Development of long term use menbrane oxygenator built-in artificial heart

由于心脏和肺由于这些密切相关的器官的广泛相互作用而经常同时衰竭，因此期望开发这样的装置以同时支持这些器官。在此背景下，我们开发了一种新型的长期心肺支持辅助系统：一体化人工心肺装置（IAHLD）。IAHLD由一个紧凑型氧合器和两个气动推板式人工心脏组成。氧合器由两层无孔膜中空纤维制成，其中在血液接触表面形成的致密层防止血清泄漏。将光纤封装在圆柱形聚氨酯封装（phi 60 mm X 70 mm）中，该封装也用作外壳。人工心脏具有带Bjork-Shiley瓣膜的入口（或出口）端口和直径为60 mm的耦合器。通过耦合器将人工心脏耦合到氧合器的每一个和每一个;因此，所有组件都是一体的。通过这种特殊结构，我们旨在避免低流量区域，这会导致血栓形成和气体交换恶化。在5L/min的血流量下，该装置的气体输送性能（气体交换面积1.5m^2，预充量400 ml）为氧气300 ml/min，二氧化碳250 ml/min。在60 kg的无功能心肺模型上，该装置可满意地替代全部心肺功能。在6小时的泵送过程中，山羊的血流动力学参数保持较稳定，血气分析PaO_2保持在300 mmHg以上，PaCO_2保持在30 mmHg以下。我们还在开发一种抗血栓表面处理技术：共价肝素结合技术。虽然这项研究还为时过早，但我们相信，在不久的将来，我们可以使其实用。

As the heart and lung frequently fail simultaneously due to the extensive interaction of these closely related organs, it has been expected to develop such a device as to support these organs at the same time. On the basis of this back ground, we have developed a novel assist system for long-term cardiopulmonary support ; an integrated artificial heart-lung device (IAHLD). The IAHLD consists of a compact oxygenator and two pneumatic pusher-plate type artificial hearts. The oxygenator is made of two layred non-porous membrane hollow fibers in which an ultrathin dense layr formed at the blood contacting surface prevents serum leakage. The fibers are potted in a cylindrical polyurethane potting (phi60 mm X 70 mm) which also serves as a housing. The artificial heart has an inlet (or outlet) port with a Bjork-Shiley valve and a coupler of 60 mm in diameter. The artificial heart are coupled to each and of the oxygenator with the coupler ; thus all components are incorporated. With this special structure, we intended to avoid low flow areas, which causes thrombus formation and gas exchange deterioration. The gas transfer performance of the prototype device (gas exchange area =1.5m^2, priming volume = 400 ml) was 300 ml/min for oxygen and 250 ml/min for carbon dioxide at a blood flow rate of 5 L/min. Venoarterial bypass using the prototype device could satisfactory replace the total cardiopulmonary function in a nonfunctioning heart-lung model of a goat weighing 60 kg. During 6 hours of pumping, hemodynamic parameters of the goat was maintained fairly stable and blood gas data was kept above 300 mmHg for PaO_2 and below 30 mmHg for PaCO_2. We are also developing a technique for thromboresistant surface treatment : covalent heparin bonding technique. Although this research is still premature, we believe that we can make it practical in a near future.