A catheter (10) is disclosed having a stepped coaxial construction formed by an internal tube (12) and an external tube (14). The internal tube includes a distal pressure lumen (26), a balloon inflation lumen (28), and a sensor lumen (30. The external tube includes the first proximal pressure lumen (48),...http://www.google.se/patents/US5108369?utm_source=gb-gplus-sharePatent US5108369 - Dual-diameter multifunction catheter
