International Circulation: What are the latest development of ICD lead design and manufacture?

　　《国际循环》：ICD导线设计和制造的最新进展有哪些?

　　Harry Mond: When looking at the insulators， there are two major types of materials used， polyurethane and silicone rubber. Silicone rubber is very soft and easily damaged at the time of implanting. In this case， the physician is involved in the failure of the lead. When the material rubs against other components such as the ICD can， it can cause creep and the insulation bearing the conductor is just wearing away. The problem with polyurethane is that， for the soft ones， they are also prone to deterioration in the body， which is very hostile to these materials. You can get stiff polyurethanes， which are very strong and good but too stiff to be used in a lead. What we tend to do is that we make a compromise by covering the silicone rubber insulation with a tube of polyurethane， whether it is the stiff or soft polyurethane. The method does help protect the silicone rubber from the abrasive effect as well as the damage during implantation. One very interesting change has been the introduction of new materials that may be better for the future. Insulators are generally very cheap and not an expensive part of the lead. However， to introduce a new material is an extremely expensive exercise， which the companies can find overwhelming if they spend too much money doing it. There has then been a general reluctance to change materials. But we realize now that we just have to change. As a result， there has been some work coming out of Australia where a hybrid material taking the molecular structure of both polyurethane and silicone is developed. By taking out some components of polyurethane and replacing with silicone， you can make a hybrid material that is just perfect for use in ICD leads. It will not be destroyed by the body. It will have the ability to obtain the strength of the stiffer polyurethanes and the characteristics of the softer silicones. These new materials have been introduced now. Their use in implantation is still a short history， maybe only one or two years. However， animal studies have been going on for 6-7 years and suggest that these new materials are definitely the way to go for the future. The short worldwide experience to date has been perfect with no problems being found with this material whatsoever.. It is looking good on the horizon as far as new insulation materials are concerned.

　　Harry Mond教授：ICD导线的绝缘层主要有两种类型的材料组成：聚氨酯和硅胶。硅胶非常柔软，极易在移植术程中损坏。当硅胶材料与其他组件譬如ICD外壳摩擦时，就会发生濡变，包裹导体的绝缘层就会磨损。软性聚氨酯与硅胶一样在体内也易于损坏，体内环境与这种绝缘材料有一定的不兼容性;较硬的聚氨酯非常耐用但是太硬而不能被用作导线。我们做了一种中间产物，在硅胶绝缘层上覆盖一个或软或硬的聚氨酯管子，这种方法的确有助于保护硅胶避免磨损以及减少其在植入过程中的损害。新材料的引进是必需的。绝缘体通常非常便宜，不是导线中昂贵的部分。然而，引进一种新的材料却是一件非常昂贵的事，如果花费大量的钱财在绝缘材料方面，许多公司会承受很大的压力，因此普遍都不情愿改变绝缘体的材料。但是我们现在意识到这种情况必须改变。目前澳大利亚正在发展一种混合材料，其分子结构是聚氨酯和硅胶的结合，通过去掉聚氨酯中的某些成分代之以硅胶，用作ICD导线非常完美。这种材料在体内不会被损坏，同时具备硬聚氨酯的强度和软硅胶的优点。现在这些新材料已经引入临床，但应用时间比较短暂，可能只有1或2年的时间。然而，动物实验已经进行了6-7年，提示这种新材料必将成为未来的方向。迄今为止，关于这种材料的世界范围短时间内应用的经验是完美的，没有发现什么问题。所以从绝缘材料这一方面来看，前景乐观。