MW>30,000)的     

缺氧对大鼠肺动脉平滑肌细胞~(45)Ca~(2 )跨膜内流及细胞内钙含量的影响

为探讨缺氧时血管平滑肌细胞的钙动力学改变及其在HPV发生中的意义,我们研究了:(一)肺泡性缺氧对大鼠灌流肺的肺动脉压和肺动脉平滑肌细胞~(45)Ca~(2 )跨膜内流的影响:Wistar大鼠22只,随机分为缺氧组     

基于热流耦合的轴流式血泵温升影响因素研究

人工心脏已进入临床发展阶段，溶血现象是制约人工心脏长久使用的一大难题。不正常的温度条件会使红细胞的正常生理机能和形态发生改变，从而影响其携氧能力。为研究人工心脏正常运转时的温升情况，先利用Solidworks软件建立轴流式血泵的三维仿真模型，然后基于ANSYS Workbench软件对血泵整体进行热流耦合温度场仿真，探究了定子绕组相阻值、血泵转速、定子外壳和泵外壳之间的气隙导热系数以及血液导热系数对血泵及血液整体温升的影响。结果表明，在满足血泵供血要求的前提下，适当减小定子绕组相阻值、降低转速可有效降低血泵整体温升，而气隙物质和血液导热系数的变化对血泵整体温度的影响不是很明显。     

轴流式血泵无位置传感驱动控制系统设计

目的:设计一种无位置传感器轴流式血泵驱动控制系统,实现轴流式血泵的速度闭环控制、无线状态监测及动态调节控制。 方法:以STM32F103作为主控芯片,设计六臂全桥驱动电路,采用端电压过零检测实现转子位置和速度检测,并设计PI控制器实现闭环控制,使用无线蓝牙通讯实现泵状态监测及控制。 结果:驱动控制系统速度响应快,稳态误差小于1%,在8 000 rpm转速下,能够达到人体血液循环所需的流量及压差要求。 结论:系统实现了轴流式血泵无位置传感的启动及速度闭环控制,通过蓝牙模块实现对泵运行过程的电压、电流及流量进行监控和运行过程中根据病人生理情况动态调节泵转速。     

New methods for hemoglobin detection in a microparticle-plasma suspension

In the extracorporeal adsorption system, MDS (Microspheres based Detoxification System), micro-adsorbent particles measuring 1-25 micrometers circulate in a filtrate circuit for highly specific blood purification/adsorption. The MDS circuit containing the adsorbent microparticles is linked to the patient's blood line by a hollow fiber plasma filter. When the transmembrane pressure or the shear forces due to the red blood cells in the hollow fiber filter are too high, they can be damaged and hemoglobin will be released. In order to detect free hemoglobin (fHb) by optical means, we have designed a new flow-dynamic filter system, placed in the microadsorbent circuit for continuous separation of microparticles from the filtrate. In the flow dynamic filter, we use a high velocity liquid vortex to remove sedimentation and particle plugs on the filter membrane. In our investigations, 3 and 8 micron cellulose nitrate filter membranes for particle separation are used. The obtained particle free bypass filtrate flow rates are typically 0.5 and 0.8 ml/min respectively. The typical sensitivity for fHb detection by the applied noninvasive optical method is 0.15 g/dL. Medical safety regulations require a fail-safe mechanism for fHb detection which monitors the bypass filtrate flow in the flowdynamic filter and shuts down the system in case of membrane occlusion. The bypass filtrate flow is monitored by periodically occluding and releasing the bypass line by means of a clamp. The resulting back pressure profile gives information about the actual filtration rate. This safety principle was proven by statistical analysis and shows its clear functionality.     

腹部高能创伤瞬间主动脉内血流动力学变化的模拟实验

为了探讨枪伤远达效应的发生机制，设计了模拟实验，在模拟腹部枪击瞬间用压力传感器测试计算了主动脉内血流动力学的变化。实验结果与显示击瞬间主动脉内压力高，压力上升速度快，血流速度快，压差大，流量大。     

腹部枪伤时颈总动脉内血流动力学变化的模拟实验

为了探讨腹部枪伤时脑损伤的发生机制，本研究设计了模拟实验，在模拟腹部枪伤瞬间用压力传感器测试并计算了模拟总动脉内血流动力学变化。实验结果显示枪击瞬间颈总动脉内压力高，压力上升速度快，血流速度快，压差大，流量大。大量血流从颈总动脉急速涌向脑部必须导致脑部的损伤。     

小转速髓芯减压结合自体红骨髓组织工程复合物治疗早中期股骨头缺血性坏死

目的探讨小转速髓芯减压结合自体红骨髓组织工程复合物治疗早中期股骨头缺血性坏死的临床疗效。方法选取2010年6月至2015年6月在我院住院的股骨头缺血坏死患者47例(52髋),采用随机数字表法分为2组:A组采用小转速髓芯减压+自体红骨髓组织工程复合物的方法治疗25例(28髋),B组采用髓芯减压+人工骨治疗22例(24髋),所有患者术前行髋关节X线片、CT及MRI检查,术后6、12、18个月行髋关节X线片、CT、MRI检查观察股骨头修复及坏死进展情况。结果所有病例平均随访34个月(18~60个月)。经过治疗,两组患者的临床坏死体积对比,影像学稳定率,股骨头生存率,有统计学差异(P0.05),两组患者的性别、年龄、病因基础资料差异无统计学意义(P0.05)。结论小转速髓芯减压+自体红骨髓组织工程复合物治疗早中期股骨头缺血性坏死操作简单,临床疗效满意,早期患者术后优良率更高。     

Acute in vivo evaluation of an implantable continuous flow biventricular assist system

An implantable biventricular assist device offers a considerable opportunity to save the lives of patients with combined irreversible right and left ventricular failure. The purpose of this study was to evaluate the hemodynamic and physiologic performance of the combined implantation of the CorAide left ventricular assist device (LVAD) and the DexAide right ventricular assist device (RVAD). Acute hemodynamic responses were evaluated after simulating seven different physiological conditions in two calves. Evaluation was performed by fixing the speed of one individual pump and increasing the speed of the other. Under all conditions, increased LVAD or RVAD speed resulted in increased pump flow. The predominant pathophysiologic effect of independently varying DexAide and CorAide pump speeds was that the left atrial pressure was very sensitive to increasing RVAD speed above 2,400 rpm, whereas the right atrial pressure demonstrated much less sensitivity to increasing LVAD speed. An increase in aortic pressure and RVAD flow was observed while increasing LVAD speed, especially under low contractility, ventricular fibrillation, high pulmonary artery pressure, and low circulatory blood volume conditions. In conclusion, a proper RVAD-LVAD balance should be maintained by avoiding RVAD overdrive. Additional studies will further investigate the performance of these pumps in chronic animal models.     

Intra-abdominal pressure changes during natural movements in man

The weight of the upper part of the trunk is partially transmitted to the pelvis via the vertebral column. If the muscle walls around the abdominal cavity are contracted, a high pressure can be generated within the cavity (>200 mmHg). The abdominal space can then transmit part of the weight to, e.g., the upper part of the body. Intra-abdominal pressure recordings have been performed during locomotion and other natural movements with intragastric pressure recordings. With each step, there is a phasic variation in pressure, with its peak coinciding with that of the peak vertical force exerted by the leg against the ground. The peak values increase progressively with the speed of walking/running up to a mean of 38 mmHg and with trough values of 16 mmHg. The phasic variations with each step is due to a phasic activation of the abdominal muscles, with an EMG activity starting 50 ms or more before foot contact. If an extra load is put on the back, the posture changes and at the highest speed of running the pressure values are significantly higher than without this additional load. After a jump down from a moderate height of 0.4 m, the average increase is 89 mmHg and can often exceed 100 mmHg. These pressure changes are large and will presumably act to unload the spine under the prevailing biomechanical conditions and, in addition, there will no doubt be an effect on the circulatory system.     

Intra-abdominal pressure changes during natural movements in man.

The weight of the upper part of the trunk is partially transmitted to the pelvis via the vertebral column. If the muscle walls around the abdominal cavity are contracted, a high pressure can be generated within the cavity (greater than 200 mmHg). The abdominal space can them transmit part of weight to, e.g., the upper part of the body, Intra-abdominal pressure recordings have been performed during locomotion and other natural movements with intragastric pressure recordings. With each step, there is a phasic variation in pressure, with its peak coinciding with that of the peak vertical force exerted by the leg against the ground. The peak values increase progressively with the speed of walking/running up to a mean of 38 mmHg and with trough values of 16 mmHg. The phasic variations with each step is due to a phasic activation of the abdominal muscles, with an EMG activity starting 50 ms or more before foot contact. If an extra load is put on the back, the posture changes and at the highest speed of running the pressure values are significantly higher than without this additional load. After a jump down from a moderate height of 0.4 m, the average increase is 89 mmHg and can often exceed 100 mmHg. These pressure changes are large and will presumably act to unload the spine under the prevailing biomechanical conditions and, in addition, there will no doubt be an effect on the circulatory system.     

The venous hypothesis of hydrocephalus

Pressure in the central nervous system (CNS) depends upon the volume of tissue that it contains. This includes blood, cerebrospinal fluid (CSF), nerves and any space occupying lesions. The dependency of pressure on volume arises because the CNS is confined by bone. Venous and CSF pressure is linked to overall pressure. Arterial pressure can increase in response to overall pressure to maintain arterial supply. Continuous arterial supply can be maintained because venous blood flows out of the CNS. Reduced volumes of arterial blood will enter the system if venous outflow is interrupted. Increase in CNS volume, as occurs with space occupying lesions, causes compression of veins. This may result in increased venous pressure and reduction in flow of blood out of the CNS. Cerebrospinal fluid (CSF) is extracellular fluid; its absorption back into the circulation is influenced by venous pressure. Any increased in CNS tissue volumes can therefore lead to CSF accumulation. This may then exacerbate the hydrocephalus by further increasing overall CNS volume. Free flow of CSF around the CNS facilitates venous drainage. Blockages to CSF flow can act like space occupying lesions. Chiari malformations, where the cerebellar tonsils obstruct the foramen magnum lead to reductions in CSF flow that can occur intermittently. This leads to impairment of venous drainage which may result in accumulation of CSF. The head or the spine can be affected together or separately. The manifestation of excess fluid accumulation is hydrocephalus and syringomyelia. The speed and origin of venous insufficiency influences the morphology of individual cases particularly with regard to lateral ventricle size. When pressure increases rapidly there may be little time for CSF accumulation. Oedema, compression of intracranial CSF spaces and cerebral ischaemia follows. When venous pressure is only slightly elevated CSF will accumulate and the manifestations of ischaemia may be less apparent, although ischaemia will be a feature of all instances of pathologically raised CNS pressure.