An indwelling device for passing fluids into or out of the body includes an inflatable cuff for lodging the device within a body passage. The inflatable cuff is inflated with a fluid such as saline. Prior to the inflation process a dye dispersant material such as methylene blue is incorporated in dry...http://www.google.co.uk/patents/US5103817?utm_source=gb-gplus-sharePatent US5103817 - Automatic dye dispersant for endotracheal tubes and catheters
