4. Implantable medical devices

Several implantable medical devices are used in the treatment of the diseases mentioned in the previous paragraphs. They can be divided into two categories:

• extracorporeal short-term devices such as membranes for artificial organs (kidney/heart/lung), tubes and catheters for blood transport;

• long-term in situ implants such as vascular implants and implantable artificial organs.

The most important requirement for these implants is blood compatibility. Blood coagulation is the most important aspect of blood compatibility: the implant must not cause blood to clot. In addition, implants must not damage proteins, enzymes and blood components (red blood cells, white blood cells and platelets). Implants must not cause hemolysis (rupture of red blood cells) or release of platelets....