Development of home hemodialysis system with navigator

最近，日本有30多万慢性肾衰竭患者接受血液透析（HD）治疗。然而，这些透析患者的预期寿命估计大约是健康受试者的一半。为了促进病人的健康和长寿，需要进一步改进透析系统。在这种情况下，本研究的目的是开发具有安全导航仪的家庭血液透析系统。具体地说，在治疗过程中，透析器性能和溶质去除特性的连续监测系统已经开发出来，以便为每个患者导航最佳的透析条件。我们用全牛血或牛血浆进行了体外实验，以评估透析器的性能，如溶质间隙和水力渗透性。此外，在牛血浆实验中，用激光多普勒超声测量了透析器的内部过滤流速。利用navigator对透析液中溶质浓度进行了连续监测，为透析系统的开发提供了依据。得到了实验过程中水力渗透率、内滤流量和溶质去除效率等数据的时间过程。这些性能的时间依赖性似乎是由膜污染引起的，即蛋白质堵塞膜。我们建立了一个基于透析器质量传递和动量变化的透析器性能估计的分析模型。并对试验数据进行拟合，确定了水力渗透率等参数。在研究过程中，我们得出了一些结论，为家用导航仪透析系统的基础技术的开发和知识的收集做了一些工作。在不久的将来，需要开发具有导航系统的透析机，以便为每位患者提供最佳的透析。

In recently, more than 300,000 patients with chronic renal failure receive hemodialysis (HD) therapy in Japan. However, life expectancy of those dialysis patients estimates roughly half as that in healthy subjects. Further improvements of the dialysis system are required for promoting health and longevity of the patient. In this situation, the aim of this study is development of home hemodialysis system with navigator in safety. Concretely, continuous monitoring systems for dialyzer performances and solute removal characteristics during the treatment have been developed to navigate the optimal dialysis conditions for each patient.We carried out in vitro experiments with whole bovine blood or bovine plasma to evaluate the dialyzer performance such as solute clearances and hydraulic permeability. Furthermore, internal filtration flow rate of a dialyzer was measured using laser Doppler sonography during bovine plasma experiments. And, continuous monitoring of solute concentration in the spent dialysate was done for the development of the dialysis system with navigator.From these results, we obtained time courses of data for hydraulic permeability, internal filtration flow rate and solute removal efficiency during the experiments. Time dependency of those performances seems to be induced by membrane fouling, namely, protein plugging to the membrane.We have developed an analytical model for estimating the dialyzer performances based on mass transport and momentum change in the dialyzer. And some parameters such as hydraulic permeability were determined using the fitting method to the experimental data.During our study, we have reached some conclusionsDevelopment of fundamental techniques and collecting some knowledge are done for the dialysis system with navigator at home. Development of a dialysis machine with navigation system is required for optimum dialysis for each patient in the near future.