| abstract |
An intraparenchymal infusion catheter system for delivering drugs or other agents to selected sites in an organism, such as a human, includes a pump that may be implanted or disposed outside the organism. A catheter is coupled to the pump. The catheter comprises a flexible biocompatible tubular portion terminating in a free distal end. The distal end of the catheter bears a rounded tip, a portion of which is slidably disposed within the lumen of the tubular portion. The tip is porous for discharging an agent or drug to a selected site. The tip has a microporosity of less than or equal to 0.22 microns. The tubular portion is composed from a material that will expand from its nominal size when exposed to a stimulus such as heat or a solvent and return to its nominal size when the stimulus is withdrawn. By expanding the tubular portion, a physician can select the amount of the tip that is exposed to the organism, thereby customizing the catheter to the structural size of the selected site within the body. |